Background of the invention

[0001] The invention relates to a joint system for sealing elements, in particular for joining the ends of a sealing element.

[0002] Specifically but not exclusively, the invention may be used to join the ends of a sealing ring of a rotating shaft, for example the support shaft of a turbine of a wind power plant. The invention may nevertheless also be used to join seals in other sectors or applications, such as, for example, in cement works, tobacco shredders, full section mechanical mills (tunnel boring machines), etc. The invention may, moreover, be advantageously used to join sealing elements of various types, like for example elastomers of large diameters, static seals (OR), etc. The sealing element may be configured, in particular, for a radial, frontal or yet other type of seal. The sealing element may act, in particular, as a seal between two machine elements that are reciprocally movable with a rotational movement or reciprocal movement.

[0003] In the wind power sector, the need for maintenance (often emergency maintenance) is becoming necessary on wind power plants that were installed more than twenty years ago, in particular replacing parts subject to wear and tear. One of the most critical elements is the sealing ring that operates on the shaft of the turbine.

[0004] In these cases it is known to install the sealing ring by cold joining of the two end portions of the ring by gluing, generally with epoxy glues. The known joining systems of the sealing ring nevertheless have the drawback that the glues used remain stiff and/or undergo alterations that are different from those of the elastomeric material of the sealing ring, with consequent poor elasticity of the seal, weakening of the ring and reduced durability of the operating life thereof.

Summary of the invention

[0005] One object of the invention is to make a joint system for rings or sealing systems that is able to overcome the aforesaid drawback of the prior art.

[0006] One advantage is to provide a joint system in situ that enables the ends of a ring or sealing system to be joined simply and rapidly.

[0007] One advantage is to increase the average operating life of the sealing ring, element or system.

[0008] One advantage is to improve the quality of the joint of the sealing ring, element or system. [0009] One advantage is to join the ends of a sealing ring, element or system without compromising the elasticity thereof.

[0010] One advantage is to provide a joint system that is assemblable in situ that is constructionally simple and cheap.

[0011] One advantage is to make available a system for hot joining of sealing rings, elements or systems that is of universal type, extremely versatile and easily adaptable for use with any type of sealing member.

[0012] One advantage is the possibility of inserting the joint system inside a window of accessibility of a machine, for example of a turbine of a wind power plant; in particular, the joint system may be designed (for example with tilted plane/s and locking system on the accessibility window) in order to be able to work practically and easily in the best of ways.

[0013] One advantage is to have a joint system that is particularly compact, handy and easy to handle and transport (for example insertable into a backpack), that may be used, in particular, with considerable practicality of use, in the most inconvenient and hard to access maintenance tasks, for example to fit a washer, typically in the accessibility windows of wind-power turbines.

[0014] Such objects and advantages, and still others, are achieved by the joint system according to one or more of the claims set out below.

[0015] In this description, for the sake of simplicity, the joint of a sealing ring is discussed, although the joint could be any other type of element, body, member or sealing system that is able to be joined.

[0016] In one embodiment, a universal joint system, for hot joining ends of a sealing element (for a rotating shaft of a machine), is decomposable and assemblable in situ to form a mould (injection and/or compression mould) that defines a moulding cavity of a joint portion interposed between two end portions of the element retained by two respective pairs of half shells.

[0017] In one embodiment, a universal joint system for hot joining of the two opposite ends of a sealing ring or element or body or system (in particular for sealing at least one movable component - for example rotating or with reciprocal movement - of a machine), comprises first gripping means for gripping a first end portion of a sealing ring, second gripping means for gripping a second end portion of a sealing ring, housing means for receiving (removably manually by an operator) the first and the second gripping means so that the two end portions are brought up together to a reciprocal distance, mould means for defining a moulding cavity interposed between the first and the second gripping means for moulding a joint portion that joins together the first and the second end portion. It is possible to provide means for hot injection and positioning of a dose of material for seals inside the moulding cavity. The joint system is decomposable and assemblable in situ.

Brief description of the drawings

[0018] The invention may be better understood and implemented with reference to the attached drawings that illustrate some embodiments thereof by way of non-limiting example.

[0019] Figure 1 is a section according to plane I-I of figure 3 of a first embodiment of a joint system made according to the present invention.

[0020] Figure 2 is the section according to plane II- II of figure 1.

[0021] Figure 3 is the section according to plane III- III of figure 1.

