JPH02256977 | FLOW CONTROL VALVE |
JP2001174107 | REFRIGERATION SYSTEM |
JP4546751 | Rotary electric valve |
KUNOW PETER (DE)
LENZ NORBERT (DE)
BIESTER KLAUS (DE)
KUNOW PETER (DE)
LENZ NORBERT (DE)
WO2003026112A2 | 2003-03-27 |
DE20115474U1 | 2003-02-20 | |||
EP1316672A1 | 2003-06-04 | |||
US41551003A | 2003-07-21 | |||
EP0112547W | 2001-10-30 | |||
DE20018560U1 | 2002-03-21 | |||
US48957304A | 2004-08-05 | |||
EP0210471W | 2002-09-18 | |||
DE20115471U1 | 2003-02-20 | |||
US48958304A | 2004-08-05 | |||
EP0210468W | 2002-09-18 | |||
DE20115473U1 | 2003-02-20 | |||
US48945304A | 2004-03-11 | |||
US48958404A | 2004-08-05 | |||
EP0210469W | 2002-09-18 | |||
US6039119A | 2000-03-21 | |||
US27620402A | 2002-11-12 | |||
EP0105156W | 2001-05-07 | |||
DE20008415U1 | 2001-09-13 | |||
US27620102A | ||||
EP0105158W | 2001-05-07 | |||
DE20008414U1 | 2001-09-13 | |||
US34492103A | 2003-02-18 | |||
EP0109513W | 2001-08-17 | |||
EP0117841A | 2000-08-18 | |||
US41541903A | 2003-10-01 | |||
EP0112551W | 2001-10-30 | |||
DE20018564U1 | 2002-03-21 | |||
US41569601A | ||||
EP0112548W | 2001-10-30 | |||
DE20018562U1 | 2002-03-21 | |||
US46711201A | ||||
EP0112550W | 2001-10-30 | |||
DE20012168U1 | 2000-11-30 | |||
US41551101A | ||||
EP0112554W | 2001-10-30 | |||
DE20018548U1 | 2002-03-21 | |||
US41541803A | 2003-09-04 | |||
EP0112549W | 2001-10-30 | |||
DE20018563U1 | 2002-03-21 | |||
DE20311033U1 | 2004-11-25 |
Moreover, it is ensured through the number of the converting units 180 that, when one, two, three or even more converting units 180 fail, a complete failure of the voltage supply to the electrical device need not be feared, because the converting units 180 that are still operative can be clocked to receive more voltage on the input side and convert the input voltage into the output voltage required. It is therefore the object of the present invention to provide a DC converter 86 that is structurally simple and is able to reliably convert high DC voltages even in the case of high power, in such a way that the reliability of the converter 86 is increased and cooling systems entailing high costs can be dispensed with. As shown in Figure 5, the DC converter 86 may comprise a plurality of DC converter components 180, each of said DC converter components 180 being, on the input side, serially connected to the control and supply assembly 70 and, on the output side, connected in parallel to the cable connection 186 so as to provide the converted DC voltage for the electric device 46. In at least some embodiments, the converting units 180 may be spaced apart from one another such that they do not mutually affect one another in their heat development, and each converting unit 180 can thus be cooled separately. Depending on the number and design of the converting units, DC voltages of about IkV to 1OkV and, in particular, 3kV to 8kV may be present on the input side. It should once again be pointed out that even higher input voltages with a correspondingly high power can be converted if the number of the converting units 180 or their corresponding construction is matched accordingly. Care should be taken such that the breakdown strength of the components of every converting unit 180 is at least so high that the amount of the input voltage to be converted by the converting unit 180 is smaller than the breakdown strength. To implement highly efficient converting units 180 that, consequently, only generate a small amount of heat and thus ensure a high reliability and, economically speaking, are excellent in production and operation at the same time, a corresponding DC voltage converting unit 180 may be designed as a clocked switch mode power supply 126. In comparison with, e.g., linear controlled power supplies 182, a clocked switch mode power supply 126 offers advantage such as smaller size, less noise development, reduced smoothing demands and an increased input voltage range. Various realizations of such a clocked switched mode power supply 126 are known. The first subdivision that can be carried out is a division into switched mode mains power supplies 126 clocked on the secondary side and those clocked on the primary side. In both said fundamental versions, it is possible that a current flows constantly into a storage capacitor of the switched mode mains power supply 126 or that a current is only discharged at certain time instances so that the converter in question is referred to as a feed forward converter or a flyback converter 130. In order to obtain a compact and reliable component, the switched mode mains power supply 126 can, for example, be implemented as a flyback converter 130. This flyback converter 130 can preferably be clocked on the primary side so as to obtain a galvanic separation between the input and output sides, and it can be a single-phase or a push-pull converter. Single-phase converters are, in this context, advantageous insofar as they normally require only one power switch as a clock switching means 150. This power switch 150 can be implemented e.g. as a power MOSFET or as a BIMOSFET. In addition, also thyristors may be used as clocked switching means 150 especially when high power values in the kilowatt range are involved. The above-mentioned switched mode mains power supplies 126 have, especially in the case of higher power values, a plurality of advantages, such as a lower dissipation power, a lower weight, a smaller volume, no generation of noise, less smoothing outlay and a larger input voltage range. Switched mode mains power supplies 126 and especially also flyback converters 130 are used in a great variety of fields of application, such as microwave ovens, computers, electronic adapting equipment for fluorescent lamps, industrial and entertainment electronics, screens, cardiac defibrillators and the like. Flyback converters 130 are also excellently suitable for use in fields of application where a high power is required on the output side. The switch mode power supplies 182 can be subdivided into primarily and secondary clocked switch mode power supplies 182. The secondary clocked switch mode power supplies 182 include, for instance, step-down and step-up converters. However, in order to realize an electrical isolation between input and output, primarily clocked switch mode power supplies 182 and, in particular, flyback converters 130 may be used according to the invention as converting units. Such flyback converters 130 are also called isolating transformers. Figures 6-8 are described in U.S. patent application Serial No. 10/489,584 filed March 12, 2004 and entitled DC Converter, which claims the benefit of PCT/EP02/ 10469 filed September 18, 2002, which claims the priority of DE 201 15 474.9 filed September 19, 2001 (1600-09600; OTE- 030455 US), all of which are hereby incorporated herein by reference in their entirety. Figure 6 shows a simplified embodiment for a push-pull converter 238 used as a switched mode mains power supply 182. This push-pull converter 238 has its input terminals 192 and 194 connected in series with the other push-pull converters 238 or switched mode mains power supplies 182 according to Figure 5. On the input side, the push-pull converter 238 may comprise a Zener diode 240 and an input capacitor 196. These two components are connected parallel to each other and to a primary winding of a transformer 92. The Zener diode 240 can be composed, in a manner known per se, of a number of transistors and load resistors. The primary winding of the transformer 92 has associated therewith a switching means 200. This switching means 200 is shown as a simple switch in Figure 6. In actual fact, such switching means 200 is, however, realized by one or more switching transistors 222, 224, 226 and 228, cf. e.g. Figures 7 and 8; such switching transistors may be power MOSFETs, BIMOSFETs or thyristors. The primary winding is magnetically coupled to a secondary winding of the transformer 92. The secondary winding is connected to output terminals 206 and 212 of the push-pull converter 238. A diode 202 and a load 204 are serially connected between the primary winding 104 and the output terminal 206. The load 204 may e.g. be an inductor 208 according to Figures 7 and 8. The output terminals 206 of all push-pull converters 238 or switched mode mains power supplies 182 according to Figure 5 are connected parallel to one another and to the connection 186. The other output terminals 212 are also connected parallel to one another and to ground 214. On the output side of the push-pull converter 238, a smoothing capacitor 210 is connected parallel to the secondary winding of the transformer 92. In Figures 7 and 8 a respective push-pull converter 238 according to Figure 6 is shown in detail, in one case as a full-bridge push-pull converter 242 and in another case as a half-bridge push pull converter 244, both push-pull converters 242 and 244 being shown with the respective circuit. Such circuits for full-bridge and half-bridge push-pull converters 242. 244 are known per se. The circuits shown differ from known circuits with regard to the respective connection modes of the push-pull converters on the input side and on the output side, i.e. with regard to the fact that respective terminals are serially connected on the input side and connected in parallel on the output side. Furthermore, the Zener diode 240 on the input side of each push-pull converter 238 or 242, 244 is connected parallel to the primary winding of the transformer 92. This Zener diode 240 serves as an input-side load of the various push-pull converters 238 for powering up the system with regard to voltage and energy already prior to connecting or additionally connecting a respective electric device 46, 24. As long as the electric devices 46, 24 have not yet been connected or additionally connected, the respective energy in the system is consumed and converted into heat by the Zener diode 240. When the electric devices 46, 24 are then additionally connected, energy distribution takes place in each of the push-pull converters 238, and it is only a small percentage of the energy that is still converted into heat by the Zener diode 240. Due to the large number of Zener diodes 240 and the fact that they are arranged in spaced relationship with one another, the electric energy converted into heat in said Zener diodes 240 will not result in overheating of the DC converter 86, but, depending on the location where the converter is arranged, it can be discharged directly into air or water as waste heat. Complicated and expensive cooling systems can be dispensed with. When the electric devices 46 of remote assembly 25 no longer need electric energy, they will be switched off, i.e. disconnected from the system. Subsequently, the whole energy is, in situ, again converted into heat by the Zener diode 240. If the electric device 46 in question or another electric device 46 is then not connected or additionally connected once more, the system as a whole can be run down to a lower voltage, such as 3000V or even less than that. The reduced voltage is then still required for the function of the controller and of other units of the DC converter 86 which are always in operation. In the full-bridge push-pull converter 242 according to Figure 7 a total of four switching transistors 222, 224, 226, 228 are integrated in the switching means 200. The switching transistors 222, 224, 226, 228 co-operate in pairs for effecting a push-pull activation of the transformer 92, the push-pull clock cycle ratio being 1:1. On the output side, respective diodes 202 are provided, and on the input side a plurality of input capacitors 196 are provided. For activating the various switching transistors 222, 224, 226, 228, a pulse modulation means 230 may be implemented as shown in Figure 8. This pulse modulation means 230 outputs a series of pulses whose widths and/or heights and/or frequencies are variable so as to clock the switching transistors 222, 224, 226, 228. For the sake of clarity, the pulse modulation means 230 is not shown in Figures 6 and 7. As previously described, there are electric devices, which require both a high voltage and a high power. If the power and the voltage are suddenly demanded, when the electric device 46 is switched on, and are not yet available, the power and supply assembly 70 may collapse due to a feedback caused by the sudden request or large amount of power. Ih order to avoid such a collapse and a negative feedback, the clocked switched mode mains power supply 182 has on the input side thereof a load 240 which is connected in parallel to the transformer 92 of such switched mode mains power supply 182. The DC converter 86 according to the present invention is so conceived that, already prior to switching on or supplying the electric device 46, the voltage and the power in the control and actuation assembly 80 are increased to at least the values demanded by the electric device 46. Until the electric device 46 actually operates, the voltage drops across the load 240 and the power is converted into heat as dissipation power. Only when the electric device 46 demands power, will the power across the load 240 be supplied to the electric device 46. For the DC source, a stable utilization and a constant load are always discernible, i.e., the respective power distribution takes place in situ and is no longer fed back to the supply and control assembly 70. As described above, the load 240 can be implemented as a Zener diode 240 so that, if necessary, voltage and power can be built up rapidly to desired values only a short time before they are demanded by the electric device. Full voltage and full power can in this way be built up within a few milliseconds and consumed by the Zener diode 240. The electric device 46 is only connected or additionally connected when voltage and power have been built up completely. The voltage and the power are then supplied to the electric device 46, only a residual voltage dropping across the Zener diode 240 and only a small percentage of the power (a few percent) being