EP1139368A1 - Electrical multiphase interrupting device with a driving mechanism and switching modules - Google Patents

Abstract

The multipolar switching modules have a number of switching modules with separable contacts. There is a shaft (32) activating transmission levers (70,72,74) of the different modules opening and closing the modules. The mechanical activation swings on handles (36,38) of the shaft, defining a third geometric axis (144) pivoting parallel to the first axis (140). The other lever part pivots on a lower pivot (66).

Description

The invention relates to a multi-pole electrical switchgear, and particular to a multipolar switchgear comprising vacuum interrupters.

The document EP 0 346 603 describes an electrical apparatus for three-pole breaking comprising three identical polar cut-off modules arranged side by side on a frame. Each module has a vacuum interrupter fitted with a control rod mobile in translation. A known type spring drive mechanism comprising a pole shaft, allows the drive of the control rods of the three bulbs to empty. Each control rod is connected to the pole shaft by means of a independent linkage, specific to the corresponding cut-off module. This linkage is composed of a transmission lever, arranged between two connecting rods, one of the connecting rods the lever to a crank of the pole shaft and the other connecting the lever to the rod vacuum bulb control. In practice, the vacuum bulbs of the different poles are likely to be subjected, during opening and closing, to stresses different. When opening, it may happen that the contacts of a bulb are slightly welded, or on the contrary that the electromagnetic forces induced by the currents on the contacts tend to more violently separate the contacts from one of the light bulbs. When closing, especially if it takes place on a short circuit for one of the poles, one of the contacts can be subjected to very significant repulsion forces. Of made of these different stresses on the rods of the vacuum bulbs of the different poles, the pole shaft is subjected to significant torsional stresses, directly transmitted by independent linkages from the different poles. There is then a risk of significant torsional dynamic deformation of the pole shaft, which results in non-simultaneous opening or closing of the various bulbs. To overcome this risk, it is then necessary to oversize the pole shaft, so that it provide additional torsional stiffness. Furthermore, the apparatus does not allow to easily vary the spacing between the vacuum bulbs of the different poles. It is true that the construction in identical and independent breaking modules would allow theoretically any arbitrary provision. However, at each distance between poles corresponds to a different pole tree, since the cranks of the pole tree must be spaced the same distance from each other as the bulbs. The tree of poles is a particularly expensive part, especially since its torsional rigidity is critical. In addition, the need to provide trees of different poles for each center distance prohibits designing the mechanism as a pre-assembled functional unit in factory independently of the cut-off modules. Architecture hardly favors delayed differentiation of the different models of a range of switchgear.

An objective of the invention is to produce an electrical apparatus for multipole breaking with independent polar cut-off modules, allowing the simultaneous operation of different modules. Another objective is to increase the modularity of a switchgear multipolar cut-off with independent polar cut-off modules, allowing low cost of changing the distance between poles. Another objective is to obtain an architecture which allows storage of standardized functional sub-assemblies, and their mounting last moment to meet customer needs.

• un support ;
• un mécanisme d'entraínement muni d'un arbre des pôles tourillonnant autour d'un premier axe géométrique fixe par rapport au support ;
• une pluralité de modules de coupure chaque module comportant
• une paire de contacts séparables comportant au moins un contact mobile ;
• une tige mobile solidaire du contact mobile ;
• un levier de transmission pivotant autour d'un deuxième axe géométrique parallèle au premier axe géométrique, ledit deuxième axe géométrique étant commun à l'ensemble des modules de coupure et fixe par rapport au support ;
• des moyens de liaison du levier de transmission à ladite tige ;

caractérisé en ce qu'il comporte en outre une bielle unique de liaison de l'arbre des pôles aux leviers de transmission des différents modules de coupure, la bielle étant articulée d'une part sur au moins deux manivelles coaxiales de l'arbre des pôles, définissant un troisième axe géométrique de pivotement parallèle au premier axe géométrique, et d'autre part sur des pivots assurant un pivotement de chaque levier de transmission par rapport à la bielle autour d'un quatrième axe géométrique de pivotement parallèle au premier axe géométrique et commun à l'ensemble des modules de coupure.According to the invention, these objectives are achieved by means of a multipole electrical switchgear comprising

• a support ;
• a drive mechanism provided with a pole shaft swiveling around a first geometric axis fixed relative to the support;
• a plurality of breaking modules each module comprising
• a pair of separable contacts comprising at least one movable contact;
• a movable rod secured to the movable contact;
• a transmission lever pivoting around a second geometric axis parallel to the first geometric axis, said second geometric axis being common to all of the cut-off modules and fixed relative to the support;
• means for connecting the transmission lever to said rod;

characterized in that it further comprises a single connecting rod connecting the pole shaft to the transmission levers of the different cut-off modules, the connecting rod being articulated on the one hand on at least two coaxial cranks of the pole shaft , defining a third geometric pivot axis parallel to the first geometric axis, and on the other hand on pivots ensuring a pivoting of each transmission lever relative to the connecting rod around a fourth geometric pivot axis parallel to the first geometric axis and common to all cut-off modules.

