EP1139367B1 - Load-breaking module with vacuum bottle and fixing means, and switchgear using such a module - Google Patents

Description

The invention relates to a module for electrical switchgear, comprising a vacuum bulb and means for fixing the bulb to a support frame. It also relates to an apparatus comprising at least one such module.

Conventionally, a vacuum interrupter comprises a body forming a sealed enclosure and enclosing a pair of separable contacts, with at least one movable contact. The movable contact is secured to a metal rod movable in translation parallel to its axis and projecting at a first axial end of the bulb. A seal is made between the rod and a wall of the enclosure, by means of a bellows allowing the translational movement of the rod. This rod is intended to be connected to a drive mechanism of the bulb. The other contact is in general a fixed contact secured to a fixed rod which passes through the body of the bulb, so as to be accessible from the outside to a second axial end of the bulb, opposite to the first. The movable rod is guided in its axial movement relative to the bulb through a guide sleeve integral with the body of the bulb and projecting inwardly of the bulb. Various examples of realization of this architecture are illustrated in the documents DE 24 40 827 , US-A-4,403,124 , US 4,933,518 , US 4,983,793 , US 5,004,877 and US 5,168,139 .

In the document EP 0 058 519 is described a three-phase electrical switchgear, each phase comprises a vacuum bulb of the type described above, supported by a rigid frame of insulating material. On the side of the first axial end, the body of the bulb is fixed to the frame by means of a support plate provided with a bore with the diameter of the first axial end, and forming a seat for the body of the bulb. On the side of the second axial end, the body of the bulb is fixed to the frame by means of a fixed rod fixing nut to an electrical connection range secured to the frame. There is no interaction between the support plate and the rod.

At the free end of the rod is fixed by hooping a flexible electrical connection. When mounting the device, the bonding operation of the bonding necessarily takes place after the bulb has been mounted on the support plate, since the bonded connection is too large to pass through the bore of the plate support. Furthermore, the positioning of the bulb on its frame must be performed accurately, so as not to solicit the rod of the movable contact out of its axis of translation determined by the inner guide sleeve to the bulb. These points prove disadvantageous during the industrialization of the equipment.

An object of the invention is to facilitate the assembly of electrical switchgear vacuum interrupter, including the break module constituted by the bulb and its support frame.

• au moins une ampoule à vide comportant un corps formant une enceinte renfermant une paire de contacts séparables, un desdits contacts étant solidaire d'une tige métallique mobile, une partie de la tige faisant saillie hors de l'enceinte à une première extrémité axiale du corps de l'ampoule ;
• un bâti de support de l'ampoule ;
• caractérisé en ce qu'il comporte en outre un collier de fixation et de guidage comportant :
  • une lumière formant un fourreau axial de guidage de la tige de l'ampoule, assurant un guidage en translation de la tige par rapport au collier suivant un axe géométrique de la lumière ; et
  • des surfaces de positionnement radial coopérant avec le corps de l'ampoule et interdisant tout mouvement radial du corps de l'ampoule par rapport à l'axe géométrique de la lumière du collier ;
  • des moyens de fixation au bâti de support de l'ampoule.

For this purpose, the subject of the invention is a breaking module for electrical switchgear, comprising

• at least one vacuum interrupter comprising a body forming an enclosure enclosing a pair of separable contacts, one of said contacts being integral with a movable metal rod, a portion of the rod projecting from the enclosure at a first axial end of the body of the bulb;
• a support frame of the bulb;
• characterized in that it further comprises a fastening and guiding collar comprising:
  • a light forming an axial guide sleeve of the stem of the bulb, providing guidance in translation of the rod relative to the collar along a geometric axis of the light; and
  • radial positioning surfaces cooperating with the bulb body and preventing any radial movement of the bulb body relative to the geometric axis of the collar lumen;
  • fastening means to the support frame of the bulb.

The collar allows both the guiding of the rod relative to the bulb and the fixing of the bulb relative to the frame. The chain of dimensions is reduced, resulting in greater guiding accuracy, provided at low cost.