[0022] Figure 4 is the section according to plane IV-IV of figure 1.

[0023] Figure 5 is the section according to plane V-V of figure 1.

[0024] Figure 6 is a section of a second embodiment of a joint system made according to the present invention.

[0025] Figure 7 is the section according to plane VII- VII of figure 6.

[0026] Figure 8 is a section according to plane VIII- VIII of figure 10 of a third embodiment of a joint system made according to the present invention.

[0027] Figure 9 is the section according to plane IX-IX of figure 8.

[0028] Figure 10 is the section according to plane X-X of figure 8.

[0029] Figure 11 is the section according to plane XI-XI of figure 8.

[0030] Figure 12 is the section according to plane XII- XII of figure 8.

[0031] Figure 13 shows a diagram of one embodiment of a power panel that is usable for driving and controlling a joint system according to the invention.

Detailed description

[0032] For the sake of simplicity, analogous elements of different embodiments are indicated by the same numbering.

[0033] With reference to figures 1 to 5, with 1 overall a joint system has been indicated for a sealing element of a movable part of a machine, in particular for joining the ends of a sealing ring R to be installed on a rotating element of a machine, for example the sealing ring of the support shaft of a turbine of a wind power plant. [0034] The joint system 1 may comprise, in particular, first gripping means 2 for gripping a first end portion of an open sealing ring R. The first gripping means 2 may comprise, in particular, at least a first pair of half shells configured for being inserted into and removed manually by an operator within a first seat of housing means 3 of the system.

[0035] The first pair of half shells may be closed with removable closing means, for example with screw fixing means 4. It is possible to provide, additionally or alternatively, for the use of other types of closing means, for example clamping means or vise means, in particular rapid clamping means provided with a toggle mechanism with a clamping lever that is drivable with a control lever. The first pair of half shells may define, as in this embodiment, in a closing position, a first cavity 5 (figure 5) that may receive, for example in a shapingly coupled manner, the first end portion of the sealing ring R.

[0036] The system 1 may comprise, in particular, second gripping means 6 to take a second end portion of the sealing ring R.

[0037] The two end portions of the ring R are intended to be (hot) joined by the joint system 1.

[0038] The second gripping means 6 may comprise, in particular, at least one second pair of half shells configured for being inserted into and removed manually by an operator within a second seat of the housing means 3.

[0039] The second pair of half shells may be closed with removable closing means, for example with screw fixing means 7. It is possible to provide, additionally or alternatively, for the use of other types of closing means, for example clamping means or vise means, in particular rapid clamping means provided with a toggle mechanism with a clamping lever that is drivable with a control lever. The second pair of half shells may define, as in this embodiment, in a closing position, a second cavity 8 (figure 4) that may house, for example in a shapingly coupled manner, the second end portion of the sealing ring R.

[0040] As said, the system 1 may comprise, in particular, the housing means 3 for receiving (within the respective seats) the first gripping means 2 and the second gripping means 6, in such a manner that the two end portions of the ring R are brought to within a preset distance of one another.

[0041] The housing means 3 may have, as in this specific embodiment, two opposite openings for the passage of the sealing ring R taken, on one side, by the first gripping means 2 and, on the opposite side, by the second gripping means 6. The housing means 3 may comprise, as in the embodiment disclosed here, one or more containing walls that may define the first seat and/or the second seat to receive, respectively, the first and the second pair of half shells 2 and 6 that retain in position the opposite end portions of the ring R.

[0042] The system 1 may comprise, in particular, mould means arranged at least partially in the distance between the first gripping means 2 and the second gripping means 6 to define a moulding cavity 9 for moulding a joint portion that joins together the first end portion and the second end portion of the ring R.

[0043] The mould means may comprise, as in this embodiment, a first (lower) half mould 10 and a second (upper) half mould 11 that are movable in relation to one another with the possibility of adopting at least one closing position (see attached figures), in which they define the moulding cavity 9, and at least one open position (not shown), in which the mould means may be removed, so that the sealing ring R, with the joint (which connects the ends and completes the ring by shutting the ring) moulded in situ, is free to operate to seal the rotating element on which it is installed.

[0044] The second half mould 11 may be, in particular, slidable on guide means 12 that may be, as in this embodiment, fixed to the first half mould 10.

[0045] The guide means 12 may comprise, as in the specific embodiment disclosed here, two or more sliding bars. Each sliding bar may have, in particular, a proximal end fixed to the first half mould 10 and a distal end fixed to a body 13, in particular a flange body.