consumed there. If the electric device is then switched off, the whole voltage will again drop across the Zener diode 240 and said Zener diode 240 will consume the full power in the system. Subsequently, the voltage and the power can be reduced to a lower value. The reduced values are sufficient for supplying respective components of the system, such a monitoring and control means, which are also active if no electric device has been connected or additionally connected. If a supply of components by the DC converter 86 according to the present invention is not necessary, the voltage and the power can also be switched off completely or reduced to zero. As soon as there is again a demand from an electric device, voltage and power are again built up within a few milliseconds. In some embodiments, the Zener diode 240 can be implemented in the form of field effect transistors or load resistors. Furthermore, the Zener diode 240 also guarantees in each converter component 182 a good heat dissipation of dissipation power that has there been converted into heat. The heat in question is no longer generated locally within close limits, but it is generated at a large number of locations so that the heat can be given off directly into the air or into water or the like. Separate cooling systems are not necessary. Furthermore, the Zener diode 240 may have a very steep limiting characteristic so as to stabilize the output voltage still further, if necessary. If the Zener diode 240s and the respective converter components have the same type of structural design, it is also guaranteed that identical current intensities are distributed to each component. The voltage is stabilized up to a range of 2,3 or 5 % at the most. In at least some embodiments, to increase a cutoff frequency of the filter 184, the switch mode power supplies 182 of the DC converting device 86 may be clocked with respect to one another in phase-shifted fashion. To produce corresponding harmonics only to a small degree in this connection, a phase shift in the clocking of neighboring switch mode power supplies 182 may be 1/n each if n is the number of the switch mode power supplies 182 of the DC voltage converting device 86. Hence, the phase shift is such that the n+lth switch mode power supply 182 would be again in phase with the first switch mode power supply 182 (cyclic phase shift). The switched mode mains power supplies 182 of the DC converter 86 can be clocked in a phase shifted mode so as to shift, especially in the case of the communication connection in the direction of the supply and control assembly 70, the cutoff frequency of clocking interference. Such a push-pull converter 182 may be designed as a half-bridge or full-bridge push-pull converter 232. In particular for maximum powers the switch mode power supply 182 may be designed as a full-bridge push-pull converter 232. Such converter components 180 for an input voltage of e.g. a few hundred volts are nowadays commercially available, whereas converter components for a few thousand or for several thousand volts on the input side are not available at all or are at least very expensive and complicated. The parallel connection of the converter components 180 on the output side results, depending on the power of the individual converter components 180, in the total power of the system. Depending on the total power desired, the number and the structural design of the converter components 180 are selected accordingly. The overall system can easily be adapted to given requirements in this way. In order to satisfy requirements with respect to the control of mains fluctuations and load control, the tendency towards miniaturization and the wish for reducing the dissipation power, the converter components 180 can be implemented as clocked switched mode mains power supplies 182. Such clocked switched mode mains power supplies 182 have, in comparison with conventional power supply units, an efficiency that is in some cases higher than 90%, a reduction of volume and weight of up to 60%, a voltage stabilization of less than 1-2 %, they require only a small amount of filtering means and their price-performance payoff is more advantageous. It can also be considered to be advantageous when the switched mode mains power supply 182 is clocked on the primary side so as to galvanically separate the output side and the input side. The switched mode mains power supply 182 can be implemented as a push-pull converter 188 so as to use a switched mode mains power supply 182 which is also well adapted to high power values. The push-pull converter 182 can be implemented as a half-bridge or as a full-bridge push- pull converter. The switched mode mains power supply 182 can include a switching transistor, 222, 224, 226 and 228 especially a power MOSFET or a power BMOSFET, so that a transformer of the switched mode mains power supply 182, which is clocked on the primary side, can be switched electronically in a simple way. In this connection, attention should be paid to the fact that, e.g. for a full-bridge push-pull converter, four such switching transistors 222, 224, 226 and 228 are respectively connected in pairs. The switching transistors 222, 224, 226 and 228 can be clocked in a push-pull mode with a clock cycle ratio of 1:1 so as to obtain a low current consumption of the transformer in the push- pull converter. In order to obtain the least possible amount of harmonic waves on the output side, the switched mode mains power supplies 182 of the DC converter 86 can be clocked synchronously. To control the switching transistors accordingly, the switch mode power supply may comprise a pulse modulation means for the clocked control of the switching transistors 222, 224, 226 and 228, the pulse modulation means supplying a sequence of pulses of a variable width and/or height and/or frequency for clocking the switching transistors 222, 224, 226 and 228. In order to activate the switching means of the various switched mode mains power supplies 182 while controlling or regulating especially the controller, the switched mode mains power supply 182 can be provided with a pulse modulation means which outputs a series of pulses having variable widths and/or heights and/or frequencies so as to clock the switching means in question or rather the switching transistors 222, 224, 226 and 228 defining the same. A switching means for correspondingly switching the transformer of the switch mode power supply may e. g. be designed as a switching transistor, in particular a power MOSFET or BIMOSFET. It is also possible that the switching means is designed as a thyristor. In a push-pull converter, at least two switching transistors 222, 224, 226 and 228 are used that operate in the push-pull mode. Advantageously, it is also possible to operate in the push-pull mode with a clock ratio of 1:1. This means that both switching transistors 222, 224, 226 and 228 are each switched through alternatingly for the same periods of time. To obtain an output voltage that is as smooth as possible and has a relatively small amount of harmonics, the switch mode power supplies 182 of the DC converting device 86 may be clocked in synchronism. This means that all switch mode power supplies 182 are clocked at the same clock rate. To ensure an undisturbed transmission of a communication connection in this respect and to scan the DC voltage on the input side substantially completely at the same time, the clock rate of the switch mode power supply may be in the range of 1OkHz to more than IMHz and, in particular, in the range of 50IdHz to 300IcHz. In this connection each switch mode power supply 182 can e.g. be readjusted in its output voltage via changes in the duty factor, in particular, in case of failure of another switch mode power supply 182 of the DC voltage converting device 86. In the simplest case a readjustment of the output voltage of a switch mode power supply 182 can take place via a change in the duty factor of the switching transistor. To be able to transmit data sent via the cable connection in the direction of the DC voltage source, i.e. without interference and at a high speed, the DC voltage converting device 86 may comprise a filter means 190 arranged upstream on the input side. In connection with the filter means 190, it should additionally be mentioned that such means filters, in particular, the frequency range within which the communication connection to the DC voltage source takes place. This means that only a lower frequency range of up to e.g. 50IcHz is filtered. Relatively simple and inexpensive filters are thus sufficient. In order to remove interfering frequencies especially from the frequency range required for the communication connection, the DC converter 86 can be provided with a filter means 190 preceding such DC converter 86 on the input side thereof. This filter means 190 filters especially a frequency range of up to approx. 50IcHz. In order to realize suitable communication connection in a simple way and only after the filtering, a means for coupling data signals in/out 84, 136 can be connected upstream of said filter means 190 in the direction of the DC source. It should additionally be pointed out that the filter means 190 between the DC converter 86 and the DC voltage source can be realized e.g. by comparatively small capacitors, since, due to the fact that the individual converter components are clocked in a phase-shifted mode, the cutoff frequency of the system is very high. To monitor, control and regulate the corresponding components of the DC voltage converting device 86 on site, a controller 112 may be assigned at least to the DC voltage converting device 86 and the components thereof. However, the controller 112 may also be responsible for electrical devices supplied by the converting device with DC voltage and may monitor the same in their function and carry out the control or regulation of the devices. The controller 112 used according to the invention can be designed in its monitoring function such that it monitors e.g. the individual switch mode power supplies, reports on the failure of corresponding switch mode power supplies and the location of said switch mode power supplies within the DC voltage converting device 86 and sends an alarm message in case of failure of a predetermined number of switch mode power supplies. The corresponding information of the controller can be transmitted via the coaxial cable connection to the DC voltage source that is located far away, and can be represented there accordingly. A controller 112 can be associated with at least the DC converter 86 and the components thereof so as to design the DC converter 86 in such a way that said DC converter 86 and, if necessary, also the electric device 46 connected thereto can be can be controlled and monitored automatically. This controller 112 can e.g. detect failure of a converter component and, if desired, also the position of said converter component. This information can be transmitted via the communication connection and the means for coupling data signals in/out 84, 136 to the DC source and the units associated therewith. There, the information can be displayed in a suitable manner on a reproduction device, such as a screen or the like. If a relevant number of converter components failed, a repair demand can additionally be supplied by the controller. The cable connection 68 may comprise at least one coaxial cable so that, even if high power is to be transmitted and if voltage and data are transmitted simultaneously, said cable connection can be established such that it has a small cross-section, whereby costs will be saved, especially in the case of long distances. Since the voltage transmitted through the coaxial cable is a DC voltage, only line losses will occur, whereas additional attenuation losses, which are caused by a transmission of AC voltages, are avoided. Referring again to Figure l(C), electrical devices 46 or electrical units 24 maybe a combination of actuators, sensors, motors, and other electrically operated equipment disposed at a remote assembly 25. The remote assembly 25 may include a subsea wellhead assembly with a subsea tree. By way of example, the wellhead assembly shown and described in U.S. Patent 6,039,119, hereby incorporated herein by reference, with a spool tree as described therein may be used with the embodiments of the present invention. The subsea tree may also be a dual bore tree. The electrical devices 46 may be actuators, which operate devices such as valves, chokes, and other devices that are used to control the flow of fluid through a subsea system, hi the preferred embodiments, the electrically operated subsea system eliminates the use of hydraulically actuated valves. Therefore, control and operation of a subsea assembly 25 can be all electrically controlled. An all electric system offers many advantages, such as quick response, elimination of hydraulic fluid, no dumping of fluid to sea (environmentally friendly), and the ability to perform real time diagnostics on the actuators, valves, and chokes of the assembly 25. At the surface, the requirement for a hydraulic power unit is eliminated and the surface equipment can be packaged more compactly. The following embodiments describe exemplary electrical devices 46 and electrical units 24 that may be used with the electric control and supply system 60 of the present invention. Referring now to Figure 9, there is shown a section through an electrical device 46 of a remote subsea assembly 25. The electrical device 46 is an actuator system 250 constructed in accordance with U.S. patent application Serial No. 10/276,204, filed November 12, 2002 and entitled Actuating Device, which claims the benefit of PCT/EPO 1/05156 filed May 7, 2001, which claims the priority of DE 200 08 415.1 filed May 11, 2000 (1600-07500; OTE-030295); all of which are hereby incorporated by reference herein in their entirety. Actuator system 250 is mounted via flange housing 286 to a control device 252 in the form of a gate