The invention relates to a gas-insulated medium voltage switchgear with a circuit breaker pole part arrangement in a gastight compartment of the switchgear, and with a drive arrangement for switching actuation of the circuit breaker, wherein the drive as well as the pole part arrangement is fixed on a common plate or frame, which is provided with a gastight sealing, and is closing the aforesaid compartment gastightly in such, that in the completely mounted position of the plate or frame, the pole parts are positioned inside, and the drive is positioned outside the aforesaid gastight compartment, according to the preamble of claim 1 .

In general, that means in the state of the art, such medium voltage vacuum circuit breakers mainly consist of a drive mechanism and electric poles. Vacuum interrupters are installed within the poles. The drive is connected to the vacuum interrupters via pushrods which actuates the mechanical movement of the switching contacts inside the vacuum interrupters. The poles provide the mechanical support to the vacuum interrupters, and are fixed to the circuit breaker structure and therewith to the gas-insulated switchgear panel.

The pole-design has to withstand the dielectric, thermal and mechanical stress during service and testing conditions. In respect of dielectric stress the insulation parts of electric poles must provide sufficient electric creepage distance on electrically stressed paths and sufficient high electric resistivity. Furthermore the design should avoid thin gas gaps between insulating and electrically stressed parts where an accumulation of the electric field appears. The poles have to be arranged inside the switchgear in a way that sufficient electric clearance is provided between the poles and earthed parts of the switchgear and between the poles in multiphase systems.

In respect of thermal stress the insulating parts of electric poles must withstand the ambient temperature in the circuit breaker compartment and the

temperature of conducting parts with which they are in contact. Mechanical and dielectrical properties of the insulating parts of the poles must not change inappropriately.

In respect of mechanical stress, the pole design and especially the

mechanically supporting parts of the poles must withstand the mechanical stress during switching of the circuit breaker and the electromagnetic forces during fault current.

In general the electric poles of medium voltage circuit breakers are arranged in parallel to each other. The mechanical stress caused by electromagnetic forces on parallel poles in a switchgear which is subject to fault current is directly proportional to the square of the fault current and indirect proportional to the pole distance.

The electric field and therewith the dielectric withstand of the gas volume between parallel poles depend indirectly on the pole-distance.

Furthermore the pole distance depends on the width of the poles, the width of the interrupting units inside the poles, on the switchgear in which the circuit breaker will be installed, the drive mechanism of the circuit breaker, etc. As a consequence different ratings and designs of switchgears require different pole distances of the circuit breakers. In general circuit breakers with different pole distances comprise different drives which are specially designed for the corresponding pole-distance.

Known constructions lead to the following disadvantages.

- High variance/ number of parts and subassemblies

- Preproduction of subassemblies not meaningful due to low needed volume per year of each part

- Long production time

- High production costs

- Low quantities per part and year

- High effort on product design maintenance due to high number of parts and bill of materials

- Outsourcing of circuit breaker subassemblies difficult

- Each rating requires characteristic design

- No interchangeability of parts of different circuit breakers

So it is the object of the invention, to overcome the aforesaid disadvantages by constructural features, which may coincidently lead to further advantages in a method of assembling such a medium voltage vacuum circuit breaker for gas- insulated switchgear.

According to a medium voltage vacuum circuit breaker for gas-insulated switchgear this is solved by the invention of the feature combination of claim 1 .

Further advantageous embodiments are disclosed in the depending

claims 2 to 7. According to a method for manufacturing or assembling of such a medium voltage vacuum circuit breaker for gas-insulated switchgear, the invention is based on the features of claim 8.

Constructural basical features for the use of the invention are, that a

standarized circuit breaker drive is adaptable to switchgear arrangements with different pole distances, and that the plate or frame is provided with holes, in which gastight mechanical feedtroughs are arranged in, through which the drive is coupled with each of the vacuum interrupters in the pole parts, and that by predefinable positioning of the holes, the plate or frame can easily be adapted to the pole distance in the gastight compartment. So the drive itself, which is located outside the gastight compartment, can be mounted independently from the arranged elements inside the gastight compartment. Also the maintanance service of the drive can be handled from outside the gastight compartment without the need of opening it.

Key feature of the invention in this context is, that a standardized circuit breaker drive can be used or can be easily adapted to switchgear arrangements with different pole-distances.

Aditionally to that, the invention is, that the plate or frame is provided with holes, in which gastight mechanical feedtroughs are arranged in, through which the drive is coupled with each of the vacuum interrupters in the pole parts, and that by predefinable positioning of the holes, the plate or frame can easily be adapted to the pole distance in the gastight compartment. Important is, that standardized and same drives can be used in different arrangements with different pole distances.