[0046] The system 1 may comprise, in particular, injection means for hot injection moulding of a dose of (elastomer) material for seals inside the moulding cavity 9. The injection means may comprise, as in this embodiment, piston means 14 having at least one slidable portion within a variable volume chamber 15 defined at least in part by the mould means.

[0047] The variable volume chamber 15 may be connected to the moulding cavity 9, as in this embodiment, through one or more flow channels 16.

[0048] The variable volume chamber 15 may be arranged, in particular, for receiving a dose of (elastomer) material for seals (for example in solid format), intended for being (first melted in pasty state by heating and then) injected into the cavity 9 by the hot injection means.

[0049] In particular, an injection movement of the piston means 14 (a movement that reduces the volume of the variable volume chamber 15) may be driven by (screw) thrusting means 17, as in this embodiment. This thrusting means 17 may have, in particular, at least one first end in contact with the piston means 14 and at least one second end 18 arranged for the removable connection to a motor-driven portable tool (which is not shown, for example of known type), for example a portable drill, outside the joint system 1.

[0050] The driving means may comprise, additionally or alternatively to the thrusting means 17, pressure means or pump means that is for example fluid-driven (hydraulic or pneumatic pump), or electric, or manual, etc.

[0051] The variable volume chamber 15 may be obtained, at least partially, inside the second half mould 11.

[0052] The flow channels 16 may be obtained, at least partially, inside the second half mould 11.

[0053] The piston means 14 may be, as in this case, slidably coupled with the guide means 12. It is possible to provide, for example, a slidable coupling of telescopic type. The piston means 14 may be, in particular, arranged at least partially between the second half mould 11 and the (flange) body 13. The (screw) thrusting means 17 may be, as in the specific embodiment disclosed here, screw coupled with the (flange) body 13.

[0054] The joint system 1 may comprise, in particular, elastic means 19 (for example made of metal material and/or of elastomeric material) interposed operationally between the piston means 14 and the mould means (the second half mould 11) to promote a return movement of the piston means 14 (movement that increases the volume of the variable volume chamber 15).

[0055] The injection means may comprise, as in this specific embodiment, heating means 20 inserted at least partially inside the mould means, so that the dose of material received into the chamber in solid format may be transformed by heating into a dose in injectable pasty format.

[0056] The heating means 20 may comprise, in particular, at least one electrical resistance inserted into the first half mould 10.

[0057] The heating means 20 may comprise, in particular, at least one electrical resistance inserted into the second half mould 11.

[0058] The joint system 1 may comprise sensor means for detecting the temperature of at least one portion of the system, for example the temperature of the first half mould 10 and/or of the second half mould 11.

[0059] The heating means and/or the temperature sensor means may be configured in such a manner as to form an interchangeable section. [0060] The joint system 1 may be provided, in particular, with (electronic programmable) control means to control the temperature and/or the work cycle. This control means may comprise, in particular, a remote unit connected in a wireless manner to the heating means 20.

[0061] The joint system 1 may be, for example, a system that is transportable by hand by an operator. For this purpose, the system 1 may be provided, as in this case, with handle means 21 that is graspable by at least one operator to transport the system 1. In the specific case, the handle means 21 comprises two spaced handles.

[0062] The joint system 1 may be provided, in particular, with anchoring means removably anchored to an external structure, for example to a (metal) part of the wind power plant (for example a tower or a portion of an accessibility window for performing maintenance or repair tasks) having the turbine mounted on the shaft to which the sealing ring R is applied.

[0063] Such removable anchoring means may be designed in function of the multiplicity of different types of wind power plants, in particular to adapt to the various solutions envisaged by the manufacturers of towers for wind power plants. Such removable anchoring means may comprise, for example, a plate that is adaptable to the external structure, which may be fixed (screwed) in a manner that is integral with the mould means (for example integral with the first half mould 10) and thus in turn fixed (by magnetic fixing means, screws, etc) to a stiff element of the wind power plant, at the moment of moulding the joint.

[0064] In the specific case disclosed here, one embodiment of sealing ring R has been illustrated that is provided with a certain section. Nevertheless, the joint system 1 may be used universally to join any sealing element or system, with any elastomeric profile in the most varied applications and/or sections, by simply replacing the interchangeable elements of the assemblable system.