valve. The actuator system 250 includes a system enclosure 254 laterally flanged to one side of the control device 252 with an actuator element 260 slide-mounted in the axial direction 256 to permit shifting between an extended position 262 and a retracted position 264. The actuator element 260 is connected to a valve slide 258 that is reciprocably disposed within the control device 252 so that the valve slide 258 can be shifted in the shift direction 276. In the extended position 262, the actuator element 260 is extended so as to shift the valve slide 258 within a slide bore 270 of the control device 252 to a position where it opens a transverse flow bore 272 through the valve gate 252 and through the valve slide 258. In its retracted position 264, the valve slide 252 closes the flow bore 272 through the valve gate 252. At least one return spring 266 is mounted on the other side of the control device 252 to subject the actuator system 250 to a pressure load in the reset direction 268. A connecting line 280 connects the actuator system 250 with the control and actuation assembly 80. The connecting line 280 is used for controlling the actuator system 250 and for data transfer. Referring now to Figure 10, there is shown a longitudinal section through the actuator system 250. In the upper half of Figure 10, the actuator element 260 is shown in its retracted position 264 and in the lower half, separated by the axis line 256, the actuator element 260 is shown in its extended position 262 as in Figure 9. The enclosure 254 is a two-part system having an inner enclosure section 282 removably attached to an outer enclosure section 284. The outer enclosure section 284 houses a power assembly 290 including an electric motor 292, for instance a direct-current servomotor, that is connected to a drive assembly 294, which may comprise a standard clutch-and-brake combination or alternatively a so-called flex-spline drive without the traditional gears. It should be appreciated that motor 292 preferably uses DC voltage but may use AC voltage. Power is supplied to motor 292 by subsea power source 102 via a connecting lines such as line 186. Connecting sleeve 298 is connected to drive assembly 294 on one end and to ball nut 306 at its opposite end. Rotating spindle 310, in the form of a ball screw 312, is suspended in the ball nut 306 and is adapted to move relative to the ball nut along axial direction 256. The drive assembly 294 turns the connecting sleeve 298 and the rotation is transferred to the ball nut 306, causing the rotating spindle 310 translate relative to the ball nut 306. A positional sensor 295 is disposed on the outer end section 284 to detect the longitudinal position of the spindle 310. The positional sensor 295 protrudes from the enclosure end section 284 and is positioned inside a sensor cap 316 that is detachably connected to the enclosure end section 284. The sensor 295 would detect for instance the respective longitudinal position of the rotating spindle 310 from which it determines the position of the actuator element 260. At its end on the side of the rotating spindle 310, the actuator element 260 is connected to a rotary mount 338. Radially protruding from the rotary mount 338 are two mutually opposite guide lugs 342 which engage in corresponding guide slots 344 in the rotating sleeve 330 and are guided by these slots in the axial direction 256. By engaging in the guide slots, the guide lugs cause the rotary mount 338 and thus the rotating spindle 310 and the rotating sleeve 330 to be rigidly connected to one another. [002] Volute spring 318 permits rotation of the connecting sleeve 298 in the advance direction 320 while preventing any rotation in the reverse direction. A second volute spring 332 is disposed between casing 324 and rotating sleeve 330. At one of its coil ends, the volute spring 332 makes contact with an inside surface of a tensioning sleeve 356 that engages in a gear 362 that is turned by a tensioning motor 364. The tensioning motor 364 is positioned between the casing 324 and the system enclosure 254 and can be controlled independent of the electric motor 292 for turning the tensioning sleeve 356. The tensioning motor 364 is connected to the control and actuation assembly 80. [003] A return spring 366 in the form of a torsion spring is connected to tensioning sleeve 356 such that, when the tensioning motor 364 turns the tensioning sleeve 356, it tensions the return spring 366, producing the necessary return force for the tensioning sleeve 356. The combination of tensioning motor 364, tensioning sleeve 356, volute spring 332 and return spring 366 constitutes an emergency release unit 370 which causes the actuator element 260 to be automatically reset into its retracted position 264 in the event of an electric-power failure in the actuator system 250. In operation, the actuator element 260 is moved in the shift direction 276 by operating the electric motor 292, which, by way of the drive assembly 294, turns the connecting sleeve 298 and the ball nut 306. As the ball nut 306 turns, the rotating spindle 310 or ball screw 312 is moved in an axial direction 256 which, by way of the rotary mount 338, moves the actuator element 260 in the direction of the extended position 262. The corresponding longitudinal movement of the rotating spindle 310 is monitored by the positional sensor 295. As shown in Figure 2, with actuator element 260 in the extended position 262, the valve 252 is open, allowing gas, oil or similar exploration or extraction to take place. Either simultaneous with or before operation of motor 292, tensioning motor 364 turns the gear 362 and with it the tensioning sleeve 356, causing the volute spring 332 to be relaxed and the return spring 366 to be tensioned. If and when the tensioning motor 364, designed as a step motor, is fed a corresponding holding current by control and actuation assembly 80, it will hold its position, as will the tensioning sleeve 356. The return spring 366 stores energy which tries to turn the tensioning sleeve 356 back against the holding force of the tensioning motor 364. If the actuator element 260 is to be moved, the holding force of the tensioning motor 364 is brought down by appropriate controls in control and actuation assembly 80. This will then release the volute spring 332, enabling the rotating sleeve 330, powered by the return energy of the return spring 366, to rotate in the opposite direction relative to the casing 324. By virtue of the rigid connection between the rotating sleeve 330 and the rotating spindle 310, provided by the guide slots 342 and guide lugs 344, the rotating spindle 310 and ball nut 306 can reverse direction toward the electric motor 292, whereby the actuator element 260, connected to the rotating spindle 310, is shifted back into its retracted position 264 (see Figure 9). A major factor in this context is the return force applied by the return spring 366 on the actuator element 260 since it is essentially this force that resets both the actuator element 260 and the rotating spindle 310 by turning back the tensioning sleeve 356 and correspondingly releasing the volute spring 332. hi the event of a power failure as well, the holding force in the tensioning motor 364 subsides, causing an emergency closure of the actuator system 250 due to the action of the return spring 366, volute spring 332 and tensioning sleeve 356. As described further above, the return spring 366 turns the tensioning sleeve 356 back, releasing the volute spring 332, so that the rotating sleeve 330 can then rotate relative to the casing 324. The remainder of the closing process takes place in the same way as in a normal closing operation of the actuator system 250. Figure 11 is a frontal illustration of the actuator system 250 per Figure 10 viewed in the direction of the outer enclosure end section 284 and the sensor cap 316. Figure 10 represents a sectional view along the line II-II in Figure 11. Four compensators 372, shown in more detail in Figure 12, are mounted in a concentric arrangement around the positional sensor 295 per Figure 11. Figure 12 represents a section along the line IV-IV in Figure 11. The compensators 372 are positioned in the outer enclosure end section 284 in a radial configuration relative to the electric motor 292. These compensators 372 serve to compensate for volume and pressure variations relative to a complete oil filling of the actuator system 250, i.e. they compensate for volume changes due to system actuation and to temperature fluctuations. Referring now to Figures 13 and 14, actuator system 250 may also include an externally activated emergency actuator assembly 378 in accordance with U.S. patent application Serial No. 10/276,201, filed November 14, 2002 and entitled Actuating Device which claims the benefit of PCT/EP01/05158 filed May 7, 2001, which claims the priority of DE 200 08 414.3 filed May 11, 2000 (1600-07400; OTE-030297), all of which are hereby incorporated by reference herein in their entirety. The emergency actuator 378 includes an auxiliary trunnion 380, with diametrically opposite pins 381 for attaching from outside the actuator system 250, such as with an underwater manipulator or similar tool. Auxiliary trunnion 380 may be located adjacent to position-monitoring sensor 295. Figure 13 shows an end view of system 250 while Figure 14 shows a longitudinal section along the line A-C in Figure 13. The motor 292 and the tensioning motor 364 each feature, respectively, a motor shaft 382 or a tensioning-motor shaft 404, projecting toward trunnion 380. Motor shaft 382 is equipped with a gear 388 in the form of a free-wheeling gear with a coaster mechanism 390, thus constituting a directional clutch unit 392. The free-wheeling gear 388 engages in a drive gear 395, which is mounted on one end of the trunnion 380, with a slip-ring coupling 394 interpositioned between them. Tensioning-motor shaft 404 connects to a sleeve nut 406 that supports a tensioning gear 414. As can be seen in Figure 13, tensioning gear 414 is rotated by the rotation of trunnion 380 via drive gear 395 and intermediate gear 418. Therefore, rotation of trunnion 380 rotates both a motor shaft 382 and a tensioning-motor shaft 404. The combination of auxiliary trunnion 380, drive gear 395, free-wheeling gear 388, tensioning gear 414, and tensioning motor shaft 404 forms and emergency actuator assembly 378 by means of which, in the event power to the motor 292 or to the tensioning motor 364 is interrupted or some other problem interferes with the normal operation of the actuator system 250, the actuator element 260 can be shifted into its operating position 276 as described above. The emergency actuator assembly 378 and its components remain in an idle standby state during normal operation, without requiring any further technical provisions, i.e. they are not moved in any way. If in an emergency situation the actuator element 260 is to be opened by the emergency actuator assembly 378, the auxiliary trunnion 380 is turned in the appropriate direction, in this case also turning the motor 292 by way of the free-wheeling gear 388 and coaster mechanism 390, as a result of which the actuator element 260 is shifted into its extended position 262, as described above. At the same time, by way of the intermediate gear 418 and the tensioning gear 414, the tensioning motor 364 is set in motion to activate the emergency release unit 370. The emergency release unit 370 is so designed that after only a few hundred revolutions of the tensioning-motor shaft 404, the volute spring 332 and return spring 366 are tensioned and by virtue of the slip-ring coupling 416, any further torque action on the tensioning motor 404 is prevented. If in an emergency situation the actuator system 250 must be used to close the actuator element 260, the auxiliary trunnion 380 is turned in the opposite direction. Only a few turns are necessary to trigger the emergency release unit 370. That unit 370 then works as described above, without the motor 292 turning along with it since in this case again the free-wheeling mechanism is activated. Figure 15 illustrates one embodiment of a position measuring sensor 295 as described in U.S. patent application Serial No. 10/344,921, filed February 18, 2003 and entitled Method and Device for Measuring a Path Covered which claims the benefit of PCT/EP01/09513 filed August 17, 2001, which claims the priority of EP 00117841.7 filed August 18, 2000 (1600-07700; OTE- 030305), all of which are hereby incorporated by reference herein in their entirety. In order to determine the position of a control element relative to a housing in the case of such a linear control device relative to the housing, one end of the control element may be connected with a spring element, which, with its end turned away from the control element, is connected with a force- measuring device, which transmits an electrical signal corresponding to the force transmitted from the spring element to the force-measuring device, to an evaluating device. This means that the linear control device is distinguished by the fact that the path-measuring device is incorporated in the latter. Correspondingly the path-measuring device in the linear control device can have the same features as the position-monitoring sensor described below. In the case of oil and gas recovery, in particular, a number of linear control devices are used. Such a linear control device is used, in particular, for operating valves, throttles or the like, in the case of oil and/or gas recovery, and has at least one control element mounted movable linearly within a housing and a drive device associated with the latter. The control element may be a ball spindle, which is mounted capable of turning in a corresponding nut. The nut is connected moving with the corresponding drive device and converts rotation of the nut induced thereby into a longitudinal motion of the ball spindle. The position-monitoring sensor 295 has a simple, strong, and reliable construction and