MXPA96006631A - A diaphragm seal for a high volt switching environment - Google Patents

Abstract

The present invention relates to a diaphragm for the contact insulator box of a mechanically operated high voltage switch. The diaphragm has a central part through which it passes to the shaft from the mechanical operator mechanism to the movable contact. The walls of the diaphragm around the central part are mechanically joined or units chemically to the shaft. The diaphragm is made of such materials, is dimensioned and configured so that the diaphragm moves with the shaft and prevents a relative movement between them. The outer eyebrow of the diaphragm is mechanically or chemically linked to the commutator box. The quality of the diaphragm and seals allows them to withstand the application of the complete operating voltage of the switch

Description

DN BELLO DB DIAPHRAGM FOR DH ENVIRONMENT DB DB COMMUTATOR HIGH VOLTAGE CROSS REFERENCE TO THE RELATED APPLICATION U.S. Patent Application Series No. filed / 95 entitled "High Voltage Switches" by Glenn J. Luzzi and Lloyd B. Smith and assigned to the assignee of the present invention.

BACKGROUND OF THE INVENTION field of invention This invention is directed to the field of electrical switches and more particularly to an electrical switch whose contacts are located within an isolated environmental enclosure operated by a mechanical system outside the enclosure connected by an axis extending through a closing seal.

Description of Previous Art In existing systems, the use of a reciprocating or rotating shaft that extends through a seal into an insulating environment such as oil, SF or vacuum, it can, due to wear of the seal on one side of such an axis, allow the insulating medium to squeeze out of the enclosure or allow air to enter the enclosure and destroy the vacuum and thereby destroy the commutator insulation. As to not interfere with the movement of the operating axis, the seals have to be relatively thin and flexible and may not be located where it is possible to have the full system voltage applied to them. This makes the general switch and the operating device complex and very large. To prevent the loss of the insulating environment through a faulted seal, the complete switch including the contacts and other operating mechanisms can be placed in a large sealed chamber. However, this severely limits the possible locations for such a switch and often results in a location far from the system to be protected.

SYNTHESIS OF THE INVENTION The present invention overcomes the difficulties noted above with respect to prior art devices, by providing electrical contacts within an environmental insulating enclosure, a mechanical operation system external to the enclosure and connected to an operating axis through a diaphragm or seal which allows the movement of the shaft without damaging the seal itself, and which can withstand the application of the system voltage to it. The seal is chemically or mechanically attached to the shaft in such a way that there is no relative movement between the seal and the shaft and the seal flexes in direct response to the movement of the shaft. At one end, the shaft is connected to a moving contact within the enclosure. The other end of the shaft is connected to a mechanical operating mechanism. The seal or diaphragm may be molded as a part of the insulating environmental enclosure or these may be molded or otherwise formed separately and joined to the enclosure by mechanical or chemical means such as the retaining or joining rings. It is an object of the present invention to provide a novel seal for an insulating environmental enclosure having a movable assembly therein.

It is an object of the present invention to provide a novel diaphragm or seal which allows the contact of a high voltage electrical switch to be located in an insulating environmental enclosure while the mechanical operator mechanism is outside such enclosure.

It is another object of the present invention to provide a mechanically operated electrical switch which allows the contacts of an electrical switch of medium to high voltage to be located in an insulating environmental enclosure while the mechanical operating mechanism is outside such enclosure and connected to said contacts through an operator shaft that extends through an enclosure seal.

It is still another object of the present invention. provide a seal for an insulating environmental enclosure which is attached to an operator shaft that moves reciprocally without a relative movement between such seal and shaft.

It is still another object of the present invention to provide a seal for an insulating environmental enclosure which is attached to an operator shaft that reciprocates and which flexes with the movement of such axis.

It is another object of the present invention to provide a mechanically operating electrical switch which allows the contacts of an electrical switch of medium to high voltage to be located in an insulating environmental enclosure while the mechanical operating mechanism is outside such enclosure and connected to said contacts by means of an operation axis that extends through an enclosure seal.