[0065] In use, the dose of material for seals (elastomeric material) will be positioned in the variable volume chamber 15, for example in a solid format, then the dose of material may be heated by the heating means 20 until an injectable pasty state is reached, then the dose of material will be subjected to pressure by piston means 14 driven by the thrusting means 17, driven by a machine tool (portable drill) outside the system, or driven by other driving means, for example driving means of the hydraulic, pneumatic, electric, manual, etc pump type. The dose of injected material will enter the moulding cavity 9 to make the joint portion.

[0066] With reference to figures 6 and 7, one embodiment is shown in which the thrusting means 17 is driven by fluid driving means that comprises, in particular, at least one (single action) linear actuator that may comprise at least one movable element 22 (piston) that is (integrally) connected to the thrusting means 17 and is slidable within a chamber 23. The thrusting means 17 may be slidable inside a tubular element 24 (ring nut) fixed (for example by a screw connection) to the body 13. The chamber 23 may be defined at least partially by a (cylindrical) portion of the body 13 and/or by the tubular element 24. The fluid driving means comprises at least one inlet 25 for the operating fluid (for example pressurised air) that is suitable for moving the movable element 22. The inlet 25 may be connected to a source of pressurised fluid (which is not shown).

[0067] With reference to figures 8 to 12, an embodiment is shown in which the material for seals is compression-moulded (rather than injection-moulded as in the preceding embodiments). The thrusting means 17 may be driven by fluid driving means. The dose of material for seals (for example elastomeric material and/or rubberised fabric) is positioned directly in the moulding cavity 9 (with the half moulds 10 and 11 in an open configuration) and is then compression-moulded between the two half moulds 10 and 11. The second half mould 11 is pushed into a closing position by the thrusting means 17 that may operate with one end in forced contact with the second half mould 11. Between the first half mould 10 and the second half mould 11 it is possible to define a runs collecting space 26 that is contiguous with the moulding cavity 9.

[0068] The joint systems disclosed above are usable for joining suitable materials for producing seals: these materials may comprise, for example, nitrile butadiene rubber, fluoroelastomers, rubberised fabrics, etc.

[0069] Each of the hot joint systems in situ disclosed above may be connected to an (electronic programmable) control system. The control system may comprise, for example, an electric power panel (figure 13) provided with a control panel and with suitable instrumentation for the electric supply of the joint system. The electric power panel may have, in particular, also the function of disconnecting electrically at least one joint system connected thereto or at least one part thereof, for example, in the event of a fault or maintenance. The electric power panel may be connected to the joint system by (removable) electric connecting means, for example by one or more electric cables and one or more temperature transducers (thermocouples) for adjusting the temperature. The electric connecting means may comprise, in particular, one or more socket-plug pairs in such as manner as to provide an easily transportable and dismantleable apparatus.

[0070] In use, the joint system (hot mould in situ) may be connected to the electric power panel by coupling the electric cables with the control panel and switching on the latter by a master switch. The operator is thus able to set the data for running the joint system. The settable parameters may comprise, in particular, the vulcanisation temperature and/or the vulcanisation time and/or the operating pressure.

[0071] The work parameters of the joint system may be preset (for example during the joint system assembly step) in the control system, for example in an electronic memory of the system, so the operator does not necessarily have to set the parameters, which may already be contained inside the control system (enclosed in a box of the control panel). Outside, the control panel may have (visible to the operator) a (light) signal to warn that the control panel is switched on and/or a (light) signal to indicate when a transducer (thermocouple) has reached the desired temperature and/or a (light) signal to warn that the desired vulcanisation time has been reached. The vulcanisation time may start, for example, from the moment in which the closing device is driven (electric and/or manual pump) that closes the joint system and takes the joint system to the desired operating pressure.

[0072] In figure 13 a diagram of a usable electric power panel is shown. With 27 a handle for transporting the electric power panel, with 28 a master switch, with 29 two heating switches for two mould portions, with 30 a driving switch that starts vulcanisation time, with 31 an ON-OFF switch, with 32 a voltage light, with 33 an alarm light, with 34 a heating switch, with 35 a vulcanisation stop indicator (buzzer), with 36 and 37 two user interfaces (for example of graphic type, in particular each with a screen and one or more switches for the entry of the data) for setting the parameters of the two mould portions, with 38 a dial of the vulcanisation time, with 39 and 40 the electrical couplings of the temperature probes, with 41 and 42 the electrical couplings for supplying the two mould portions have been indicated.