is particularly suited for applications in remote and inaccessible areas. For example, one area of application is the use of the position-monitoring sensor 295, for the linearly actuator element 260 in a device for oil and/or gas production. Corresponding devices are so-called actuators, BOP's (blowout presenters), valves and the like, as are necessary in the case of oil and gas production. In this case, the area of application of the position-monitoring sensor 295 is not limited to uses on land, but because of the insensitivity to pressure or other unfavorable environmental influences, in particular the use under water is also possible. This obtains analogously for underground use. Referring now to Figure 14, the position-monitoring sensor 295 is situated underneath the auxiliary trunnion 380 and is operationally connected to the motor shaft 382 of electric motor 292 that is rotatable in the direction of advance rotation 320. Located next to the positional sensor 295, in the same recess in the motor cover or end section 284 is the plug connector 384 for the connection of a connecting line 186 by way of which data can be transmitted to or retrieved from the position-monitoring sensor 295 and actuator system 250 and power may be provided to power assembly 290. Referring now to Figures 15-17, there is shown an enlarged view of the position-monitoring sensor 295 as an example of path-measuring device according to the invention. The position- monitoring sensor 295 is located in a linear drive device 450, which has at least one operating element 452, which is movable back and forth in the longitudinal direction 256. Operating element 452 is preferably a ball spindle, which is mounted capable of rotating in a ball rotation nut. At the time of the rotation of the ball rotation nut by means of the drive device 450, shown only partially in Figure 15, there is a corresponding rotation of the operating element 452 and a motion of the operating element 452 in the longitudinal direction 256 takes place as a result of the rotation relative to the ball rotation nut in the longitudinal direction 256. Operating element 452 is connected at one end 454, per Figure 15, with spring element 456 of position-monitoring sensor 295. The spring element 456 is guided in a conduit 458 by drive device 450 and connected with its end opposite the operating element 452 with a corresponding force-measuring device 460 in the form of an electrical measuring conductor. The force exerted by the operating element 452 onto spring element 456 by means of the force-measuring device 460 or the corresponding electrical measuring conductor is converted into a corresponding voltage. The spring element 456 can be chosen in particular so that it expands proportional to the retaining force exerted, so that the evaluation of the signal of the force-measuring device 460 and correspondingly the determination of motion or position of the actuator element 260 is simplified. Since a spring element, as a rule, has a soft damping characteristic, corresponding vibrations, shocks, or the like are transmitted without influence on the force-measuring device 460. Such a spring element 456 can be chosen with the corresponding spring constants, from corresponding material, and the like depending on the requirements. Only a limited motion of the actuator element 260 is possible because of the connection with the spring element 456 and via the latter with the force-measuring device 460. Essentially the range of motion is determined by the spring element 456 and the maximum expansion, which can be evaluated by the latter. The spring element may follow a curved, for example circular, path of a moving object, and correspondingly the position of the moving object along this path can be determined. Force-measuring device 460 can include a number of electrical conducting wires, which change their resistance depending on the force exerted on them. This means, a resistance change of the electrical conducting wires corresponds to a force transferred by spring element 456, and the force is proportional to a deflection of spring element 452 and thus to a position of the longitudinal movement of actuator element 260. The wires of force-measuring device 460 are parallel to another and can be switched electrically also parallel or even in series. The wires form a resistor, which is part of a bridge circuit, as shown in Figure 18. A further resistor 462 of this bridge circuit also is formed by a number of electric conducting wires and this further electrical resistor 462 corresponds to the resistance formed by the electric conducting wires of force-measuring device 460 and is used for temperature compensation. In order to be able to determine changes in the resistance in such an electrical conductor 460 in a simple way, the electrical conductor 460 can be connected in a bridge circuit, such as a so- called Wheatstone bridge, and form at least one resistor in the bridge circuit highly accurate circuit measurements are possible by means of such a bridge, whereby a high accuracy for position determination of the actuator element 260 also results. hi order to compensate for changes in the resistance of the conductor 460, on the basis of temperature changes, so that the latter do not lead to an erroneous determination of the position of the moving object, the bridge circuit can have a further resistor analogous to the resistor formed by the force-measuring device 460. For example, if the force-measuring device 460 is made up of a number of wires, this further resistor is made in a similar way. Of course, as opposed to the force- measuring device 460, it is not exposed to a corresponding tensile force from the spring element 456. Li order to compensate for certain statistical irregularities of the wire, such as diameter deviations, changes in the properties of the material, and so forth, in a wire-like conductor 460 in a simple way, the conductor 460 can have a number of electrically conducting wires located parallel to one another. In this way, corresponding statistical deviations of the individual wires are determined and a force-measuring device 460 measuring accurately over its entire measuring range results. The wires may be individual wires or formed by an individual wire, which is laid meandering. The force-measuring device 460 has at least one electrically conducting, in particular wire- like conductor, the electric resistance of which depends on a force exerted upon it in the longitudinal direction. Such a conductor also may be made out of different materials, which are chosen, for example, with respect to the environmental conditions under which the position- monitoring sensor 295 is used. In this way the position-monitoring sensor 295 also may be used in aggressive media, under water, under pressure, under a vacuum and the like, essentially without limitations. Because of a simple structure of the position-monitoring sensor 295 there is no wear and no abrasion of the individual parts, so that the service life is extraordinarily high. Such an electrical conductor 460 as a force-measuring device changes its electrical resistance in the case of exertion of a corresponding tensile force on the conductor, and such a resistance change can be detected via corresponding stress or current changes and evaluated as a signal in the evaluating device 468. The force-measuring device 460 can be made correspondingly in order to convert the tensile force exerted by the spring element 456 into an electrical signal. A simple example of such a force-measuring device 460 can be seen if the latter has at least one electrical measuring conductor, the electrical resistance of which changes depending on a force exerted on the measuring conductor. An offset device 464 and amplifier 466 are connected with the resistors formed by the wires. Corresponding signals from the amplifier 466 may be output on an output unit of evaluating unit 468, in which case this evaluating unit 468 also can have a differentiator, by which the corresponding position values of actuator element 260 changing in time can be differentiated and thus a speed and, in a given case, acceleration, of the actuator element 260 can be determined. A zero point of the deflection of the spring element 456 can be adjusted by offset device 464. For example the springs can be pre-stressed 2% to 5%, in order to create such a measurable zero point for the motion of the actuator element 260. A stress value associated with this pre-stress is set to zero by means of the offset device 464. A voltage supply is connected with the wires and the evaluating unit for the voltage supply of the wires and evaluating device. In the case of a linear control device which has a control element moving linearly forward by a screw motion, it is advantageous if the corresponding turning of the control element is not transferred to the spring element and thus leads to a stress or force in the spring element, which is not caused by the linear motion of the control element. For this, for example, at least the connector between spring element and control element can have a rotation decoupling device. Only the linear motion of the control element is transferred to the spring element by means of this rotation decoupling element, and the rotation is received by the rotation coupling device. The spring element 456 according to Figures 15-18 is connected via connectors 470, 472 to control element 452, respectively with electrical measuring conductor 460. The connector 470 is a rotation decoupling device 468. The rotation decoupling device 468 prevents a transfer of the rotation of the operating element 452 made as a ball spindle to spring element 456. Rotation decoupling device 468 can be made, for example, by a screw which is screwed into the end of operating element 452, and which is mounted fixed capable of rotating in the connector 470, but in the longitudinal element of the spring element 456. Figure 16 corresponds to a magnified representation of section "X" from Figure 15 and Figure 17 is a magnified representation of section "Y" from Figure 15. The connection of spring element 456 with the connector 472 in particular is shown in Figure 16. This is connected to electrical measuring conductor 460, which is fastened on its end opposite spring element 456 at a fixed point of housing 474 of linear control device 476. Corresponding connecting wires are connected to the electrical measuring conductor 460 via soldering points, which lead to the bridge circuit 480, see Figure 18. In order to be able to detect corresponding resistance changes easily via associated stress changes, the electric measuring conductor 460 can be connected as a resistor in a bridge circuit, as a so-called Wheatstone bridge. According to the invention a simple electrical structure, which also requires simple means in the case of the evaluating unit 468, results from the use of the bridge circuit and the electrically conducting wires 460 as a force-measuring device. For example, an amplifier 466 and/or a differentiator and/or an evaluating device 468, connected with a microprocessor or the like, are the only electronic components, which are necessary. The differentiator may be omitted if, for example, a determination of the speed or acceleration of the actuator element 260 during this motion is omitted. In addition, arrangements of other evaluating devices are used if the latter are supported by software. The signals detected are transferred to evaluating device 468 from the bridge circuit 480 via the amplifier 466 for further processing. One branch of the bridge circuit is grounded; see "O" and the other branch lies on the plus pole of a voltage source. In operation the linear motion of the actuator element 260 can be measured as a result of the fact that a retaining force is exerted by the spring element 456 during motion of the actuator element 260. Of course this is so small that it does not hinder, or only slightly hinders the desired motion of element 260. The retaining force exerted by spring element 456 is transferred to an electrical conductor as a force-measuring device 460. The electrical conductor 460, for example, has a number of wires, the resistance value of which varies in the case of exertion of a tensile force in a longitudinal direction of the wires. The change of the resistance value is determined by a corresponding change of a voltage decreasing on the resistor, this resistance change and thus also the associative voltage, change depending on the force exerted. If the force which is exerted by the spring element 456 onto actuator element 260 is determined from the resistance changes by corresponding calculations, the deflection of the spring 456 and thus the position of actuator element 260 may be determined simply from the force if the corresponding parameter (spring constant) of spring element 456 is known. The actuator element 260 moves against the resistance of the elastically expandable retaining element 456 along an essentially linear path, having the retaining force appearing in the retaining element 456 be measured in relation to the path covered by the actuator element 260 and a signal corresponding to the retaining element 456 be transmitted from the force measuring device 460 to an evaluation device 468, and the path covered by the actuator element 260 corresponding to the retaining element 456 be determined there. The spring element 456 is expanded in the case of motion of the actuator element 260, the retaining force appearing in the spring element 456 in the simplest case is directly proportional to the path covered by the actuator element 260. The retaining force is transferred through the spring element 456 to the force measuring device 460 and measured there. A corresponding electrical signal, which corresponds to the retaining force, and thus to the path covered by the actuator element 260, is received by the evaluation device 468 connected with the force-measuring device 460. The components used for the