According to one embodiment, the movable rod is, in each module, linked to the connecting rod by through a pivoting connection around a fifth geometric axis parallel to the first geometric axis. This gives a simple geometric arrangement and advantageous, which ensures a geometric reference to a pole tree located at the height vacuum bulbs, while allowing the connecting rod to work in traction when contact closure. Preferably, the movable rod is linked to the connecting rod by through a pivoting connection around a fifth geometric axis, this in each module. The leverage effect allows in this configuration a reduction of the amplitude of the transmitted movement and a multiplication of the efforts, which is particularly favorable when the contacts have only a short opening and closing, as is the case in particular for vacuum ampoules.

Preferably, the connecting rod is arranged so as to be stressed in tension during the closing. The closure is the movement sequence or the forces transmitted by the connecting rod are the most important. By making the connecting rod work in tension in this sequence, we limits the deformations of the connecting rod. When opening, the connecting rod is stressed in compression but the efforts are relatively less important, so that the risks deformation of the rod out of its plane by buckling are discarded.

Preferably, the connecting rod comprises a sheet shaped so that its moment quadratic with respect to an axis perpendicular to a plane containing the third and the fourth axis, be high. The stiffness of the connecting rod in bending in a plane containing the third and fourth axes makes it possible to avoid any risk of delay in opening or closing of one of the pairs of contacts.

According to a preferred embodiment, the connecting rod comprises a sheet comprising two arms in vee each vee arm having a converging end supporting a bearing of articulation with one of the cranks of the pole shaft, and a divergent end, the divergent ends of the two vee arms being connected to each other by a base supporting articulation bearings with the levers of the cut-off modules.

According to one embodiment, the means of connecting the transmission lever to said rod have an insulating arm. This arrangement ensures insulation between the contacts and the mechanism, which is accessible to operators.

• un ressort de pression de contact ayant deux extrémités ;
• un premier organe de support d'une première extrémité du ressort, solidaire du levier ;
• un deuxième organe de support d'une deuxième extrémité du ressort, solidaire de la tige ;
• une liaison mécanique entre le premier organe et le levier, assurant la transmission intégrale du mouvement du levier dans le sens de la fermeture et n'assurant pas la transmission du mouvement dans le sens de l'ouverture.

According to one embodiment, the means for connecting the transmission lever to said rod comprise

• a contact pressure spring having two ends;
• a first support member for a first end of the spring, integral with the lever;
• a second support member for a second end of the spring, integral with the rod;
• a mechanical connection between the first member and the lever, ensuring the complete transmission of the movement of the lever in the closing direction and not ensuring the transmission of the movement in the opening direction.

Preferably, each cut-off module comprises a frame provided with support bearings ensuring the pivoting of the transmission lever around the second pivot axis. The cut-off modules can then be pre-assembled and tested in the factory, before their mounting with mechanism and connecting rod. This helps improve differentiation delayed.

Preferably, the connecting rod makes with the transmission levers an angle close to an angle straight, and the rod works in translation in a plane substantially parallel to the connecting rod. In in other words, the geometric plane defined by the second and fourth axes on the one hand and the geometric plane defined by the third and fourth axes on the other hand, make an angle of around 90 ° between them, while the rod is parallel to the plane containing the third and fourth axes.

The invention is particularly suited to the fact that each breaking module includes a vacuum interrupter constituting an enclosure in which the separable contacts are situated. However, it is possibly adaptable to other cutting principles, provided the opening and closing travel of the contacts is small.

• la figure 1 représente une vue éclatée d'un appareillage de coupure selon un mode de réalisation de l'invention, montrant en particulier un mécanisme d'entraínement et des modules de coupure ;
• la figure 2 représente une vue en coupe de l'appareillage de la figure 1, en position d'ouverture ;
• la figure 3 représente une vue en perspective d'une chaíne cinématique de transmission reliant le mécanisme aux modules de coupure ;
• la figure 4 représente une vue de côté de la chaíne cinématique, en position de fermeture.