Advantageously, the frame is provided with guide rails and the collar is slidably shaped so as to slide in said guide rails, in a direction perpendicular to the geometric axis of the light. It is then possible to assemble the bulb and its collar, before inserting the assembly in the frame, by sliding the collar in the slides. According to one embodiment, the fastening means comprise elastic clips forming a fastening by clips. This fastening mode by staples makes mounting particularly simple. The staples are preferably located on the collar, and cooperate with supports located on the frame.

Preferably, the collar is composed of two parts able to take one relative to the other an open position allowing the radial insertion of the stem of the bulb and a closed position ensuring the cooperation of the radial positioning surfaces with the body of the bulb, and light with the stem. This particularly advantageous arrangement makes it possible to mount the flexible conductor on the stem of the bulb before mounting the collar to fix the bulb in its frame. According to a preferred embodiment, the two parts of the collar are hinged to each other by a hinge. The two parts of the collar in the closed position are fixed to one another by fixing means. These arrangements facilitate assembly.

Preferably, the collar is provided with axial positioning surface constituting a seat for an axial end portion of the body of the bulb. The positioning of the collar is simplified.

According to one embodiment, the collar is made of plastic. It may be for example a polyamide 6-6.

Preferably, the module comprises a single vacuum bulb.

According to another aspect of the invention, it also relates to an electrical switchgear comprising at least one module as described above, and a drive mechanism of the rod of said module.

• la figure 1 représente une vue en perspective d'un appareillage selon l'invention, comportant une ampoule à vide installée dans un bâti support ;
• la figure 2 représente une vue en coupe axiale de l'appareillage de la figure 1 ;
• la figure 3 représente une liaison électrique souple permettant une liaison électrique entre l'ampoule et une plage de raccordement ;
• la figure 4 représente une vue éclatée d'une partie de l'appareillage avant son assemblage ;
• la figure 5 représente schématiquement une opération de brasage réalisant une jonction entre une tige de l'ampoule et la liaison électrique flexible.

Other advantages and features will emerge more clearly from the following description of a particular embodiment of the invention, given by way of non-limiting example, and represented in the accompanying drawings in which:

• the figure 1 represents a perspective view of an apparatus according to the invention, comprising a vacuum interrupter installed in a support frame;
• the figure 2 represents an axial sectional view of the apparatus of the figure 1 ;
• the figure 3 represents a flexible electrical connection allowing an electrical connection between the bulb and a connection pad;
• the figure 4 represents an exploded view of part of the apparatus before assembly;
• the figure 5 schematically represents a brazing operation forming a junction between a rod of the bulb and the flexible electrical connection.

With reference to figures 1 and 2 , a switchgear device comprises a vacuum bulb 10 supported by a frame 12 and driven by a mechanism 13 of conventional type. Two connection areas 14 and 16, fixed to the frame 12, are intended to electrically connect the equipment to a busbar (not shown).

Here, the generic expression of a vacuum bulb designates a set of known type, comprising a cylindrical body 17 forming an enclosure 18 where there is a relative vacuum and which encloses a pair of separable contacts 22, 24. The body 17 is itself - Even divided into a medial insulator section 19 of insulating material, a first metal end section constituting a first closure flange, and a second metal end section 21 constituting a second closure flange. One of the contacts is a pellet 22 soldered at the end of a conducting cylinder 26 and constitutes with this cylinder a fixed contact member 28. The cylinder 26 passes through the second flange 21 and is welded thereto. The cylinder 26 is also welded to a rigid metal coil 29, it is welded to the connection pad 14. This ensures an electrical connection between the fixed contact member 28 and the connection pad 14, via the coil 29. The coil 29 is intended to induce, in the zone of separation of the contacts 22, 24, a magnetic field conducive to the breaking of an incipient electric arc between the contacts during their separation. Screws secure the turn 29 to the frame 12, and therefore the rigid attachment between the cylinder 26, itself secured to the body 17 of the bulb, and the frame 12. Moreover, and as will be explained later in detail, the first flange 20 is positioned and held relative to the frame 12 by means of a clamp 100 retained in a groove 130 of the frame.

