Current guide rod for vacuum circuit breakers

Abstract

Current guide rod (20) for a medium or high voltage vacuum circuit breaker (50), comprising: - a first rod element (1) extending along an axis (D); - a second rod element (2) that is joined with the first rod element (1); - a reinforcing sleeve (3) arranged radially around the first rod element (1), wherein the reinforcing sleeve (3) is compressed axially between the first rod element (1) and the second rod element (2).

Description

Technical field

[0001] The present invention relates to the field of medium- or high-voltage vacuum circuit breakers, also known as vacuum switches or vacuum circuit breakers. Vacuum circuit breakers are associated with actuators designed to interrupt the current in a part of the circuit. State of the art

[0002] As is generally known, a vacuum circuit breaker comprises two disconnect contacts arranged opposite each other. Each contact includes a current-conducting rod and a disc-shaped contact body formed integrally with the rod. The current-conducting rods are generally made of copper, as this metal has high electrical and thermal conductivity.

[0003] The contacts are arranged in a sheath that forms a fluid-tight enclosure under vacuum. The contacts can move relative to each other. When the contacts are in contact, current can flow from one contact to the other. When the contacts are separated, the current is interrupted.

[0004] To facilitate the integration of vacuum circuit breakers into medium- or high-voltage electrical distribution units, it is desirable to reduce their size, particularly their diameter. To maintain at least the same dielectric strength, the contact diameter must also be reduced to limit the electric field between the contacts and the outer casing to an acceptable level. Therefore, current-carrying rods with a reduced diameter are used. The mechanical stresses resulting from the impact when the contacts close are consequently higher, and the mechanical strength of the current-carrying rods can become problematic. Specifically, the current-carrying rods can deform and their length can decrease, leading to a loss of contact force.

[0005] Therefore, there is still a need for reinforced electrical contacts that can tolerate mechanical stresses higher than those of known solutions. Summary

[0006] For this purpose, the invention proposes a current guide rod for a medium or high voltage vacuum circuit breaker, comprising: - a first rod element that extends along an axis; - a second rod element that is combined with the first rod element; - a reinforcing sleeve arranged radially around the first rod element, wherein the reinforcing sleeve is compressed axially between the first rod element and the second rod element.

[0007] When a vacuum circuit breaker is in operation, the primary mechanical stresses experienced by the current guide rod are compressive stresses. The reinforcing sleeve, mounted in a compressed state, reinforces the first element. Over the rod's service life, creep of either the first or second element tends to increase the compressive load on the reinforcing sleeve. The reinforcing sleeve thus provides the rod with permanent reinforcement. This makes it possible to manufacture current guide rods with a small diameter but sufficient mechanical strength to ensure the desired durability.

[0008] The features listed in the following paragraphs can be implemented independently of each other or in any technically possible combination: The reinforcing sleeve is compressed in an axial direction, namely the direction of the axis of the current guide rod.

[0009] The current guide rod is designed to be attached to a contact body that extends transversely to the axis.

[0010] One of the first rod element and one of the second rod element are designed to be attached to the contact body.

[0011] According to one embodiment of the current guide rod, the reinforcing sleeve is cylindrical.

[0012] The reinforcing sleeve has the shape of a hollow cylinder.

[0013] The first rod element and the second rod element are coaxial.

[0014] The reinforcing sleeve and the first rod element are coaxial.

[0015] According to one embodiment of the current-guiding rod, the reinforcing sleeve, the first rod element and the second rod element are coaxial.

[0016] According to an exemplary embodiment of the current-carrying rod, the first rod element is made of copper.

[0017] The second rod element can also be made of copper.

[0018] According to an exemplary embodiment of the current guide rod, the reinforcing sleeve is made of stainless steel.

[0019] A stainless steel reinforcement sleeve is able to improve the mechanical strength of copper-based elements.

[0020] According to one embodiment of the current guide rod, the degree of axial compression of the reinforcement sleeve is between 0.1% and 5.0%.

[0021] According to one embodiment of the current guide rod, the first rod element comprises a shoulder that forms a stop for a first axial end of the reinforcement sleeve.

[0022] The first rod element comprises a first cylindrical part with a first diameter and a second cylindrical part with a second diameter that is larger than the first diameter, wherein the second cylindrical part comprises a first stop surface against which a first axial end of the reinforcing sleeve comes to rest.