It is yet another object of the present invention to provide a novel seal for isolating an ambient enclosure which is attached to an operator shaft that reciprocates without a relative movement between such seal and shaft.

It is yet another object of the present invention to provide a novel seal to an insulating environmental enclosure on the which is attached to an operator axis that moves reciprocally and which flexes with the movement to that axis.

It is another object of the present invention to provide a novel seal for an insulating environmental enclosure which is attached to an operator shaft that reciprocates by chemical means and which flexes with the movement of such axis.

It is yet another object of the present invention to provide a novel seal for an insulating environmental enclosure which is attached to an operator shaft that reciprocates through mechanical means and which flexes with the movement of such an axis.

Other objects and features of the invention will be pointed out in the following description and claims and are illustrated in the accompanying drawings, which describe, by way of example, the principles of the invention and the best modes which are currently contemplated for carrying them out. .

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings in which similar elements are given similar reference characters: Figure 1 is a fragmentary, side elevational view, partially in section of a high voltage switch showing the position of a seal or diaphragm embodiment, constructed in accordance with the concepts of the invention, with respect to such a switch; Figure 2 is a fragmentary side elevational view, partly in section of a high voltage switch showing the position of a second embodiment of a seal or diaphragm, constructed in accordance with the concepts of the invention, with respect to such a switch; Figures 3 to 8 are side elevational views, partially in section of alternate embodiments of seals or diaphragms constructed in accordance with the concepts of the invention.

DESCRIPTION OF THE PREFERRED MODALITIES Turning now to Figure 1, a high-voltage switch is shown, of the type generally used in the voltage range of 3 KV to 38 KV. The commutator has a box part 10 formed of a dielectric elastomer such as an ethylene propylene diene monomer elastomer (EPDM), natural or synthetic rubber or the like. Around the box part 10 is an outer support shell or cover 42 formed of a rigid electrical conductive material such as stainless steel. Formed with a gap-free interface, a semiconductor layer 32 lines the hole 12 of the box part 10. The layer 32 is made of the same EPDM material as the box part 10 with the addition of a conductor of material such as black of smoke. Within the conductive insert 32 is formed a stiff tubular reinforcing element 36 which extends virtually to the full length of the box part 10. This element 36 is made of a dielectric material having a high physical strength.

A contact assembly 60, between an operator end support 46 and a fixed end 16 has a fixed contact 68 and a mobile contact 70 and a bottle 62 around it. The bottle 62, ceramic or other similar materials, has a fixed metal end cover 64 and an operator end cover 66 which includes the flexible and extendable metal bellows. The mobile contact 76 is connected by a rod-like operating element 72 placed on the outside of the bellows and which constitutes an extension of the movable contact 70. The contacts 68 and 70 are surrounded by a metal shield 76 and the bottle 62 is hermetically sealed The interior of the bottle is a controlled atmosphere and may contain an arc suppressing gas such as SFt.

The exterior of the bottle 62 is insulated by a filler dielectric 80 which occupies the space between the outside of the bottle 62 and the interior of the reinforcing element 36.

The operator element 72 is connected to a slidable hinge 98 which in turn is connected to a yoke 102. A bolt 106 and a coil compression spring 104 ensure that the movement of the yoke 102 is applied to the slidable hinge 98 and by both to the movable contact 70. The yoke 102 in turn is connected to an actuator shaft 108 by an elastic bump ring 114 which is engaged in the groove 112 on the shaft 108 and the groove 110 in the end wall of the yoke 102 The shaft 108 is connected to a drive assembly 120, as shown and described in the copending application cited above. Positioned on the end of the outer support member 42 is an annular ring 128 dimensioned such that it fits within the support member 42 and is secured to the support member 42 by the fasteners 131 which may be machined screws, metal screws autotape, borders or similar.