Other advantages and characteristics will emerge more clearly from the description which follows, of a particular embodiment of the invention, given by way of nonlimiting example, and represented in the appended drawings in which:

• Figure 1 shows an exploded view of a switchgear according to an embodiment of the invention, showing in particular a drive mechanism and cutoff modules;
• 2 shows a sectional view of the apparatus of Figure 1, in the open position;
• Figure 3 shows a perspective view of a kinematic transmission chain connecting the mechanism to the cut-off modules;
• Figure 4 shows a side view of the drive train, in the closed position.

Referring to Figures 1 and 2, a three-pole switchgear 10 is composed of a drive mechanism 12 and three identical cut-off modules 14, 16, 18, arranged side by side on the same side of a partition 20 separating them from the mechanism drive 12. The partition 20 is constituted by a sheet comprising three windows 22, 24, 26 and rests on a second sheet 28 arranged at right angles and acting as a base. The partition 20 is at ground potential and provides electrical protection for people.

The drive mechanism 12 can be of any known type comprising a shaft of poles. It may for example be a mechanism of the type described in document EP-A- 0 222 645, fitted with an arming and closing sub-assembly comprising a spring closure, and an opening sub-assembly comprising an opening spring. The essential point in the context of the present invention is that the mechanism comprises a shaft of output, also says pole tree. In the exemplary embodiment, the mechanism 12 is fixed on a support frame 30 and provided with a pole shaft 32 supported by bearings 34 fixed to the chassis 30. The chassis is itself fixed to the partition 20.

As illustrated in Figure 3, the pole shaft 32 has two double cranks 36, 38 which pass through the chassis wall with lights and allow articulation between the shaft poles 32 and a transmission rod 40. The transmission rod 40 consists by a flat piece forming two double arms in v 42, 44, spaced from each other, and connected on the side of their divergent end by a base 46. Each v-shaped arm 42, 44 supports, at its converging end, a pair of legs 50, 52 provided with coaxial bores, forming bearings. The cranks 36, 38 also have coaxial bores forming bearings, so that a pivoting hinge-type connection is obtained between the cranks double 36, 38 of the pole shaft 32 and the connecting rod 40 by insertion of pins 54 in the corresponding bores of the double cranks 36, 38 and the double legs 50, 52. The base 46 supports three pairs of legs 60, 62, 64 provided with coaxial bores, forming bearings. These legs allow, by insertion of axes 66, a hinge-type connection with three double levers 70, 72, 74 belonging to the three polar modules 14, 16, 18 of the apparatus, which pass through the windows 22, 24, 26 of the partition 20.

The three cut-off modules being identical, only the module 18 will be described. As illustrated in Figure 2, the module 18 includes a vacuum interrupter 80 supported by a frame 82. The frame 82 is fixed to the wall 20 and to the base 28, so that the frame 30, the sheets 20, 28 and the frames 82 of the three poles together form a support 83 for the other parts of the apparatus. Two connection pads 84, 86, fixed to the frame 82, are intended for electrically connect the bulb 80 to a busbar (not shown). We designate here by the generic expression of vacuum interrupter a subset of known type, comprising a cylindrical body 88 forming an enclosure where a relative vacuum prevails and which contains a pair of separable contacts 90, 92 connected to connection pads 84, 86. The body 88 is itself divided into a median insulator section 94 of insulating material, a first metal end section constituting a first closing flange 96, and a second metal end section constituting a second closing flange 98. The contact 92 is fixed and connected to the second flange 98. The other contact 90 constitutes a axial end of a rod 100 movable in translation along its axis and passing through the body 88 of the bulb through an orifice in the flange 96. A sealing bellows 102 brazed onto the rod 100 and on the internal wall of the first flange 96, allows an axial movement of translation of the rod 100 and of the movable contact 90 relative to the fixed contact 92, while preserving the vacuum prevailing in the enclosure. The electrical connection of rod 100 to the clearance of bars is ensured by means of a flexible electrical connection 104, one end of which also constitutes connection area 84.