[0023] Preferably, the outer edge of the shoulder has a widened shape.

[0024] This shape makes it possible to limit dielectric voltages.

[0025] The outer edge of the shoulder has a convex shape.

[0026] According to one embodiment, the reinforcing sleeve surrounds the first cylindrical part of the first rod element over the entire length of the reinforcing sleeve.

[0027] According to an exemplary embodiment of the current guide rod, the second rod element forms a stop for a second axial end of the reinforcement sleeve.

[0028] The second rod element includes a second stop surface against which a second axial end of the reinforcing sleeve comes to rest.

[0029] According to one embodiment of the current guide rod, the second rod element comprises a flat section that forms a receiving surface for receiving the second axial end of the reinforcement sleeve, wherein the flat section is extended in a radial direction by a flared section, the flared section being axially removed from the reinforcement sleeve.

[0030] As with the first rod element, this shape makes it possible to limit dielectric stresses.

[0031] The widened section of the second rod element has a convex shape.

[0032] According to one embodiment of the current guide rod, the thickness of the reinforcing sleeve is between 0.1 millimeters and 5.0 millimeters.

[0033] According to an exemplary embodiment, the ratio of the thickness of the reinforcing sleeve to the outer diameter of the reinforcing sleeve is between 0.01 and 0.1.

[0034] According to an exemplary implementation of the current-guiding rod, the reinforcing sleeve is in contact with a side surface of the first rod element.

[0035] According to one embodiment of the current guide rod, the reinforcing sleeve is radially tensioned.

[0036] According to one embodiment of the current-guiding rod, the reinforcing sleeve is in contact with a side surface of the second rod element.

[0037] According to one embodiment, the reinforcing sleeve is arranged radially around the first rod element and around the second rod element.

[0038] In one variant, there is a radial gap between the reinforcing sleeve and a side surface of the first rod element.

[0039] In this variant of the current guide rod, the radial gap can be between 0.5% and 2% of the diameter of the reinforcement sleeve.

[0040] According to one embodiment, the axial length of the reinforcing sleeve is between 50% and 80% of the axial length of the first rod element.

[0041] According to an exemplary embodiment of the current-guiding rod, the axial length of the reinforcing sleeve is between 5% and 50% of the total axial length of the rod.

[0042] According to one embodiment, the first rod element and the second rod element are attached to each other by soldering.

[0043] According to an exemplary embodiment, an axial end of the first rod element terminates in a pin and an axial end of the second rod element comprises a housing designed to receive the pin of the first rod element.

[0044] As a variant, an axial end of the second rod element terminates in a pin and an axial end of the first rod element comprises a housing designed to receive the pin of the second rod element.

[0045] The pen and the casing have complementary shapes.

[0046] The disclosure also relates to a method for assembling a current-carrying rod, as described above. The assembly method comprises the following steps: - Providing an initial rod element, - Providing a second rod element, - Providing a reinforcement sleeve, - Inserting the first rod element into the reinforcement sleeve, - axial compression of the reinforcing sleeve between the first rod element and the second rod element, - Attaching the first rod element and the second rod element to each other.

[0047] The invention also relates to an electrical current breaker contact for a medium or high voltage vacuum circuit breaker, comprising: - a current-carrying rod, as described above, - a contact body attached to the current guide rod, the contact body extending transversely to the axis.

[0048] The invention also relates to a medium- or high-voltage vacuum circuit breaker, comprising: - a first circuit breaker contact, as described above, - a second current breaker contact as described above, wherein at least one of the first contact and the second contact is configured to be moved along the axis between a position referred to as open, in which the contacts are separated from each other, and a position referred to as closed, in which the contacts are in contact with each other, so that electric current may flow between the first contact and the second contact. Brief description of the drawings