To seal the end 18 of a box part 10 while allowing the actuating element or shaft 108 to enter the box part 10, a seal or diaphragm 26 is employed. The seal or diaphragm 26 is molded from the same type of elastomer EPDM that the box part 10 and can be molded at the same time and as a part of the box part 10 as shown in the Figures 1, 2 and 3 or can be molded as a separate part and attached or otherwise attached to the box part 10. The seal or diaphragm 26 has an opening 31 in its center 30 and can include a hub which extends to along the surface of the element 108 outwards from the main seal body or diaphragm 26. The walls define the opening 31 can be chemically or mechanically joined to the element 108 and do not allow relative movement therebetween. Therefore, the destructive forces of the environment and the movement of the element 108 do not cause an increase in the opening 31 by the constant linear or rotational movement that can wear out the seal of the diaphragm and cause it to fail as is true in prior art devices.

The diaphragm body 26 between its center 30 and its outer eyebrow can be corrugated as shown in Figures 1, 4, 6, 7 and 8, it can be linear as in Figure 2, or a combination of linear and curved parts as it is shown in figure 3.

Turning now to Figure 1, the diaphragm 26 is molded as a part of the box part 10 and is therefore made of an insulating EPDM elastomer. An outer edge 300 is in contact with the inner surface of the outer support member 42, is attached to the element 42 using a chemical binding agent such as a binding agent sold under the Chemlok 205 brand and, if desired, with well-known conventional adhesion promoting agents. The opening 31 is intentionally made smaller than the outer diameter of the actuating element 108 so that the material around the opening 31 is stretched and will firmly grip the outer perimeter of the element 108. The joint between the outer perimeter element 108 and the walls around the opening 31 are also chemically bonded. The seal or diaphragm 26, the body 302 is formed as a series of corrugations 28 that extend from the central opening 31 towards the outer edge 300. The corrugations 28 can expand or contract as the element 108 moves so as not to impede the movement of the body. item 108.

The seals between the upper edge 300 of the diaphragm 26 and the support member 42 and between the diaphragm 26 and around the opening 31 and the actuating element 108 as well as the diaphragm 26, itself, must have full voltage support capabilities. This means that the seal or diaphragm 26 must be made of a material, must have a thickness and uniformity of material, and the seals of the diaphragm with the support element 42 and the element 108 must be able to withstand the maximum voltage that is going to be printed between the current-carrying elements of the inter-switch and earth during service or during fault conditions. For example, on a switch intended to be operated from one phase to the next Nominal 25 KV, the diaphragm and seals must be able to withstand about 14.4 KV continuously.

In Figure 2, the diaphragm 316 is molded as a part of the box part 310. The central part 31 has the hubs 314 and 318 formed around it to provide an increased surface contact with the actuating member 108. The central opening 320 extends through the central part 312 as well as the hub 314 and the hub 318 to a ring lad 128. An eyebrow 322 extends beyond the body 324 and makes contact with the ring 128 to provide more aislant to one side of the support 42. The body 324 is a line between the central part 312 and the outer surface in contact with the outer support element 42 and is inclined outwards from the central part 312 towards the element 42. As the actuating element 108 moves to the Right in Figure 2, to move the mobile contact 70 to make contact with the fixed contact 68, as shown in Figure 1, the body 324 is compressed. This expands to its previous configuration when the movable contact 70 returns to the open position.

Figure 3 shows a diaphragm 326 having a central part 328 and a hub 330 extending toward the position of the yoke 102 (not shown). The diaphragm 326 has a single hub 330 also extending inwardly and an eyebrow 336 to engage the inwardly facing arms 129 of the ring 128.

The opening 338 extends through the central portion 328 and the hub 330. The body 339 is made of two linear parts 340, 344, with a curved portion 342 therebetween. The diaphragms 316 and 326 are chemically linked to the axis or actuating element 108.

The seal or diaphragm 346 of Figure 4 is similar to that of Figure 1, except that the latter is molded separately and then attached to the box part and the outer support member 42. The edges of the arms face inwardly. 129 are tapered as at point 348 to provide a space 350 for accommodating the diaphragm 346 as the element 108 moves to the left in FIG. 4. The diaphragm 346 is also chemically attached to the element 108.