The contact 24 is a pad brazed at the end of a movable contact member 30 whose body is constituted by a metal conductive rod 32, in this case a copper rod, passing through an orifice of the first flange 20. This rod 32 extends outside the enclosure, as can be seen more clearly on the figure 5 , by a portion 36 of smaller diameter, thus defining an intermediate shoulder 38. The end of the rod is provided with an axial threaded hole 39. A sealing bellows 40 brazed on the rod 32 and on the inner wall of the first end portion, allows an axial translational movement of the movable member 30 relative to the fixed contact member 28, while preserving the vacuum in the chamber 18.

The rod 32 is connected to a lever 80 with two parallel arms 81, 82, via an insulating arm 42. The insulating arm 42 comprises a plastic body 43 overmolding on the one hand the head of a first threaded rod 44, and secondly the head of a second threaded rod 45 located in the axial extension of the first. The first threaded rod 44 is screwed into the threaded blind hole 39 located at the end of the rod 32 of the bulb. On the second threaded rod 45 is screwed a tubular adjusting nut 46. The nut supports at one end a support plate 47 for the end of a contact pressure spring 48. The other end of the spring 48 bears on a second plate 49, which rests on a bar 83. The bar 83 has a bore 84 forming a guide sleeve traversed by the tubular nut 46. The bar 83 freely journalled in lateral axes 85 supported by the arms 81, 82 of the lever 80. The guide sleeve 84 allows both the translation of the nut 46 parallel to its axis and its free rotation. Nut 46 features a shoulder that rests on the portion of the bar 83 opposite the second plate 49. The two arms 81, 82 of the lever 80 pivot about an axis 86 supported by the frame 12 and are actuated jointly at their free end by a mechanism closing and opening (not shown), this mechanism being intended to drive the movable contact member 30 between a contact position with the fixed contact member 28 and a separation position. At the opening, the lever 80 pivots counterclockwise about the axis 86 on the figure 2 , directly driving the bar 83, the nut 46, the arm 42 and the movable contact member 30. At closure, the lever 80 pivots clockwise about the axis 86, causing the rod 83 which compresses the spring 48 via the plate 49. The closing force is then transmitted by the spring 48 to the moving contact 30, via a transmission chain comprising the plate 47, the nut 46 and the insulating arm 42.

The electrical connection of the rod 32 to the busbar is provided by means of a flexible electrical connection 50, shown schematically on the figure 3 , one end 56 of which constitutes the connection pad 16, while the other end 58 is brazed to the body of the rod 32. The flexible link 50 is constituted by a stack of metal blades 52, in this case blades of copper. Each metal blade 52 has a curved medial portion 54 extended at each end by one of the end plane portions 56, 58. The blades 52 have different lengths and shapes, so as to together form a stack having the desired curved shape at the end. the level of the middle portion 54. At the ends 56, 58, the blades 52 are welded to each other by an atomic diffusion welding process, without adding material, so that each end forms a rigid one-piece portion. In their middle portion 54, the blades 52 remain separated from each other, which gives good overall flexibility to the electrical connection 50 thus formed. As illustrated by figure 4 , the end portion 56 constituting the connection area comprises fixing means 60, in this case threaded holes opening, allowing its attachment to the frame of the apparatus, and connection means 62, in this case other tapped holes, allowing its connection to a busbar. The other end portion 58 has a bore 64 corresponding to the diameter of the axis of the rod 36.