[0049] Further features, details and advantages will become apparent from reading the following detailed description and from analyzing the accompanying drawings, which: Fig. 1 a schematic side view of a medium-voltage or high-voltage vacuum circuit breaker is, Fig. 2 a side view in cross-section of a medium-voltage or high-voltage vacuum circuit breaker according to an embodiment of the invention, Fig. 3 A side view of a current guide rod of the vacuum circuit breaker of Fig. 2 is, Fig. 4 a side view in cross-section of the current-carrying rod of Fig. 3 is, Fig. Figure 5 is a schematic side view showing the current-carrying rod of Fig. 4 shows in detail, Fig. 6 a schematic side view of a current guide rod according to one design variant is, Fig. 7 a schematic side view of a current guide rod according to a further embodiment variant is, Fig. Figure 8 is a perspective view that schematically shows different steps of a procedure for assembling the current-carrying rod of Fig. 2 to Fig. 4 indicates. Description of the embodiments:

[0050] To facilitate reading the figures, the various elements are not necessarily drawn to scale. In these figures, identical elements bear the same reference symbols. Certain elements or parameters may be indexed, i.e., designated, for example, as the first element or the second element, or as the first parameter and the second parameter, and so on. The purpose of this indexing is to distinguish between elements or parameters that are similar but not identical. This indexing does not imply the priority of one element or parameter over another, and the designations may be interchangeable. When it is specified that a subsystem includes a given element, this does not preclude the presence of other elements in that subsystem. Likewise, when it is specified that a subsystem includes a given element, it is understood that the subsystem includes at least that element.

[0051] In the various figures, the axes X, Y, Z denote the three directions in space, so that the viewpoint for each figure can be identified.

[0052] Fig. Figure 1 represents a medium- or high-voltage vacuum circuit breaker 50. The vacuum circuit breaker 50 comprises: - a first current breaker contact 30a, - a second circuit breaker contact 30b.

[0053] At least one of the first contact 30a and the second contact 30b is designed to be moved along the axis D between a position O, designated as open, in which the contacts 30a, 30b are separated from each other, and a position F, designated as closed, in which the contacts 30a, 30b are in contact with each other, so that an electric current can flow between the first contact 30a and the second contact 30b.

[0054] The vacuum circuit breaker 50 forms part of a medium or high voltage power switching device, such as a circuit breaker or a disconnect switch.

[0055] When the circuit breaker contacts 30a and 30b are in contact with each other, an electric current can flow. In part A of Fig. The symbol C indicates the passage of electric current.

[0056] When contacts 30a and 30b are separated, the electric current flow is generally interrupted after a transition period during which an electric arc is present between the two contacts 30a and 30b. In part B of Fig. 1 The electrical contacts are separated by a distance indicated by the symbol g, and the flow of electric current from one contact to the other is interrupted.

[0057] The contacts 30a, 30b are arranged in an insulating sheath 40, which forms a fluid-tight enclosure that is placed under vacuum.

[0058] A protective shield 35 of cylindrical shape, which is in Fig. The contact 30a, 30b, which is visible in Figure 2, is located inside the insulating sheath 40. The contacts 30a, 30b are located inside the volume defined by the protective shield 35. The protective shield 35 prevents any metallic particles that detach from the contacts during the generation of an electric arc from settling on the inner surface of the insulating sheath 40.

[0059] Each contact 30a, 30b comprises a current guide rod 20a, 20b extending along an axis D, and a contact body 10a, 10b attached to the current guide rod 20a, 20b.

[0060] Each contact body 10a, 10b has the general shape of a disk and extends transversely to the axis D.

[0061] When the vacuum circuit breaker 50 closes, an impact occurs between the two contacts 30a, 30b. This impact induces high mechanical stresses in the contacts, particularly in the current guides 20a, 20b. The repeated impacts from successive uses of the vacuum circuit breaker tend to permanently deform the current guides 20a, 20b. These deformations tend to reduce the length of these guides, and this reduces the pressure between the contact bodies 10a, 10b when they are in the conducting position. The risk of deformation is particularly high when the diameter of the rods is small in order to reduce the size of the vacuum circuit breaker, especially the radial size.

[0062] It is therefore desirable to increase the mechanical strength of the current-carrying rods 20a, 20b without increasing their diameter and without reducing their electrical conductivity.

[0063] Fig. Figure 3 represents an embodiment of a current guide rod 20 for a medium or high voltage vacuum circuit breaker 50. The current guide rod 20 comprises: - a first rod element 1 extending along an axis D; - a second rod element 2, which is connected to the first rod element 1; - a reinforcing sleeve 3 arranged radially around the first rod element 1, wherein the reinforcing sleeve 3 is compressed axially between the first rod element 1 and the second rod element 2.