A further important and advantageous embodiment is, that for a three phase arrangement of circuit breaker pole parts in one gastight compartment, the drive is coupled with one common main shaft, which transforms a rotational movement of the spring drive into a linear movement for each vacuum

interrupter in such, that via a curve disc the rotational movement of the main shaft will be transformed into a linear movement of a movable contact of the vacuum interrupter by three pairs of levers, and that the adaption to a

predefined pole part distance is realized only by exchange of the common shaft and the coupling shaft, adapted to the desired pole distance.

In a further advantageous embodiment, the drive is a spring drive.

The plate or frame is provided with gastight mechanical feedtrough or feedtroughs, through which the drive is coupled with the vacuum interrupter in the pole part. This leads to the above already mentioned advantages.

In a further advantageous embodiment, said levers are coupled by means of coupling rod which is moved by the levers in perpendicular direction to the axis of the rod.

A further important embodiment is given by predefinable positioning of the holes of the mechanical feedtroughs in the plate or frame, the plate or frame can easily be adapted to the pole distance in the gastight compartment, so that the drive can be adapted to the used pole-distance.

A further advantageous embodiment is, that the pole parts each consist of a pair of half shells, which will be assembled together, with the vacuum interrupter between the half shells.

In a further advantageous embodiment, the already aforesaid advantage can be caused in that the coupling rod is via its choosen length adapted to the pole distance, used in the switchgear.

A further and final important advantageous embodiment is, that the aforesaid elements are sampled on modules in such, that the spring of the drive and/or that a motor for charging the spring is arrangend on a separateable charging module and/or that the movement transmission elements, and/or that means mechanical transmission elements like the levers and the curve discs are arrangend on a separateable transmission module, and/or that finally latching elements are arrangend on a latching module.

The assembling can be done stepwise by connecting fully premanufactured modules in such, that also an adaption to different pole distances is not disturbed, but supported by the module construction.

The plate or frame with other feedtrough distances has to be exchanged, in cases of adapting to other pole distances. With that, the position of the curve discs and levers in main shaft and the coupling rod length has to be adapted.

An embodiment of the invention is shown in the drawing.

Figure 1 : Embodiment with a pole distance x

Figure 2: Embodiment with a pole distance y, different from x

A drive and a mechanical adaptable system for medium voltage vacuum interrupters for gas-insulated switchgear is shown in figure 1 , and for a different pole distance in figure 2, which is able to drive the movable contacts inside the vacuum interrupters, also in use of switchgear arrangements with different pole- distances. The concerning drive 8 is based on a spring drive mechanism. The drive 8 is mounted on a stiff aluminum plate 2 which is fixed to the switchgear panel. The fixation of said aluminum plate to the panel is gastight, and not further detailed shown in the figures. The electric pole parts 1 of the circuit breaker are fixed on the opposite side of the drive 8 on the aluminum plate 2. The driving force from the circuit breaker drive 8 to the poles 1 , or better saying, to the movable contacts of the interrupters inside the pole parts, is transmitted by push rods 9 through gastight mechanical feedthroughs 3 in the aluminum plate 2. The distance between the feed throughs 3 depend on the pole-distance of the circuit breaker.

Within the aforesaid invention, related drive curve discs 7 are fixed on the right hand end, middle and left hand end of the rotating main shaft of the circuit breaker. Said curve discs transform the rotating motion of the main shaft 6 into a linear movement of three pairs of levers 5. Said levers 5 are coupled by means of a coupling rod 4, which is moved by the levers 5 in perpendicular direction to the axis of the rod. Said coupling rod comprises holes to which the drive rods of the poles of the circuit breaker are installed. The distance in between the holes and the aforesaid feedtroughs 3 is chosen according to the pole-distance x for which the drive is applicable. Thus one drive is applicable to circuit breakers of different ratings with different pole-distances by simply using different coupling rods with different distances between the holes in the rods. Thus all parts of the drive 8, except the coupling rod 4 are identical for different pole-distances x, y.

A special embodiment is where the drive 8 is installed in a circuit breaker with vacuum interrupter, where the poles are comprising the half shells, and consist of a vacuum interrupter, push rods, connecting parts etc, like it is shown for different pole-distances in figures 1 and 2.

A further embodiment is where the length of the coupling rod depends on the pole-distance of the circuit breaker.

A further embodiment is where the drive is realized in a modular way i.e.

consisting of e.g. an energy storage and charging module, a transmission module, a latching module etc..

A further embodiment is that the pole-distance measures 120mm, 150mm or 210mm respectively. Numbering

1 pole parts

2 plate or frame

3 gastight mechanical feedtrough

4 coupling rod

5 lever

6 main shaft

7 curve disc

8 drive

9 push or drive rod x,y pole distances