position-monitoring sensor 295 are designed simply and economically. No wear of these components takes place, since, for example, there is no friction between the components or between the components and other objects. The position-monitoring sensor 295 is independent of a medium in which it is located, of the site conditions, of vibrations, shocks, or the like. Referring now to Figures 19-21, there is shown a dual redundant actuator 480 shown in schematically for actuating an actuation system 250. Dual redundant actuator 480 is constructed in accordance with U.S. patent application Serial No. 10/415,419, filed March 29, 2003 and entitled Actuating Device, which claims the benefit of PCT/EPOl/12551 filed October 30, 2001, which claims the priority of DE 200 18 564.0 filed October 30, 2000 (1600-08200; OTE-030327), all of which are hereby incorporated by reference herein in their entirety. The dual redundant actuator 480 includes a power assembly 290 having two separate electric motors 292a, 292b. The electric motors 292 are preferably direct current servomotors and are both used, where necessary, independently of one another for rotating the drive shaft 382. As best shown in Figures 20-21, when the drive shaft 382 is rotated, a rotating spindle 310 is displaced in the regulating direction 482 and accordingly the actuating element 260 connected to it is also displaced. The actuating element 260 is used, for example, for closing or opening a valve as control device 252, shown in Figure 9, to be actuated by the dual redundant actuator 480 of actuating system 250. The servomotors 292a, 292b may be each electrically connected to a dedicated motor control device 484 or 486. These devices 484, 486 comprise appropriately a microprocessor, a memory device and other components necessary for the control, such as controller 112. An appropriate software program for controlling the servomotors 292a, 292b is held in the motor control devices 484, 486. Each of the electric motors 292 may be individually and essentially independent of one another. Each of the motor control devices 4894, 486 can be separately connected to the dual redundant actuator 480 via suitable connections 487, 488 (see for example Figure 20). In addition, each of the motor control devices 484, 486 is connected to a suitable voltage supply, such as supply 102. In order to supply the motors 292 of the actuating device 250 with electricity also independently of one another at least two separate electrical connections 487, 488 are arranged on the housing 254 and especially on the housing cover 488 adjacent to the electric motors 292. The appropriate voltage supply as well as the data interchange or interchange of control signals can be implemented via these electrical connections 487, 488. Each of the electrical connections 487, 488 can be provided for one of the electrical motors 292, i.e. servomotors. In this connection it is also possible that each of the electrical connections 487, 488 is assigned to a stepper motor 364. A further possibility is also the provision of separate electrical connections for the stepper motors 364. According to the invention, there is the possibility that the two electric motors 292 can be controlled independently of one another for the separate drive of the drive shaft 382. In this case it is practicable to operate one of the electric motors 292 in the idling mode when the other drives the drive shaft 382. However, in order to be able to transfer a higher torque to the drive shaft 382 when necessary and therefore to displace the actuating element 260 in the regulating direction 482 with a higher force, both electric motors 292 (servomotors) can be operated simultaneously. In this case, in order to prevent the motors 292 from rotating the drive shaft 382 with a phase displacement due, for example, to different motor characteristics or due to the formation of the separate electrical supply for both motors 292 instead of providing mutual support during simultaneous operation, the servomotors 292 can be especially synchronized by software via their associated motor control devices 484, 486. A simple type of synchronization and control can be seen in that one servomotor 292 is used as the master and the other as the slave. It can be seen as being advantageous, especially for the transmission of a high torque if each of the servomotors 292 is a direct current motor. Figure 20 shows a front view of a housing cover 490 of a device housing 284, see Figure 21, of the dual redundant actuator 480 according to the invention. The housing cover 490 can also be the end of a sub housing, see Figure 21, which can be releasably connected to the rest of the housing 254. hi the housing cover 490 especially the connections 487, 488 for the electrical supply and control of the servomotors 292a, 292b are arranged. A smaller cover 492 is arranged centrally with respect to the housing cover 490, the smaller cover 492 covering a pot-shaped protrusion of the housing cover 490, see again Figure 21, in which a position sensor 295 is located. For the further monitoring of the actuating device 250 according to the invention, especially remotely from said actuating device 250, a position sensor 295 can be assigned to the drive shaft 382. With the sensor 295, it can be found, for example, how far the actuating element 260 has been regulated, whether it has returned to its initial position, etc. Figure 21 shows a section along the line PV-IV from Figure 20 with the addition of connector 488. The two servomotors 292a, 292b of the drive device 290 are arranged in the longitudinal direction 276 of the drive shaft 382 one behind the other. The drive shaft 382 extends adjacent to the position sensor 295. The sensor 295 is used to measure rotation of the drive shaft 382 and therefore for the determination of a feed of the actuating element 260 in the regulating direction 482. An especially simple and space-saving arrangement can be seen in that the electric motors 292 are arranged one behind the other in the longitudinal direction 276 of the drive shaft 382. The drive shaft 382 terminates in a transmission device 494, which, for example, can be a so-called flex-spline gearbox without classical gearwheels. A rotating sleeve 496 is rotated by the drive shaft 382 via the transmission device 494, the rotating sleeve 496 being rotationally rigidly connected to a ball nut 306 as part of a feed device 314. A further part of the feed device 314 is formed by the rotating spindle 310, which is a recirculating ball spindle. A spindle head 340 is arranged on one end of the rotating spindle 310, which protrudes from the ball nut 306. The actuating element 260 is connected to the spindle head 340 on its side opposite the rotating spindle 310. The rotating sleeve 496 is rotationally supported in the ball bearing 358 with respect to a retaining sleeve 326, which surrounds the rotating sleeve 496. The rotating sleeve 496 is inserted into a ring flange 300 at its end facing the transmission device 494. In order to prevent reactions by the control device 484, 486, which is subjected to force in the direction opposite to the regulating direction 482, via the actuating element 260 and rotating spindle 310 or recirculating ball spindle on the electric motors 292, the rotating sleeve 496 can be fixed by a first spiral spring 318 opposing a feed rotational direction on a ring flange 300 rotationally rigidly arranged in the housing 254. The feed rotational direction corresponds here to a rotation of the recirculating ball spindle for the regulation of the actuating element 260 or the rotating spindle 310 in the regulating direction 482. In order to enable resetting of the actuating element 260 in the direction opposing the regulating direction 482 despite this when the control of the actuating device 250 fails, a retaining sleeve 326 can be rotationally rigidly connected at one of its ends to the transverse wall 296, whereby the retaining sleeve 326 is rotationally rigidly connected at its other end via a second spiral spring 332 to a guide sleeve 330 in the direction opposite to the feed rotational direction, the actuating element 260 connected to the recirculating ball spindle being supported for longitudinal displacement, but rotationally rigidly in the guide sleeve 330. If this second spiral spring 332 is released during a failure of the usually provided control for the actuating device 250, the guide sleeve 330 can rotate in the direction opposite to the feed rotational direction due to the force which is transferred via the actuating element 260 and which is acting on the control device 252 to be actuated. Through this rotation the rotating spindle 310 is turned back in the recirculating ball nut 306 also in the direction opposite to the regulating direction 482 until the actuating element 260 is again arranged in its initial position. hi this connection, in order to prevent the actuating element 260 itself from being rotated in the direction opposite to the regulating direction 482 when being displaced, a spindle head 340 for mutual connection can be arranged between the actuating element 260 and the recirculating ball spindle. The actuating element 260 is decoupled with regard to rotation from the recirculating ball spindle by this spindle head 340. hi order to wind up the second spiral spring 332 for the rotationally rigid connection of the retaining sleeve 326 and guide sleeve 330 sufficiently tightly on them, the spring 332 can be drive- connected to at least one electric motor 292. A sufficiently rotationally rigid connection between the retaining sleeve 326 and the guide sleeve 330 is produced by suitable actuation of the electric motor 292 for winding up the spiral spring 332, especially before regulation of the recirculating ball spindle and actuating element 260. In order to enable appropriate guidance and retention with regard to the guide sleeve 330 as mentioned above, the spindle head 340 can comprise at least one guide element 497 protruding radially outwards, which engages a longitudinal guide 499 running in the guide sleeve 330 in the regulating direction 482. hi order to be able to still release the second spiral spring 332 with the failure of both electric motors 364, a torsion spring 366 can be arranged between the clamping sleeve 499 and ring flange 336, the torsion spring 366 being able to be tensed during the rotation of the clamping sleeve 499 for winding up the second spiral spring 332. If therefore the clamping sleeve 499 is no longer held by one of the electric motors 364 during the failure of its electrical supply in such a position in which the second spiral spring 332 is wound up, the torsion spring 366 rotates back the clamping sleeve 499 at least so far that the second spiral spring 332 is relieved for the release of the rotationally rigid connection between the retaining sleeve 326 and the guide sleeve 330. hi order to be able to finely and accurately control the rotation of the clamping sleeve 499, the first and second electric motors 364a, 364b can be stepper motors. The electric motors 292 and 364 may be powered by either DC or AC voltage, preferably DC voltage. A first spiral spring 318 is wound up on the outer sides of the ring flange 300 and the rotating sleeve 496. The spring 318 is used to provide the rotationally rigid connection of the ring flange 300 and the rotating sleeve 496 in a rotational direction opposite to the feed rotational direction of the rotating sleeve 496, i.e. the direction of rotation through which both the rotating spindle 310 and also the actuation element 260 are displaced in the regulating direction 482. The ring flange 300 protrudes essentially coaxially to the drive shaft 382, respectively rotating spindle 310 from a transverse wall 296. The wall 296 is arranged in the region of the housing 254 where it is releasably connected to the sub housing 284. A retaining sleeve 326a is rotationally rigidly connected to the transverse wall 296 radially outwards relative to the ring flange 300. The rotationally rigid connection is realized by screwing one end of the retaining sleeve 326a to the transverse wall 296. The retaining sleeve 326a extends up to its end, which faces away the transverse wall 296. The retaining sleeve 326a is rotationally supported relative to a guide sleeve 330 on this said end via a ball bearing 258. A second spiral spring 332 is wound up on the outsides of both the retaining sleeve 326a and also the guide sleeve 330. The guide sleeve 330 extends to a housing cover 334 through which the actuating element 260 is passed. The guide sleeve 330 exhibits longitudinal guides 497 running in the regulating direction 482 and in which guide elements 498 engage. The guide elements 498 protrude outwards radially from the spindle head 340. In the region of the longitudinal guides 497, the guide sleeve 330 is inserted into a ring flange 336, which protrudes from an inner side of the housing cover 334. A clamping sleeve 499 is rotationally supported by suitable bearings on an external side of the ring flange 336 and on an external side of the retaining sleeve 326. The clamping sleeve 499 is releasably connected at its end facing the drive device 290 by screwing to a toothed ring 491. The toothed ring 491 exhibits inner teeth as tooth system 493, which engages the gearwheels 362a, 362b. The gearwheel 362a can be rotated by a first electric motor 364a and the other gearwheel 362b by a second electric motor 364b. The electric motors 364 are preferably stepper motors. In order to be able to accommodate the appropriate electric motor 364 at a convenient point within the housing 254, the electric motor 364 can be drive-connected to a clamping sleeve 499 from which a dog 495 protrudes radially inwards which can be motion-connected to essentially one end of the second spiral spring 332. Due to the arrangement of the clamping sleeve 499, the electric motor 292 can be located remotely with respect to the second spiral spring 332. Here, the arrangement is preferably realized