[0064] When a vacuum circuit breaker is operating, the main mechanical stresses experienced by the current guide rod are compressive stresses. The reinforcing sleeve 3, mounted in an axially compressed state, reinforces the first rod element 1. Over the service life of the rod 20, any creep of the first element 1 or the second element 2 tends to increase the compressive load on the reinforcing sleeve 3. The reinforcing sleeve 3 is thus able to provide the rod 20 with permanent reinforcement. It is therefore possible to manufacture current guide rods with a small diameter but sufficient mechanical strength to ensure that the product has the desired durability.

[0065] The reinforcing sleeve 3 is compressed in an axial direction, namely in the direction of the axis D of the current guide rod 20.

[0066] The reinforcing sleeve 3 surrounds the first rod element 1 over at least part of the length of the first rod element 1.

[0067] The length of the first rod element 1 refers to the dimension measured along the axis D of the first rod element 1.

[0068] At least part of the first rod element 1 is located inside the reinforcing sleeve 3.

[0069] The reinforcing sleeve 3 is located radially outside the first rod element 1.

[0070] The reinforcing sleeve 3 is compressed in the direction of the axis D between the first rod element 1 and the second rod element 2.

[0071] The current-carrying rod 20 is designed to carry an electric current. The first rod element 1 and the second rod element 2 are both designed to carry an electric current.

[0072] The current guide rod 20 is designed to be attached to a contact body 10 which extends transversely to the axis D.

[0073] The contact body 10 has the general shape of a disc. It may have slots extending from the outer circumference of the disc to a radially central area. These slots allow the electric arc to rotate during current interruption phases.

[0074] One of the first rod element 1 and the second rod element 2 is designed to be attached to the contact body 10.

[0075] Rod 20 has the overall shape of a cylinder of revolution with axis D. Therefore, the first rod element 1 and the second rod element 2 also have the overall shape of a cylinder of revolution with axis D.

[0076] The reinforcing sleeve 3 is cylindrical.

[0077] The reinforcing sleeve 3 has the shape of a hollow cylinder.

[0078] The reinforcement sleeve 3 exhibits rotational symmetry about its axis D.

[0079] The first rod element 1 and the second rod element 2 are coaxial.

[0080] The reinforcing sleeve 3 and the first rod element 1 are coaxial.

[0081] According to the illustrated embodiment of the current-guiding rod 20, the reinforcing sleeve 3, the first rod element 1 and the second rod element 2 are coaxial.

[0082] The first rod element 1 is made of copper.

[0083] The second rod element 2 is also made of copper.

[0084] The use of copper to form the first element 1 and the second element 2 of the rod makes it possible to ensure high electrical and thermal conductivity.

[0085] In this case, the reinforcing sleeve 3 is made of stainless steel. For example, the reinforcing sleeve is made of AISI 316L stainless steel. A stainless steel reinforcing sleeve is able to improve the mechanical strength of the copper elements.

[0086] According to one embodiment of the current guide rod 20, the degree of axial compression of the reinforcing sleeve 3 is between 0.1% and 5.0%.

[0087] Due to the axial compression exerted on the reinforcing sleeve 3, the length of the reinforcing sleeve 3 when it is mounted on the guide rod 20 is shorter than when it is in its resting state.

[0088] The rest state is the unmounted state, that is, when no tension is exerted on the reinforcing sleeve 3. "No external tension" means no force other than gravity and the reaction force exerted by the support on which the reinforcing sleeve rests.

[0089] The degree of axial compression of the reinforcing sleeve 3 is defined by the difference between the length L0 of the reinforcing sleeve 3 in its rest state and the length L3 of the reinforcing sleeve 3 after it has been compressed, divided by the length L0 of the reinforcing sleeve 3 in its rest state.

[0090] The lengths L3 and L0 are measured in the axial direction D of the reinforcement sleeve 3.

[0091] For example, the reinforcing sleeve 3 can have a length L0 of 50 millimeters in its unmounted, resting state. If the length L3 in the mounted and compressed state is 49.5 millimeters, then the compression ratio is 1%.