The collar 100, visible in detail on the figure 4 , is made of plastic, in this case a polyamide 6-6, and comprises two parts 101, 102 hinged together by a hinge 103, so as to take an open position of mounting shown on the figure 4 , as well as a closed position represented on the figure 2 , in which elastic hooks 104 are stuck in corresponding slots 106. The closed collar forms a flange having a flat bottom 107 and a peripheral cylindrical wall 108, for fitting therein the end of the first flange 20 of the bulb 10. The central part of the flat bottom has a light 120 allowing the passage of the rod 32 of the bulb. This light, of generally cylindrical shape, guides the rod 32. The collar 100 is provided with two main lateral rails 109, connected to the flat bottom 107 by two lateral lugs 110, and two auxiliary lateral rails 112 connected to the flat bottom 107. by two other lateral lugs 114. Each auxiliary rail 112 is in the extension of one of the main rails 109. Each main rail 109 forms in a front portion a stop 116 in recess, and in a rear portion an elastic clip 118.

The insulating portion 19 of the body 17 of the bulb is covered with an insulating sleeve 90 ( figure 2 ) equipped with vanes to lengthen the creepage distance between the live metal parts of the equipment. The sleeve 90 widens in its upper part and forms a lip 92 which covers a portion of the turn 29, so as to lengthen the distance between the metal parts under tension. An intermediate bead 94, whose internal surface is covered with a semiconductor paint, smooths the field lines in the vicinity of the edges of the turn 29.

The plastic body 43 of the insulating arm 42 forms a cylindrical skirt which protects the spring 48 and the threaded rod 45 and which thus ensures the electrical insulation between the rod 32 and the flexible connection 50 on the one hand, and the d 'somewhere else.

The mounting of the bulb 10 in the frame 12 is as follows. In a first step, the cylinder 26 is welded to the subassembly constituted by the turn 29 and the 14. The insulating sleeve 90 is then force-fitted on the body 17 of the bulb and on the coil 29.

The bulb 10 must then be equipped with its electrical connection 50. The axis 36 of the rod 32 is inserted into the bore 64, with the interposition of a washer of the metallic filler compound 68, according to the exploded diagram of FIG. figure 3 . The filler metal compound should have a relatively low melting temperature, preferably less than 700 ° C, so as not to damage the internal solders of the ampoule. In this case, it is in this example a compound of 56% silver, 22% copper, 17% zinc and 5% tin, whose melting point is of the order of 650 ° C. A heat source 70, shown schematically on the figure 5 at the free end of the bore, until the washer 68 is merged and axial capillary infiltration of a part of the metallic feed compound into the cylindrical space at the interface between the bore and the axis. In a manner well known to the brazing specialist, the initial clearance between the parts, namely between the bore and the axis, must be appropriately chosen firstly to promote, during brazing, the wetting of the surfaces to be assembled. and on the other hand to ensure the mechanical strength of the brazed joint in the subsequent conditions of use. The brazed joint 72 obtained reveals on the one hand a cylindrical interface zone 74 between the axis and the bore, and on the other hand an annular interface zone 76 between the upper rim of the bore 64 and the shoulder 38 of the rod.

This assembly being performed, the rod 32 is inserted radially into the collar 100 open, then the collar 100 is closed so as to encircle the end of the first flange 20 of the body 17 of the bulb and the rod 32, the elastic hooks 104 being stitched in corresponding lights 106. The assembly thus formed is then introduced laterally into the frame 12, the rails 109 being introduced into the lateral grooves 130, and forming with the latter a sliding guide. The collar then forms a slide that slides in the grooves 130 until the stops 116 meet corresponding surfaces of the frame, the staples 118 then being closed on corresponding bearing surfaces 132 of the frame. It then remains to screw to the frame 12 the connection pads 14, 16 and the coil 29, to screw the insulating arm in the threaded hole of the rod and to adjust the contact pressure with the adjusting nut .

In all rigor, the movement printed at the rod 32 of the bulb 10 by the lever 80 in the absence of play between the moving parts would not be perfectly straight with respect to the frame 12. However, the angle between the lever 80 and the rod 32 is always very close to the right angle, and the stroke of the rod 32 of the bulb between its open position and its closed position does not exceed a few millimeters, which corresponds to an angle of rotation lever 80 not exceeding a few degrees, so that in the absence of play, the radial movement of the rod 32 would be of the order of one hundredth of its axial stroke. In the embodiment described, this clearance is absorbed by the existing gaps between the various elements of the driveline, in particular at the level of the journals 85 and the axle 86. However, if a larger stroke was desired, It would be possible to guide the bar 126 in an oblong of the lever 90, 92, 94.