Outside the enclosure, the rod 100 is connected to the double lever 74, via an insulating arm 110. The insulating arm comprises a plastic body 112 overmolding on the one hand the head of a first threaded rod 114, and on the other hand the head of a second threaded rod 116 located in the axial extension of the first. The first one threaded rod 114 is screwed into a threaded blind hole located at the end of the rod 100 of the bulb 80. On the second threaded rod 116 is screwed a tubular adjusting nut 118. The nut 118 supports at one end a support plate 120 for one end of a contact pressure spring 122. The other end of the spring 122 relates to a second plate 124, which rests on a bar 126. The bar has a bore 128 forming a guide sleeve crossed by the tubular nut 118. The bar 126 journals freely in lateral axes 130 supported by the arms of the lever 74. The sheath of guide 128 authorizes both the translation of the nut 118 parallel to its axis and its free rotation. The nut 118 has a shoulder which comes to rest on the bar part 126 opposite the second plate 124. The two arms of the double lever 74 pivot around an axis 132 supported by the frame 82. The three cut-off modules 14, 16, 18 of the apparatus 10 being placed side by side, the pivot axes 132 of the levers 70, 72, 74 are aligned, and parallel to the pole shaft 32. The levers 70, 72, 74 are parallel.

Thus, the kinematic chain connecting the pole shaft 32 to the rods 100 of the three modules of cutoff 14, 16, 18 comprises a single connecting rod 40 for connection between the pole shaft 32 and the three double levers 70, 72, 74 of the cut-off modules, and is extended in each module by an insulator 112, one end of which slides in a swivel sleeve 128 relative to the double lever 70, 72, 74, and the other end is integral with the rod 100 of bulb 80. This kinematic chain makes it possible to define five geometric axes of parallel rotation: a first geometric axis 140 of pivoting of the pole shaft, a second geometric axis 142 for pivoting the levers 70, 72, 74, a third axis geometric 144 of pivoting of the connecting rod with respect to the cranks of the pole shaft, a fourth geometric axis 146 of pivoting of the connecting rod relative to the levers, and a fifth geometric axis 148 for pivoting the bars 126 with respect to the levers 70, 72, 74. The first axis 140 and the second axis 142 are both fixed relative to the support 83, the other axes being movable during the opening and closing sequences.

Strictly speaking, the movement imparted to the rod 100 of the bulb 80 by this mechanism in the absence of play between the moving parts would not be perfectly straight with respect to to the frame 82. However, the angle between the lever 70, 72, 74 and the rod 100 is still very close of the right angle, and the stroke of the rod 100 of the bulb between its open position and its closed position does not exceed a few millimeters, which corresponds to an angle of lever rotation not exceeding a few degrees, so that in the absence of play, the radial deflection of the rod 100 would be of the order of a hundredth of its axial stroke. In the embodiment described, this movement is absorbed by the games existing between the various elements of the kinematic chain, in particular at the axes 130, 132. However, if we wanted a larger stroke, it would be possible to guide the bar 126 in an oblong lever 90, 92, 94.

The kinematic chain works as follows. When the contacts are separated and the mechanism open, the kinematic chain is initially in the position shown in Figure 2. On closing, the closing spring of the mechanism 12 drives the pole shaft 32 counterclockwise, on a stroke more than 50 °. The rod 40 transmits this movement uniformly to the three levers double 70, 72, 74. In each of the cut-off modules, the double lever pivots in the clockwise around the axis 132, driving the bar 126 which compresses the spring 122 via the plate 124. The closing force is then transmitted by the spring 122 to the movable contact 90, via the trim 120, nut 118 and insulating arm 110. The kinematic chain is found in the closed position of Figure 4, the contacts being closed.

At the opening, the opening spring of the mechanism 12 drives the pole shaft in the clockwise, on a course of more than 50 °. The connecting rod 40 transmits this movement in a uniform manner with the three double levers 70, 72, 74. In each of the cut-off modules, the double lever pivots anticlockwise shows around the axis 132 in Figure 4, directly driving the bar 126, the nut 118, the insulating arm 110 and the rod 100 of the movable contact, until reaching the position Figure 2 open.

The single connecting rod 40 has a high quadratic moment relative to an axis perpendicular to the geometric plane containing the pivot axes of the connecting rod by relation to the pole shaft and to the double levers. Although the structure of the connecting rod has been lightened to reduce its mass, the base 46 preserves the desired rigidity. In others terms, the forces applied to the connecting rod in its plane are not likely to induce a notable bending of the connecting rod. Consequently, the connecting rod 40 gives the kinematic chain great rigidity, so that even if the efforts to be applied to the different bulbs are different, their movement will nevertheless be simultaneous. By construction, the tree of pole 32 is itself very rigid in torsion, so it is possible to space the two hinges joining the connecting rod 40 to the pole shaft 32 which contributes to further strengthen the rigidity of the kinematic chain.

The connecting rod is produced by cutting a sheet. The levers are also made of sheet metal. Electrical insulation is carried out in each cut-off module thanks to the insulating arms. It should be noted that the insulating part 112 of the arm is shaped as a skirt so as to ensure optimal insulation.