[0092] As in Fig. 3 and Fig. As shown in Figure 4, the first rod element 1 includes a shoulder 4 which forms a stop for a first axial end 5 of the reinforcing sleeve 3.

[0093] The first rod element 1 comprises a first cylindrical part 7 with a first diameter d1 and a second cylindrical part 8 with a second diameter d2, which is larger than the first diameter d1. The second cylindrical part 8 comprises a first stop surface 11 against which a first axial end 5 of the reinforcing sleeve 3 abuts.

[0094] In the Fig. In the example shown in Figure 4, the outer edge of shoulder 4 has a widened shape.

[0095] This shape makes it possible to limit dielectric voltages.

[0096] More precisely, the outer edge of shoulder 4 has a convex shape here.

[0097] According to the Fig. In the embodiment shown in Figures 2 to 6, the reinforcing sleeve 3 surrounds the first cylindrical part 7 of the first rod element 1 over the entire length of the reinforcing sleeve 3.

[0098] The second rod element 2 forms a stop for a second axial end 6 of the reinforcing sleeve 3.

[0099] The second rod element 2 includes a second stop surface 12, against which a second axial end 6 of the reinforcing sleeve 3 comes to rest.

[0100] As in Fig. As shown in Figure 4, the second rod element 2 comprises a flat section 14, which forms a receiving surface for receiving the second axial end 6 of the reinforcing sleeve 3. The flat section 14 is extended in a radial direction by a flared section 15. The flared section 15 is located axially D away from the reinforcing sleeve 3.

[0101] In other words, the widened section 15 is offset along axis D from the reinforcing sleeve 3.

[0102] As is the case with the first rod element 1, this shape with a flared edge makes it possible to limit dielectric stresses.

[0103] The widened section 15 of the second rod element 2 has a convex shape here.

[0104] The thickness e of the reinforcement sleeve 3 is between 0.1 millimeters and 5.0 millimeters.

[0105] According to an exemplary embodiment, the ratio of the thickness e of the reinforcing sleeve 3 to an outer diameter d3 of the reinforcing sleeve 3 is between 0.01 and 0.1.

[0106] The ratio of thickness e to outer diameter d3 refers to the result of the quotient of thickness e and outer diameter d3.

[0107] If this ratio has a value of 0.05, for example, the thickness e is equal to 0.05 times the outer diameter d3. Therefore, with an outer diameter of 20 millimeters, the thickness e of the reinforcing sleeve is equal to 1 millimeter.

[0108] According to the in the Fig. 3 to Fig. In the embodiments shown in Figure 5, the reinforcing sleeve 3 is in contact with a side surface 9 of the first rod element 1.

[0109] The reinforcing sleeve 3 can be radially tensioned.

[0110] In other words, the first rod element 1 can exert a radial thrust directed towards the outside of the reinforcing sleeve 3.

[0111] Fig. Figure 5 illustrates this aspect in detail. Arrows Fa1 and Fa2 schematically indicate the axial stresses exerted on the reinforcing sleeve 3. Arrow Fa1 corresponds to the force exerted on the reinforcing sleeve 3 by the first rod element 1, and arrow Fa2 corresponds to the force exerted by the second rod element 2.

[0112] The arrows Fr schematically indicate the radial stresses exerted by the first rod element 1 on the reinforcing sleeve 3.

[0113] During the service life of the vacuum circuit breaker, repeated application of mechanical compressive stresses to the current guide rods tends to deform these rods. Thus, a rod element that was perfectly cylindrical before use tends to gradually decrease in length and increase in diameter, at least over a portion of its length.

[0114] In Fig. The areas designated by symbol 21 correspond to areas where there is still a certain gap between the inner side surface 13 of the reinforcing sleeve 3 and the outer side surface 9 of the first rod element 1. The area designated by symbol 22 corresponds to an area where the outer side surface 9 of the first rod element 1 is in contact with the inner surface 13 of the reinforcing sleeve 3. In this area, the first rod element 1 exerts a radial stress on the reinforcing sleeve 3.

[0115] In Fig. In Figure 5, the size of the areas 21 and the size of the deformation of the first rod element 1 are exaggerated to facilitate the interpretation of the figure.

[0116] The reinforcing sleeve 3 thus counteracts the local increase in the diameter of the first rod element 1 and limits its radial deformation, in addition to limiting its axial deformation.