Figure 5 shows a diaphragm 356 similar to the diaphragm 346 of Figure 4, except that the diaphragm 356 has a hub 358 extending in the forward direction toward the yoke 102. The hub 358 has a crimpable ring 360 positioned around it and the ring 360 is curled using a suitable tool and dies as is known in the art. Upon completion of the curling operation, the ring 360 will have planes 362 on its outer surface. The ring 360 can also be compressed on the hub 358 and the element 108 by forging, meshing or other similar operations to decrease the inner diameter of the ring 360.

To mechanically cause the engagement of the diaphragm 366 of Figure 6 with the actuator element 108 ', the actuator element 108' can be modified to have a protruding annular shoulder 368 which rests on the front surface of the diaphragm 366 on one side of the part. central 370. A nut 372 can be applied against the opposite face of the diaphragm 366. The tightening effect of the nut 372 on the threaded portion of the element 108 '(not shown) is to force the diaphragm 366 against the shoulder 368. and compressing the diaphragm and causing the walls to define the opening 371 to grip the outer surface of the element 108 'tightly. The nut 372 can be replaced with a crimping ring or the like. The seal 366 is also independently molded and is attached to the box part 10 and the support member 42.

Figure 7 shows a diaphragm 376 which is mechanically attached to an actuating element 378 and is only attached to the box part 10 (not shown). The actuating element 378 has an annular shoulder 380 adjacent the end 382. The annular shoulder 380 lies against the flat surface 386 of a collar 384 whose curved surface 388 is formed in the central portion 390 of the diaphragm 376. A second washer 392 having a surface conforming to the rear surface of the central part 390 is forced against the diaphragm 376 by the nut 394. The opening through the central part 390 is therefore made to decrease in diameter.

Figure 8 shows a diaphragm 396 which is chemically attached to the element 108 and only to the box part 10 (not shown). The diaphragm 396 is similar to the diaphragm 26 of FIG. 1, but has the corrugations 398 that are longer along the length of the element 108 than the corrugations 28 of the diaphragm 26. This reduces the amount of movement of the corrugations 398 in comparison to corrugations 28 when element 108 is moved.

As clearly seen from the seals or diaphragms shown, the seals or diaphragms can be molded as part of the general isolation of the electrical switch, they can be molded separately and attached to the insulating layer and the inside of the outer conductive support layer, they can be chemically bonded or mechanically attached to the actuating shaft passing through a hole in the central part and can have a body part made of linear segments, curved segments and a combination of linear and curved segments. The material from which the seal or diaphragm is made and its thickness as well as the joints between the diaphragm and the shaft and the diaphragm and the switch box must be such that it supports the full operating voltage of the electrical system.

Although the fundamental novel features of the invention have been shown and described and pointed out, coo is applied to the preferred embodiments, it will be understood that several Submissions and substitutions and changes in the forms and details of the illustrated devices and their operation can be made by those skilled in the art, without departing from the spirit of the invention.

Claims (46)

R B I V I M D I C A C I OM B B

1. A mechanically operated switch comprising: a) a switch body having a first end and a second end and a central hole therethrough; b) a first contact member adjacent said first body end for connecting a first electric wire thereto; c) a second contact member between said first and second ends of the body for connecting a second electrical cable thereto; d) a first fixed electrical contact in said central hole on one side of the first body end and coupled to said first contact member; e) a second moving electrical contact in said intermediate central hole between said first and second ends and coupled to said second contact member, said second moving electrical contact is able to move between a first position making contact with the first contact fixed electrical and a second position separated from said first fixed electrical contact; f) an operating axis, having a first end and a second end, said first end of the shaft extending through said second body end, a portion of said central hole and coupled to said second mobile electrical contact for moving said second contact mobile between the first and second positions; g) sealing means coupled to said operating axis and at its outer periphery to the wall of said body defining said central hole to seal said second end of said body; Y h) mechanical means coupled to said second end of said operation axis for selectively placing said second mobile electrical contact with respect to said first fixed electrical contact.