such that a space available in the housing 254 is optimally used. In order to be able to arrange the actuating device 250 suitably compact and with small outer dimensions, the clamping sleeve 499 can be rotationally supported on an external side of the retaining sleeve 326 and on an external side of a ring flange 336 which engages in the housing 254, whereby the ring flange 336 protrudes from an inner side of a housing cover 334. A simple type of drive connection between the electric motor 364a and clamping sleeve 499 can be seen in that the electric motor 364a drives a gearwheel 362, which engages teeth on especially one end of the clamping sleeve 499. In order to achieve redundancy also in connection with the drive of the clamping sleeve 499, another electric motor 364b can be arranged, especially diametrically opposed to the first electric motor 364a, through which a gearwheel 362 that meshes with the teeth can be driven. In this way the clamping sleeve 499 can be alternatively driven by the first or second electric motor 364a, 364b and especially with the failure of one electric motor the other one is used. A dog 495 protrudes radially inwards approximately centrally to the clamping sleeve 499 and the dog 495 can be coupled to one end of the second spiral spring 332, so that, depending on the rotation of the rotating sleeve 496, the second spiral spring 332 can be wound up more or less on the retaining sleeve 326 and the guide sleeve 330. A torsion spring 366 is arranged between the clamping sleeve 499 and ring flange 336. The spring 366 can be clamped between the ring flange 336 and the rotating sleeve 496 when the clamping sleeve 499 is rotated for winding up the second spiral spring 332. The following describes the function of the dual redundant actuator 480 in accordance with Figures 19-23. Since the servomotors 292a, 292b are mounted on the drive shaft 382, they can be used singly as well as in combination. Single application occurs especially when one of the servomotors 292a, 292b is to replace the other one. Common actuation of both servomotors 292a, 292b is especially then provided when a higher torque is to be transferred onto the drive shaft 382, which may amount to twice the torque, which can be transferred by one servomotor. Both servomotors 292a, 292b are connected via separate feed cable connections 487, 488, and the partially illustrated connection line 489, to their respective motor control devices 484, 486. One of the servomotors 292a, 292b, or both motors, can be actuated and controlled via these control devices and separate electrical supplies to the motor control device 484, 486 and also to the servomotors 292a, 292b. The motor control devices 484, 486 are especially formed in that one of the servomotors 292a, 292b is wired as the master and the other as the slave and synchronization of both motors to the common drive of the drive shaft 382 occurs by software. The electric motors 364a, 364b formed as stepper motors, are also arranged double in order to substitute one of the stepper motors with failure, damage or a similar condition. Also in this case, the control of the stepper motors 364a, 364b occurs independently of one another over dedicated feed cables 487, 488 and dedicated motor control devices 484, 486. Through the use of at least two electric motors 292a, 292b, it is ensured that with the failure of one motor, the other one continues to drive the drive shaft 382 in order to move the rotating spindle 310 and the actuating element 260 appropriately in the regulating direction 482. AU other parts of the actuating device 250 are present in the usual numbers and only the number of electric motors 292 is doubled. According to the invention, a second drive shaft is also not needed on which the second electric motor acts and through which it controls the rotating spindle 310 and actuating element 260. As a consequence, overall the actuating device 250 according to the invention is in its dimensions essentially unchanged with respect to the previously described actuating device 250. Alternatively, both motors 292 are used simultaneously, if, for example, a higher driving force is needed. If due to the failure of both stepper motors 364a, 364b, a release of the second spiral spring 332 is not possible, the release of the spiral spring 332 occurs through the torsion spring 366, which was tensed on winding up the second spiral spring 332 for the rotationally rigid connection of the guide sleeve 330 and retaining sleeve 326a between the clamping sleeve 499 and the ring flange 336. Otherwise the actuating device 250 according to the invention functions as follows: The ball nut 306 is rotated through the rotating sleeve 496 by rotating the drive shaft 382. Since the ball nut 306 is fixed in the axial direction relative to the housing 254, the rotating spindle 310 is displaced in the regulating direction 482 when the ball nut 306 is rotated. The actuating element 260 is also displaced at the same time as the rotating spindle 310, because the actuating element 260 is connected to the rotating spindle 310 via the spindle head 340. The displacement of the actuating element 260 can be measured via the position sensor 295. In order to obtain a bearing mechanism of high quality and high efficiency which is at the same time reversible in its movement in a simple manner, the rotating sleeve 496 can be driven by a drive shaft via a transmission device 494, the rotating sleeve 496 being rotationally rigidly connected to a ball nut 306 of a feed device 314, whereby the rotating spindle 310 formed as a recirculating ball spindle for movement in the regulating direction is rotationally supported in the ball nut 306. In this way the drive force of the electric motors 292 is transferred to the ball nut 306 via the rotating sleeve 496. The ball nut 306 rotates together with the rotating sleeve 496 and with the suitable rotation the recirculating ball spindle 310 is moved in the regulating direction 482 and consequently also the actuating element 260. It is also possible that instead of the previously described ball screw drive, a roller screw drive is analogously applied. The force applied to the actuating element 260 from the direction of the control device 484, 486, which is not illustrated, in the opposite direction to the regulating direction 482 is transferred via the first spiral spring 318 from the rotating sleeve 496 to the ring flange 300 and therefore to the housing 254. For resetting the actuating element 260 in the opposite direction to the regulating direction 382, the second spiral spring 332 is released via the dog 495, the spiral spring 332 holding the guide sleeve 330 with the retaining sleeve 326a rotationally rigid in the direction opposite to the feed rotational direction. With the second spiral spring 332 released, the guide sleeve 330 can rotate in the direction opposite the feed rotational direction, whereby the rotation onto the guide sleeve 330 is transferred via the guide elements 497 of the spindle head 340 corresponding to the reverse rotation of the rotating spindle 310. Referring now to Figure 22, there is shown another electrical device 46, namely an electrically-actuated injection valve 500 having isolation device 501 and an injection valve 502 as is described in U.S. patent application Serial No. 10/415,696, filed October 30, 2001 and entitled Isolating device which claims the benefit of PCT/EP01/12548 filed October 30, 2001, which claims the priority of DE 200 18 562.4 filed October 30, 2000 (1600-08700; OTE-030329), all of which are hereby incorporated by reference herein in their entirety. The isolation device 501 comprises a device housing 503 constructed of various interconnected sub-housings 547, 548, 549 and 550. Sub-housing 547 encloses a drive device 505 including two electric motors 509 and 510 arranged at both ends of a worm shaft 519 on which a worm 517 is provided. Sub-housing 547 may also comprise an emergency release device 526 that can be actuated by another electric motor 532. Connection 514 and a connecting line 186 connects motors 509 and 510 with remotely arranged control devices 512 and 513 or controller 112. The electric motors 509, 510, 532 maybe powered by either DC or AC voltage, preferably DC voltage. Referring now to Figure 23, a section along the line II-II of Figure 22 is shown, including the injection valve 502 with a corresponding injection valve housing 561. Injection valve 502 is attached to isolating device 501 by threaded sleeve 580 and comprises a connection line 562 providing fluid communication between a fluid pump 563 and a ball valve 586 of valve arrangement 564. An isolation stop valve 507 engages the connection line 562, such that the connection between the pump 563 and the valve arrangement 564 is interrupted. Shifting the isolation stop valve 507 out of the isolating device 501 moves slider opening 585 of the isolation stop valve 507 into connection line 562 and allows fluid communication through the connection line 562. The isolation stop valve 507 is arranged at the end of an operating element 506 that is arranged within a piston housing 571 and connected to a shaft section 572. The piston housing 571 comprises a radially extending end flange 576 that supports one end 577 of a spring arrangement 565. The other end of spring arrangement 565 is supported on sealing body 593. Spring arrangement 565 urges operating element 506 into a starting position 574, in which the end flange 576 is adjacent to a locknut 573 screwed into the sub-housing 549. Sub-housing 549 is connected to sub-housing 548, which encloses a screw 539. Screw 539 is formed of a screw nut 540, in this case a revolving roller nut, and the turning spindle 504, forming together a planetary roller screw. At its end 569 facing the operating element 506, the turning spindle 504 is inserted into a hole at the end 570 of the operating element 506 or the shaft section 572, respectively, and held therein by means of a bolt. The screw nut 540 is rotatable, but axially fixed within bearing sleeve 542. Opposite to the end 569, the turning spindle 504 projects with its other end 568 from the screw nut 540 and is there also surrounded by a section of the lower-diameter bearing sleeve 542. At the outside of this section, the bearing sleeve 542 is rotatably mounted sub-housing 548 needle bearing 544. A bearing shaft 535 passes through the bearing sleeve 542, the end 568 thereof being inserted in the end 543 of the turning spindle 504 and being stationarily held therein. In Figure 23, the turning spindle 504 is represented in its starting position 566, i.e. as far as possible inserted through the screw nut 540 in the direction away from the injection valve 502. The bearing shaft 535 is arranged in a bearing sleeve 536, which is connected to a worm wheel 518 via a spline connection. The worm wheel 518 is a globoid worm wheel and engaged with worm 517. The bearing sleeve 536 is rotatably mounted in the sub-housing 547 via needle bearings 544. The end of the sub-housing 547 that is opposite to the sub-housing 548 is detachably sealed by an end plate 559. Sub-housing 550 is detachably connected to end plate 559 and encloses positioning sensor 295. End plate 559 also includes electrical passages 567 to provide electrical connection between connection 514 and devices within sub-housing 547. A connecting line 186 connects the subsea power source 102 to electrically-actuated injection valve 500. Referring now to Figure 24, a section along the line III-III of Figure 22 and 23, respectively, is represented. The sub-housing 547 is essentially formed of a central body 553 in which a central bore 554 is formed. In this bore, the bearing sleeve 536 of Figure 23 is rotatably mounted. The worm wheel 518 is stationarily connected to the bearing sleeve 536 via the splined shaft connection 537 in the form of a ratchet. The same is engaged with its external gearing in a corresponding external gearing of the worm 517. The worm 517 is arranged on a worm shaft 519, which extends approximately tangentially to the central bore 554. Shaft ends 520, 521 of the worm shaft 519 are rotatably mounted by means of a ball bearing 533 or a roller bearing 534, respectively. An electric motor 509, 510 of the drive device 505 is associated to each of the ends 520, 521 of the worm shaft 519. The electric motor 509 is directly actively connected with the shaft end 520 or a motor shaft 522, respectively, and is detachably mounted in motor opening 555 in the central body 553. The other electric motor 505 is also detachably held in a motor opening 556. A synchronous operation of both electric motors 505, 509 can be effected with software with at least one electric motor as master and the other electric motor as slave to provide high torque and high rotational speeds that can be transmitted by the corresponding gearbox unit. One end 525 of the motor shaft 522 extends beyond the electric motor 509 along a narrowed section of the supporting sleeve 527. The motor shaft 522 extends beyond the supporting sleeve 527 into a spacing sleeve 528 that is connected to the supporting sleeve 527 via a volute spring 529 that limits the rotation of the spacing sleeve relative to the supporting sleeve to one direction. With one of its ends 530, the volute spring 529 engages a release sleeve 531, which is rotatably mounted with respect to the spacing sleeve 528 and the supporting sleeve 527. The release sleeve 531 is actively connected to a drive shaft of a stepper motor 532 that is arranged in a side housing 596 in the extension of the motor opening 555. The side housing 596 is detachably sealed by a cover 582. Referring now to Figure 25, there is shown another electrical device 46, namely a longitudinal section through a specific embodiment of a valve system 601 as described in U.S. patent application Serial No. 10/467,112 filed October 30, 2001 and entitled Valve System, which claims the benefit of PCT/EP01/12550 filed October 30, 2001, which claims priority from DE 20012168.4, filed