The subset thus formed forms a module that can be assembled and tested in the factory, before storing it independently of the mechanism 13. The final assembly of the equipment can be deferred. The modules make it possible to constitute apparatus different from each other by the number of poles arranged side by side.

Naturally, various variations are possible.

The slide guide can be reversed so that rails formed on the frame cooperate with grooves formed at the periphery of the collar. The fastening mode with elastic staples can be replaced by any other suitable method of attachment. The hinge can be omitted, so that the collar consists of two parts completely separated from each other in the open position. Other modifications are possible. For example, the sleeve may be omitted if the applied voltage permits. The transmission lever can be arranged so that its pivot is between the free end moved by the mechanism and the bar.

As has been said, the apparatus may be monopolar or multipolar. In the latter case, the frame can be common to the different poles arranged side by side. However, it is advantageous to have monopolar modules each having an independent frame, which promotes a very high degree of modularity. The mechanism can be of any known type for driving the lever 80: electromagnet, pole shaft mechanism. The switchgear can be of any type, for example: switch, circuit breaker, with or without sectioning characteristics. The vacuum bulb may comprise two movable contact members.

Claims (10)

1. A breaking module for an electrical switchgear apparatus, comprising:

   - at least one vacuum cartridge (10) comprising a body (17) forming an enclosure (18) containing a pair of separable contacts (22, 24), one (24) of said contacts being securedly affixed to a movable metal rod (32), a part of the rod (32) protruding out from the enclosure at a first axial end of the body (17) of the cartridge (10);

   - a support frame (12) of the cartridge;

   characterized in that it further comprises a fixing and guiding collar (100) comprising:

   - an aperture (120) forming an axial guide sheath of the rod (32) of the cartridge, performing guiding of the rod (32) in translation with respect to the collar (100) according to a geometric axis of the aperture (120);

   - radial positioning surfaces (108) co-operating with the body (17) of the cartridge and preventing any radial movement of the body (17) of the cartridge with respect to the geometric axis of the aperture (120) of the collar (100);

   - means for fixing to the support frame of the cartridge.
2. The breaking module according to claim 1, characterized in that

   - the frame (12) is provided with guiding slides (130);

   - the collar (100) is in the form of a slide-rack so as to slide in said guiding slides (130) in a direction perpendicular to the geometric axis of the aperture (120).
3. The breaking module according to any one of the foregoing claims, characterized in that the means for fixing comprise elastic clips (118) forming a fixing means by clipping.
4. The breaking module according to any one of the foregoing claims, characterized in that the collar (100) is composed of two parts (101, 102) able to take an open position with respect to one another enabling radial insertion of the rod (32) of the cartridge and a closed position wherein the radial positioning surfaces (108) cooperate with the body (17) of the cartridge and the aperture (120) co-operates with the rod (32).
5. The breaking module according to claim 4, characterized in that the two parts (101, 102) of the collar are articulated on one another by a hinge (103).
6. The breaking module according to claim 4, characterized in that the two parts (101, 102) of the collar (100) are secured to one another in the closed position by fixing means (104, 106).
7. The breaking module according to any one of the foregoing claims, characterized in that the collar (100) is provided with axial positioning surfaces (107) forming a seat for a section of axial end (20) of the body (17) of the cartridge.
8. The breaking module according to any one of the foregoing claims, characterized in that the collar (100) is made of plastic material.
9. The breaking module according to any one of the foregoing claims, characterized in that it comprises a single vacuum cartridge (10).
10. An electrical switchgear apparatus comprising at least one module according to one of the foregoing claims, and a drive mechanism (13) of the rod of said module.

Images