2. A mechanically operated electrical commutator as claimed in clause 1, characterized in that said sealing means have a central opening through which said operator shaft passes.

3. A mechanically operated electrical commutator as claimed in clause 2, characterized in that said operating means are chemically coupled to said operating axis placed in said central opening.

4. A mechanically operated electrical commutator as claimed in clause 3, characterized in that said chemical coupling employs a bonding agent.

5. A mechanically operated electrical commutator as claimed in clause 2, characterized in that said sealing means are mechanically coupled to said operator shaft placed in said central opening.

6. A mechanically operated electrical commutator as claimed in clause 5, characterized in that said mechanical coupler employs a compressed ring around said sealing means and said shaft.

7. A mechanically operated electrical switch as claimed in clause 5, characterized in that said mechanical coupler employs an annular ring on said operating axis to engage a first surface of said sealing means and a series mechanism on said operating axis for engaging the second surface of said sealing means and said sealing means are compressed by said annular ring and said closing means when said closing means are applied to said operator axis.

8. A mechanically operated electrical commutator as claimed in clause 1, characterized in that said sealing means are flexible and elastic.

9. A mechanically operated electrical commutator as claimed in clause 8, characterized in that said sealing means have a central opening in which the operator shaft is placed.

10. A mechanically operated electrical commutator as claimed in clause 9, characterized in that said sealing means are mechanically coupled to said operating shaft placed in said central opening.

11. A mechanically operated electrical commutator as claimed in clause 10, characterized in that said chemical coupler employs a joining agent.

12. A mechanically operated electrical commutator as claimed in clause 9, characterized in that said sealing means are mechanically coupled to said operating shaft placed in said central opening.

13. A mechanically operated electrical commutator as claimed in clause 12, characterized in that said mechanical coupler employs a compressed ring around said sealing means and said shaft.

14. A mechanically operated electrical switch as claimed in clause 12, characterized in that said mechanical coupler employs an annular ring on said operator shaft to engage a first surface of said sealing means and a closing mechanism on said operator shaft to engage the second surface of said sealing means and said sealing means are compressed by said annular ring and said closing means when said closing means are applied to the operating shaft.

15. A mechanically operated electrical switch as claimed in clause 1, characterized in that said sealing means are made of a dielectric material to prevent arcing from said first fixed contact and said second contact mobile to said mechanical means.

16. A mechanically operated electrical commutator as claimed in clause 15, characterized in that said sealing means have a central opening in which said operator shaft is placed.

17. A mechanically operated electrical commutator as claimed in clause 16, characterized in that said sealing means are chemically coupled to said operating shaft placed in said central opening.

18. A mechanically operated electrical commutator as claimed in clause 17, characterized in that said chemical coupling employs a binding agent.

19. A mechanically operated electrical commutator as claimed in clause 16, characterized in that said sealing means are mechanically coupled to said operating shaft placed in said central opening.

20. A mechanically operated electrical commutator as claimed in clause 19, characterized in that said mechanical coupler employs a compressed ring around said sealing means and said shaft.

21. A mechanically operated electrical switch as claimed in clause 19, characterized in that said mechanical coupler employs an annular ring on said operating axis to engage a first surface of said sealing means and a closing mechanism on said operator shaft to engage the second surface of said sealing means and said sealing means are compressed by said annular ring and said fixing means to be applied said closing means to said operator axis.

22. A mechanically operated electrical commutator as claimed in clause 1, characterized in that said sealing means are formed integrally with said commutator body.

23. A mechanically operated electrical commutator as claimed in clause 1, characterized in that said outer periphery of said sealing means are chemically bonded to the wall of said body defining said central orifice.

24. A mechanically operated electrical commutator as claimed in clause 1, characterized in that said outer periphery of said sealing means are adjusted by pressure inside the orifice of said body.

25. A mechanically operated electrical commutator as claimed in clause 3, characterized in that said outer periphery of said sealing means are chemically bonded to the wall of said body defining said central hole.