To modify the distance between the polar modules, simply change the connecting rod and, if necessary where appropriate, the wall 20, which are parts at very low cost. Each specific connecting rod has a base of different length and especially legs 60, 62, 64 in number and locations variables. On the other hand, the distance between the legs 50, 52 ensuring the hinge connection with the cranks of the pole shaft remains constant. Thus, the pole tree 32 remains identical whatever the distance between the polar modules, which means that the mechanism 12 can be pre-assembled in the factory and forms a functional unit for the entire range.

Likewise, the cut-off modules 14, 16, 18 are identical, whatever the center distance chosen. This allows to postpone the assembly of the equipment until the customer's choice is stopped.

Naturally, various modifications are possible. The number of modules is not limited to three: the invention also applies to dipolar devices, quadrupole, even hexapolar or octopolar. Levers 70, 72, 74 can be simple. The drive mechanism can be of any type: with closing springs and separate opening, to allow a closing, arming, opening sequence, closing, opening; with a single spring allowing closing and opening.

Claims (11)

Multipolar electrical switchgear comprising a support (83); a drive mechanism (12) provided with a pole shaft (32) swiveling around a first geometric axis (140) fixed relative to the support; a plurality of cut-off modules (14, 16, 18), each module comprising a pair of separable contacts (90, 92), comprising at least one movable contact (90); a movable rod (100) integral with the movable contact (90); a transmission lever (70, 72, 74), pivoting about a second geometric axis (142) parallel to the first geometric axis (140), said second geometric axis being common to all of the breaking modules (14, 16 , 18) and fixed relative to the support; means for connecting the transmission lever to said rod; characterized in that it further comprises a single connecting rod (40) connecting the pole shaft (32) to the transmission levers (70, 72, 74) of the different cut-off modules, the connecting rod (40) being articulated on the one hand on at least two cranks (36, 38) coaxial of the pole shaft (32), defining a third geometric axis (144) of pivoting parallel to the first geometric axis (140), and on the other hand on pivots (66) ensuring a pivoting of each transmission lever (70, 72, 74) relative to the connecting rod (40) around a fourth geometric axis (142) of pivoting parallel to the first geometric axis (140) and common to all the cut-off modules (14, 16, 18). Apparatus according to claim 1, characterized in that in each module, the movable rod (100) is linked to the connecting rod (40) by means of a pivoting connection around a fifth geometric axis (148) parallel to the first geometric axis (140). Apparatus according to claim 2, characterized in that in each module, the fifth pivot axis (148) is located between the second axis (142) and the fourth axis (146), closer to the second axis (142) than to the fourth (146). Apparatus according to claim 1, characterized in that the connecting rod (40) is arranged so as to be stressed in tension when the apparatus is closed. Apparatus according to claim 1, characterized in that the connecting rod (40) comprises a sheet shaped in such a way that its quadratic moment with respect to an axis perpendicular to a plane containing the third (144) and the fourth axis (146), either high, so that even if the forces to be applied to the different breaking modules (14, 16, 18) are different, their movement will nevertheless be simultaneous. Apparatus according to claim 1, characterized in that the connecting rod (40) comprises a sheet metal comprising two arms (42, 44) in vee, each arm in vee comprising a converging end supporting a hinge bearing (50, 52) with a cranks (36, 38) of the pole shaft (32), and a divergent end, the divergent ends of the two V-shaped arms (42, 44) being connected to each other by a base (46) supporting articulation bearings (60, 62, 64) with the levers (70, 72, 74) of the cut-off modules. Apparatus according to claim 1, characterized in that the means for connecting the transmission lever (70) to said rod (100) comprise an insulating arm (110). Apparatus according to claim 1, characterized in that the means for connecting the transmission lever (70, 72, 74) to said rod (100) comprise a contact pressure spring (122); a first support member (124) of a first end of the spring, integral with the lever (70, 72, 74); a second support member (120) of a second end of the spring (122), integral with the rod; a mechanical connection between the first support member (124) and the lever (70, 72, 74), such that the first support member is integral with the lever when the lever is moved in the direction of closing of the apparatus. Apparatus according to claim 1, characterized in that each switching module comprises a frame (82) provided with support bearings ensuring the pivoting of the transmission lever (70, 72, 74) around the second pivot axis (142). Apparatus according to claim 1, characterized in that the connecting rod makes with the transmission levers an angle close to the right angle and in that the rods move in translation substantially parallel to the connecting rod. Apparatus according to claim 1, characterized in that each switching module comprises a vacuum interrupter (80) constituting an enclosure in which the separable contacts (90, 92) are located.

Images