February 8, 2001 (1600-08900; OTE-030331), all of which are hereby incorporated by reference herein in their entirety. Valve system 601 comprises a valve body 602 and a longitudinal slide 603 disposed within a valve holding recess 16 of a valve block 15. An electrochemical actuator 609 is associated with longitudinal slide 603 of the valve system 601. Electrochemical actuator 609 has a gas generator 662, that generates a gas, and, in particular, hydrogen, when an electric charge is supplied via corresponding feed lines. The electric charge is supplied by connecting lines to subsea voltage source 102. The electric supply may be either DC or AC voltage, preferably DC voltage. The generated gas generates an over-pressure in the interior of the gas generator 662 and a discharge element 658 of the actuator may be displaced in the direction of the valve block 615 via this over-pressure. The discharge element 658 is connected with the gas generator 662 via a bellows element 661. The discharge element 658 is releasably connected with a holding plate 657 at the end of the discharge element turned away from the gas generator 662. The longitudinal slide 603 is releasably attached to the middle of the holding plate 657 and is movably mounted in the housing cover 619. A connecting end 613 of the longitudinal slide 603 projects into the interior 620 of the housing 617 and there is attached to the holding plate 657. The longitudinal slide 603 extends from its connecting end 613 up to its inlet end 614 that is associated with the feed line 604 in a bottom of the valve holding recess 616. Valve block 615 has inlet channels 624, 625 and outlet channels 626, 627. Fluid communication between longitudinal bore 610 and inlet channels 624, 625 and outlet channels 626, 627 is controlled by the linear position of longitudinal slide 630. In Figure 25 the longitudinal slide 603 is shown in its outlet position, in which the feed line 604 is in fluid communication with outlet channels 626, 627 via longitudinal bore 610 and connecting lines 611, 612 of slide 603 and channels 631, 632 of central body 628. The longitudinal slide 603 is moved to a fluid feed position 653 (see the dashed line representation in Figure 25) by the electrochemical actuator 609. In the fluid feed position 653, connecting lines 611 and 612 of longitudinal slide 603 align with annular channel 646 of throttle element 637. Throttle element 637 comprises a throttle component 638 having a middle bore 639 and a guide body 640. Throttle element 637 provide fluid communication between feed line 604 and inlet channels 625, 626 via connecting lines 611, 612. Hydrogen is generated in the electrochemical actuator 609 by means of an electric charge. The discharge element 658 is discharged with the holding plate 657 in the direction of the feed line 604 by means of the corresponding over-pressure. Analogously, there is a displacement of the longitudinal slide 603 into the fluid feed position 653. A connection is made in the latter between feed line 604 via longitudinal bore 610 and connecting line 611, 612 to the inlets 605, 606 and via the latter to the inlet channels 624, 625. Hydraulic fluid is fed to the actuation device in this fluid feed position 653. Referring now to Figure 26, another electric device 46 is shown, namely a longitudinal sectional view through a rotary adjusting device 701 as described in U.S. patent application Serial No. 10/415,511, filed October 30, 2001 and entitled Rotating Regulating Device which claims the benefit of PCT/EP01/12554 filed October 30, 2001, which claims the benefit of DE 200 18 548.9 filed October 30, 2000 (1600-08300; OTE-030332), all of which are hereby incorporated by reference herein in their entirety. The rotary adjusting device 701 is designed as an installed module 707 and flange mounted to an actuator device 725. Actuator device 725 comprises at least one electromotor 743 that drives a ball screw 744, with a ball nut 746 that can be turned by the electromotor 743. Turning the ball nut 746 causes a recirculating ball spindle 745 of the ball screw 744 to be repositioned in the longitudinal direction of the actuator device 725. An operating element 724 which is connected to the recirculating ball spindle 745 is repositioned accordingly, and thus likewise a feed element 722 of the rotary adjusting device 701. The electric motor 743 may be powered by either DC or AC voltage, preferably DC voltage. A connecting line 186 may extend to connector 709, which is connected to motor 743. The feed element 722 is mounted in a longitudinal bore 723 of a rotary sleeve 704 of the rotary adjusting device 701 in such a way that it can be shifted. The rotary sleeve 704 is rotatably mounted in the interior of a bearing sleeve 705 that is removably attached to the actuator device 725. The rotary sleeve 704 is mounted so that it can rotate but cannot shift axially relative to the bearing sleeve 705. To translate the linear motion of the operating element 724 into a rotary motion of the rotary sleeve 704 relative to the bearing sleeve 705, a transmission 706 is positioned between the two as an activating device 702. The transmission 706 comprises the feed element 722, a meshing pin 717 as meshing element 716, ball or roller bearings 720, and guide slots 711, 712 in the rotary sleeve 704 as well as guide slots 713, 714 in the bearing sleeve 705. As shown in Figure 27, guide slots 713, 714 of the bearing sleeve 705 run in a straight line in the longitudinal direction 715, whereas the guide slots 711, 712 in the bearing sleeve 705 run diagonally to the longitudinal direction 715 and in particular in a spiral pattern. The meshing pin 717 engages longitudinal slots 739, 740 of a spring bearing sleeve 734 with its outermost ends 735, 736. These longitudinal slots are open in the direction of the ring flange 726 of the bearing sleeve 705. In the area of the ring flange 726 the spring bearing sleeve 734 also has a terminating flange 737, which is in contact with the ring flange 726 when the spring bearing sleeve 734 is in the end position 738 shown in Figure 26. Between the terminating flange 737 and the ring flange 730 of the closing ring 729 there is a compression spring as spring element 733. This applies pressure to the activating device 702 of the rotary adjusting device 701 counter to the adjustment direction of the operating element 724. Moving the feed element 722 in the direction of the closing ring 729 by means of the operating element 724 of the actuator device 725 causes the meshing pin 717, as the meshing element 716, to move along the guide slots 711, 724 to their ends which are toward the closing ring 729. At the same time the meshing pin 717 moves along the linear guide slots 713, 714 of the bearing sleeve 705, which is firmly connected to the actuator device 725. Because of the spiral form of the other guide slots 711, 712 of the rotary sleeve 704, when the meshing pin 717 is moved along the guide slots 713, 714 and because the meshing pin 717 at the same time engages the guide slots 711, 712, the rotary sleeve 704 is rotated by a corresponding angle. The angle of rotation then comes from the oblique path of the guide slots 711, 712 relative to the guide slots 713, 714. To support a return of the adjusting element 703 into the end position of the spring bearing sleeve 734 shown in Figures 25 and 27, there is a compression spring 733 between the ring flange 730 of the closing ring 729 and the terminating flange 737 of the spring bearing sleeve 734. The spring bearing sleeve 734 is carried along when the meshing pin 717 is moved in the direction of the closing ring 729; the ends 735, 736 of the meshing pin are in contact with ends 741, 742 of the longitudinal slots 739, 740 which are formed in the spring bearing sleeve 734. Referring now to Figure 28, there is shown another electrical device 46 namely an actuating device 801 in accordance with U.S. patent application Serial No. 10/415,418, filed September 4, 2003 and entitled Actuating Device, which claims the benefit of PCT/EP01/12549 filed October 30, 2001, which claims the priority of DE 200 18 563.2 filed October 30, 2000 (1600-08800; OTE- 030328), all of which are hereby incorporated by reference herein in their entirety. Actuating device 801 is shown enclosed in a device housing 803 that is connected to a throttle device 802 including a throttle housing 851 having a fluid inlet 859 and fluid outlet 860. Electrical connector 813 connects actuating device 801 to the remotely disposed control and actuation assembly 80 by means of electrical connecting lines 186 for supplying power to electric motors 508, 509 powered by either DC or AC voltage, preferably DC voltage. Throttle device 802 further comprises a throttle space 858 that is located between the fluid inlet 859 and the fluid outlet 860 and. contains a passage sleeve 863 having a number of passage openings 885 therethrough. Opposite the fluid outlet 860 extends a throttle element bore 857 in the throttle housing 851, in which a throttle element 862 is mounted so as to be displaceable in an axial direction. Throttle element 862 includes throttle sleeve 864 that is axially disposable between a position covering passage opening 885 and a position not covering passage openings, so as to control the flow of fluid between fluid inlet 859 and fluid outlet 860. The axial displacement of throttle element 862 is controlled by actuating element 806. Actuating element 806 is connected to a turning spindle 804 that is displaced by rotating a thread nut 825 in which the turning spindle is rotatably mounted as recirculating ball screw or recirculating roller spindle. The turning spindle 804 and the thread nut 825 (ball nut or roller nut) form a part of a transmission device 807, via which the actuating element 806 is functionally connected for adjustment purposes. The thread nut 825 is held in a bearing sleeve 826 in manner secured against rotation and is rotatable via the axial bearing 829. At one end 827 of the thread nut 825 facing the actuating element 806, an outer toothing 828 is arranged, which is formed by a worm gear 817 forms part of a worm gear pair 815 and engages with its toothing 828 a corresponding outer toothing of a worm 816 as additional part of the worm gear pair 815 (also see Figure 29). The worm gear 817 in the exemplary embodiment according to the invention is formed by a globoid worm wheel, the outer toothing of which is engaged by a corresponding outer toothing of a cylindrical worm 816. The worm 816 is arranged as an additional part of the worm gear pair 815 on a woπn shaft 818. The worm 816 and the worm gear 817 form a transmission unit 810 as part of the transmission device 807 whereby such transmission unit 810 forms a self-locking transmission unit. By means of its two shaft ends 819, 820 the worm shaft 818 is releasably connected with electric motors 808, 809 forming a drive device 805 of the actuating device 801. The electric motors 808, 809 are servomotors, especially direct current servomotors. Thus, the actuating device 801 comprises an electric drive device formed by two servomotors 808, 809. Such servomotors 808, 809 are remotely controllable via corresponding connecting lines and their control devices 811, 812. When actuating one motor or both motors in synchronous operation, such motors drive the worm shaft 818 and thus the worm 816. Such worm 816 is engaged with the appertaining worm gear 817. The worm and the worm gear form a self- locking worm gear pair being locked at least oppositely to the feed direction of the turning spindle 804 in the direction of the throttle device. The self-locking state of the worm gear pair can only be released by applying a release torque from the servomotors 808, 809. Especially in interaction with the roller thread as additional part of the transmission device 807, the worm gear pair easily results in a high gearing and allows the transmission of a high torque. The gearing can be selected, according to desire, by correspondingly selecting the worm, worm gear, thread nut and turning spindle. When the thread nut 825 directly connected with the worm gear in a manner secured against rotation is rotated, the turning spindle 804 is correspondingly extended in the direction of the actuating device or is retracted in the opposite direction. Connected with the turning spindle 804 is the actuating element 806 at the free end of which a corresponding throttle element is disposed. The actuating element with the throttle element engage the throttle housing adjacent to the actuating device 801, where they serve to vary the fluid passage between the fluid inlet and the fluid outlet. Referring now to Figure 30, there is shown still another electrical device 46 namely an actuating device for a subsea valve in accordance with German patent application No. DE 203 11 033 filed July 17, 2003 and entitled Pump Device, hereby incorporated herein by reference. In Figure 30 a longitudinal section through one embodiment of an inventive pump device 901 is illustrated. Pump device 901 includes electrically operated driving device 905, which is made up of a rotatable but axially non-movable mounted spindle nut 910 and an axially movable, but non- rotating threaded spindle 911. Spindle nut 010 is fixed to rotary socket 915 that is rotatably mounted inside a pump housing 935 by means of a set of angular roller bearings. The rotary socket 915 is connected to a harmonic transmission 913 that is driven by gear 919. Gear 919 engages gear 920 that is rigidly arranged on a drive shaft 921 that is turned by two electric motors 909 in the form of a synchronous or asynchronous motors. The electric motors 909 may be powered by either DC or AC voltage, preferably DC voltage. Operating motors 909 turn gear 920, which engages and rotates gear 919 and rotary socket 915 through harmonic transmission 913. The rotation of rotary socket 915 also rotates spindle nut 910, which causes axial translation of threaded spindle 911. Position sensor 295 may monitor