26. A mechanically operated electrical commutator as claimed in clause 3, characterized in that said outer periphery of said sealing means is press fit within said orifice of said body.

27. A mechanically operated electrical commutator as claimed in clause 7, characterized in that said sealing means are formed integrally with said commutator body.

28. A mechanically operated electrical commutator as claimed in clause 5, characterized in that said outer periphery of said sealing means are chemically joined to the wall of said body defining said central orifice.

29. A mechanically operated electrical commutator as claimed in clause 5, characterized in that said outer periphery of said sealing means is press fit within said central orifice of said body.

30. A mechanically operated electrical commutator as claimed in clause 10, characterized in that said sealing means are formed integrally with said commutator body.

31. A mechanically operated electrical commutator as claimed in clause 10, characterized in that said outer periphery of said sealing means are chemically joined to the wall of said body defining said central orifice.

32. A mechanically operated electrical commutator as claimed in clause 10, characterized in that said outer periphery of said sealing means are press fit within the central orifice of said body.

33. A mechanically operated electrical commutator as claimed in clause 12, characterized in that said sealing means are formed integrally with said commutator body.

34. A mechanically operated electrical commutator as claimed in clause 12, characterized in that said outer periphery of said sealing means are chemically bonded to the wall of said body defined by said central hole.

35. A mechanically operated electrical commutator as claimed in clause 12, characterized in that said outer periphery of said sealing means are adjusted with pressure inside the central hole of said body.

36. A mechanically operated electrical commutator as claimed in clause 17, characterized in that said sealing means are formed integrally with said commutator body.

37. A mechanically operated electrical commutator as claimed in clause 17, characterized in that said periphery of said sealing means is chemically linked to the wall of said body defining said central hole.

38. A mechanically operated electrical commutator as claimed in clause 17, characterized in that said outer periphery of said sealing means press fit into said central hole of said body.

39. A mechanically operated electrical commutator as claimed in clause 19, characterized in that said sealing means are formed integrally with said commutator body.

40. A mechanically operated electrical commutator as claimed in clause 19, characterized in that said outer periphery of said sealing means are chemically joined to the wall of said body defining a central hole.

41. A mechanically operated electrical commutator as claimed in clause 19, characterized in that said outer periphery of said sealing means is press fit within the central orifice of said body.

42. A mechanically operated electrical commutator as claimed in clause 32, characterized in that the sealing means further comprises: a) a first surface and a second surface; Y b) a cube around said central opening extending from at least one of the first and second surfaces.

43. A mechanically operated electrical commutator as claimed in clause 2, characterized in that said sealing means further comprises: a) a first surface and a second surface; Y b) a hub around said central opening extending from both the first and second surfaces.

44. A mechanically operated electrical commutator as claimed in clause 42, characterized in that said first surface and said second surface of said central opening at said periphery are parallel and linear.

45. A mechanically operated electrical commutator as claimed in clause 42, characterized in that said first surface and said second surface of said central opening to said outer periphery are parallel and made of segments which are curved and linear.

46. A mechanically operated electrical switch as claimed in clause 45, characterized in that said first and second surfaces comprise: a) a first linear segment perpendicular to said operation axis extending outside said central opening; b) a second linear segment perpendicular to said operating axis extending inward from said outer periphery towards the central opening, said second segment moving along said operating axis with respect to said first axis; Y c) a curved segment joining said first and second linear segments. SUMMARY A diaphragm for the contact isolation box of a mechanically operated high-voltage switch. The diaphragm has a central part through which the shaft passes from the mechanical operator mechanism to the moving contact. The walls of the diaphragm around the central part are mechanically joined or chemically attached to the shaft. The diaphragm is made of such materials, is dimensioned and configured so that the diaphragm moves with the shaft and prevents a relative movement between them. The outer eyebrow of the diaphragm is mechanically or chemically attached to the commutator box. The quality of the diaphragm and seals allows them to withstand the application of the complete operating voltage of the switch.