the axial position of threaded spindle 911. A connector 907 connects the electric motors 909 with connecting lines 186 extending to a subsea power source 102. The threaded spindle 911 is detachably connected to piston 961, which is mounted so as to be able to move axially within piston space 923 of piston cylinder unit 903. Piston space 923 has a cylinder base plate 930, in which an intake hole 926 and a discharge hole 927 are formed substantially parallel to one another. A non-return valve 928, which is spring-biased in the direction of the intake hole 926 is arranged on the side of the piston space 923 in front of the intake hole 926, similarly a non-return valve 929 which is spring-biased in the direction of the piston 961 is arranged on the side of the piston space 923 in front of the discharge hole 927. If piston 961 moves to the left, the non-return valve 928 is opened by corresponding negative pressure in the piston space 923 and hydraulic fluid 904 enters the piston space 923 through the intake hole 926. If piston 961 moves to the right, the hydraulic fluid present in the piston space 923 is forced through the open non-return valve 929 into the discharge hole 927. The intake hole 926 leads to a buffer tank 931, which substantially surrounds the cylinder base plate 930 and serves to store hydraulic fluid, which can be fed through a supply line 933. The supply line 933 may be connected to a hydraulic fluid supply line 958 by a snap-coupling mechanism 957. This snap-coupling mechanism 957 likewise serves to connect a discharge pipe 934, which extends from the discharge hole 927 through the buffer tank 931, and which is then led further in the direction of the valve 902. The discharge pipe 934 has at least one branch feeder pipe 936 on its section running between the snap-coupling mechanism 957 and the valve 902, to which an accumulator 937 as pressure storage means for hydraulic fluid is attached. In the case of one embodiment this accumulator contains a number of Belleville springs 938, which are stacked in parallel and/or in series. The accumulator 937 works as pressure storage means due to the arrangement of the Belleville springs 938. By suitable dimensioning of the accumulator, valve and actual pump this can operate maintenance-free over a long period whereby due to the provision of the accumulator the pump can be intermittently operated. As an example, assume a required pressure of approximately one kbar for valve 902. Pump device 901 is operable to generate a fluid pressure of 1.4 kbar. Therefore, accumulator 937 maintains hydraulic fluid at approximately 1.4 kbar. Thus, pump device 901 does not need to be operated until the pressure loss in the accumulator amounts to more than approximately 0.4 kbar. Only when the pressure drops to a value of less than l.Okbar will the pump begin to work again and recharge the accumulator. In some embodiments, a safety relief valve 942 e.g., a subsurface safety valve, is provided to prevent pressure within pump device 901 from exceeding a pre-set limit. In the vicinity of the buffer tank 931 and/or the cylinder base plate 930 a first branch pipe 939 and a second branch pipe 940 branch off from the discharge pipe 934 and/or the discharge hole 927. The first branch pipe 939 extends as far as a pressure switch 941, which, depending on the pressure of the hydraulic fluid, transmits an electrical signal to an actuator 944. Actuator 944, as for example a step motor, has a drive shaft, at one end of which a pinion 945 is arranged, that engages with a cam disk 946, which is rotatably mounted by means of roller bearings 965 on an outer periphery 956 of the rotary socket 915. The cam disk 946 has gearing assigned to the pinion 945 as well as at least one control cam 948 with a control tappet 947 of a safety relief valve 942. The safety relief valve 942 is designed as mechanically controllable non-return valve 943. Safety relief valve 942 is opened by control tappet 947 if roller 950 runs onto the control cam 948. Opening valve 942 allows fluid communication between second branch pipe 940 and return line 955, which leads to buffer tank 931. As a result no discharge to the environment takes place and equally there is no corresponding contamination or also feedback to a far away place as for example from the sea bed to the sea surface. A reverse rotation device 952, such as a clockwork-similar coil or spiral spring 953, is assigned to the actuator 944. The reverse rotation device 952 is arranged such that in the event of failure of the actuator 944 and with the safety valve 942 open, the cam disk 946 is automatically turned back by the tension of the coil/spiral spring so that closure of the safety valve 942 is ensured both by the spring-bias of the valve element in the direction of the closed position and also in particular by the reverse torque of the coil/spiral spring as reverse rotation device 952. Referring now to Figure 31, there is shown another embodiment of the present invention. An electrically controlled subsea production system 1000 includes a surface platform 1010 and one or more subsea trees 1020. Surface platform 1010 corresponds to the first location 42 as shown and described in reference to Figure l(c) and subsea trees 1020 correspond to the remote location 50 as shown and described in reference to Figure l(c). Subsea trees 1020 include electric control pods 1080 connected via electrical conductors 1050 from a subsea electrical distribution skid 1030 that is electrically coupled to surface platform 1010 via electrical control umbilical 1040, e.g., umbilical 68. Subsea trees 1020 also include production outlets 1090 that send production fluids through conduits 1060 and production riser 1070 to surface platform 1010. Subsea trees 1020 are preferably operated with only electrical control inputs from surface platform 1010 operating electrical devices 46, such as actuators, on the trees but may also include hydraulic and electro-hydraulic control systems when desired. Referring now to Figure 32, a schematic representation of some of the surface mounted components of production system 1000 are shown. Master control station 1100 includes a channel A 1102 and channel B 1104, each generated by a surface communication control unit 1106, 1108, W
respectively. Master control station 1100 communicates through connections 1110 and 1112, e.g. controller 76, with the platform control system and through hardwired and optically isolated interfaces with a high voltage converter 1120, e.g., converter 72. High voltage converter 1120 draws dual three-phase electrical power from platform uninterruptible power supply 1114, e.g., 78, and supplies isolated DC supply power to at least four conductors 1122, 1124, 1126, and 1128 within an electrical umbilical 1040, e.g., umbilical 68. Umbilical 1040 is connected to a mechanical hang off 1132 disposed on platform 1010. Electrical umbilical 1040 umbilical carries electrical power and communication from platform 1010 to electrical distribution skid 1030. Umbilical 1040 may comprise at least eight high voltage coaxial cables that are manufactured in one continuous length. Referring now to Figure 33, umbilical 1040 terminates in connector 1236 that interfaces with electrical umbilical termination 1238. Electrical umbilical termination 1238 includes a plurality of pig-tail conductors 1240 that connect each of the electrical conductors in umbilical 1040 with electrical distribution skid 1030. Electrical distribution skid 1030 comprises a plurality of high voltage converters (bullnoses) 1250, e.g., converter 86 with converter components 122, to convert the high voltage (3,000 to 6,000VDC) supply from the surface down to 300 VDC to power subsea trees 1020 and to decouple the communications from the DC power. Bullnoses 1250 are preferably a modular construction sized to accommodate sufficient electronic units to step down the power and work to precisely control the voltage supplied to the subsea trees 1020 by diverting surplus power. A bullnose 1250 is provided for each electrical conduit from umbilical 1040. Mounting bases 1252 for additional bullnoses may also be provided for expansion. Pig-tail conductors 1240 provide inputs to bullnoses 1250, which convert the high voltage from umbilical 1040 to lower voltage current. This lower voltage current is then passed along electrical jumpers 1254 to electric control pods 1080 mounted on subsea trees 1020. Electrical jumpers 1254 from the electrical distribution skid 1030 carry the 300VDC supply for the subsea frees 1020 and a screened communications cable to provide instructions to control pods 1080. The ends of each electrical jumper 1254 are terminated with a multi-pin ROV wet mate connector. Electric control pods 1080 serve two functions. Firstly, it controls the various functions on the subsea tree, and secondly, it acquires data from the free and the subsea instrumentation for transmission to the surface. Control pods 1080 are preferably lightweight units of a universal design and are configured to serve the functional requirements of subsea frees 1020. Control pods 1080 are preferably free mounted and can be installed and retrieved using standard ROVs or remotely operated running tool. Electrical connections between the control pods 1080 and subsea frees 1020 are made remotely using wet-mate electrical connectors through a pod mounting base. A subsea electronic module is housed within each control pod 1080, e.g. controller 112, and is used to effect all electronic communication and to monitor internal and external pod field sensors. The subsea electronic module also controls the operation of the actuated valves on subsea tree 1020 upon receipt of a command signal from master control station 1100 (see Figure 32). Figure 34 shows a schematic view of a subsea tree assembly 1020 including a tree, 1310 landed on wellhead connector 1300 of subsea wellhead 1302. The tree may be a spool tree, dual bore tree or other type of tree having subsea devices. Tree 1310 is a spool tree. A sealing sleeve 1304 is shown extending between wellhead 1302 and a counterbore in the lower end of the tree 1310. Tubing hanger 1306 is supported within tree 1310 and has a lateral production port 1308 aligned with a lateral production port 1312 in tree 1310, the flow through which is controlled by production master valve 1314. An external flow line 1316 is shown extending from production master valve 1314 to a production wing valve 1318 and a production choke valve 1320. Line 1322 extends from flow line 1316 and connects to a production isolation valve 1324 and a test isolation valve 1326. Flow through flow line 1316 connects to production outlets 1090 (see Figure 31). The tubing hanger 1306 suspends tubing 1328 down through wellhead 1302 and into the cased borehole. A surface controlled subsea safety valve 1330 and a downhole pressure and temperature transducer 1332 are disposed in the lower end of production tubing 1328. A control line 1334 extends through the spool tree 1310 and out the side of tubing hanger 1306 to control the downhole safety valve 1330. Likewise, an electrical line 1336 extends downhole to the pressure and temperature transducer 1332 to transmit signals from the transducer. The downhole safety valve 1330 is preferably electrically controlled as previously described. An annulus passageway 1338 extends from the production tubing annulus and into a annulus passageway 1342 in the body of spool tree 1310. An annulus master valve 1344 controls flow through annulus passageway 1342. Workover passageway 1346 communicates with the annulus passageway 1342 and extends upwardly through the wall of spool tree 1310 to an opening in the interior wall of the spool tree 1310 to provide communication with the spool tree bore 1348 above tubing hanger 1306. A workover valve 1350 controls flow through the workover passageway 1346. A cross over line 1352 communicates between passageway 1354 flow line 1316. A cross over valve 1356 controls the flow therethrough. An annulus wing valve 1358 and a gas lift choke valve 1360 are disposed in passageway 1354. In the preferred embodiments, each of the valves used in subsea tree assembly 1020 utilize electrical actuators that are powered and controlled by master control station 1100 via electrical umbilical 1040 and electric control pods 1080. The motors used by the electrical devices 46 are preferably powered by DC voltage. By eliminating hydraulically actuated valves, control and operation of subsea tree assembly 1020 is all electrically controlled. In summary, the electric system offers many advantages, such as quick response, elimination of hydraulic fluid, no dumping of fluid to sea (environmentally friendly), and the ability to perform real time diagnostics on the actuators, valves, and chokes. At the surface, the requirement for a hydraulic power unit is eliminated and the surface equipment can be packaged more compactly. It is preferred that the subsea wellhead assembly include a subsea tree having all electrically actuated actuators. It is further preferred that the electrically actuated actuators have DC motors whereby the subsea DC voltage source supplies DC voltage to the DC motors. The subsea DC voltage source receives a high DC voltage from a voltage supply and control assembly at the surface via an umbilical and a plurality of subsea voltage converters convert the high DC voltage to a low DC voltage for supplying the electrically actuated actuators. Preferably all actuators disposed on the tree are electrically actuated actuators. The embodiments set forth herein are merely illustrative and do not limit the scope of the invention or the details therein. It will be appreciated that many other modifications and improvements to the disclosure herein may be made without departing from the scope of the invention or the inventive concepts herein disclosed. Because many varying and different embodiments may be made within the scope of the present inventive concept, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.