[0117] Fig. Figure 7 represents another embodiment of the current guide rod 20.

[0118] According to this embodiment, the reinforcing sleeve 3 is in contact with a side surface 19 of the second rod element 2.

[0119] The reinforcing sleeve 3 is arranged radially around the first rod element 1 and around the second rod element 2.

[0120] In other words, part of the first rod element 1 and part of the second rod element 2 extend inside the volume bounded by the inner surface 13 of the reinforcing sleeve 3.

[0121] In this embodiment, the transition point 16 between the first rod element 1 and the second rod element 2 is located inside the reinforcing sleeve 3.

[0122] The transition point refers to the contact area between the first element 1 and the second element 2.

[0123] According to the in Fig. In the variant shown in Figure 6, there is a radial gap j between the reinforcing sleeve 3 and a side surface 9 of the first rod element 1.

[0124] In this variant of the current guide rod 20, the radial gap j can be between 0.5% and 2% of a diameter d3 of the reinforcement sleeve 3.

[0125] The reinforcing sleeve 3 can only surround the first rod element 1 over a part of the length of the first rod element 1.

[0126] For example, the axial length L3 of the reinforcing sleeve 3 lies between 50% and 80% of the axial length L1 of the first rod element 1.

[0127] According to an exemplary embodiment of the current-guiding rod 20, the axial length L3 of the reinforcing sleeve 3 lies between 5% and 50% of the total axial length of the rod 20.

[0128] The first rod element 1 and the second rod element 2 are, for example, attached by soldering.

[0129] An axial end of the first rod element 1 terminates in a pin 17, and an axial end of the second rod element 2 comprises a housing 18 configured to receive the pin 17 of the first rod element 1. This type of embodiment is described in Fig. 4 shown.

[0130] As a variant, which has not been shown, an axial end of the second rod element 2 terminates in a pin and an axial end of the first rod element 1 comprises a housing designed to receive the pin of the second rod element 2.

[0131] The pin 17 and the housing 18 have complementary shapes.

[0132] The solder material can at least partially fill the space between pin 17 and housing 18. Likewise, the solder material forms a bonding layer that connects the facing surfaces of the first element 1 and the second element 2.

[0133] The Fig. 5, Fig. 6 and Fig. Figure 7 does not show the pen and the casing.

[0134] Fig. Figure 8 describes a method for assembling a current guide rod 20 as described above.

[0135] The assembly procedure includes the following steps: - Providing a first rod element 1, - Providing a second rod element 2, - Providing a reinforcement sleeve 3, - Inserting the first rod element 1 into the reinforcing sleeve 3, - axial compression of the reinforcing sleeve 3 between the first rod element 1 and the second rod element 2, - Attaching the first rod element 1 and the second rod element 2 to each other.

[0136] This results in a current guide rod 20.

[0137] A contact body is then attached to the current guide rod 20 to form a current breaker contact 30a.

[0138] The vacuum circuit breaker includes two contacts 30a, 30b.

[0139] Each current breaker contact 30a, 30b for a medium or high voltage vacuum circuit breaker 50 includes: - a current-carrying rod 20a, 20b, as described above, - a contact body 10a, 10b which is attached to the current guide rod 20, wherein the contact body 10a, 10b extends transversely to the axis D.

[0140] According to one embodiment, which is not shown, the inner diameter of the reinforcing sleeve 3 in the rest state is smaller than the outer diameter of the section of the rod element that it surrounds.

[0141] In other words, the reinforcing sleeve 3 is in this case mounted as an interference fit on the rod element(s) that it surrounds.

[0142] The assembly is achieved, for example, by heating the reinforcing sleeve before inserting the rod element, whereby the temperature increase allows the inner diameter of the reinforcing sleeve 3 to be temporarily increased. Alternatively, the rod element can be cooled so that its diameter decreases, making it possible to insert it.

[0143] In the example of Fig. 2 Each of the two electrical contacts 30a, 30b of the vacuum circuit breaker 50 comprises a guide rod 20a, 20b, each of which comprises a reinforcing sleeve 3a, 3b.

[0144] The medium or high voltage vacuum circuit breaker 50 thus comprises: - a first circuit breaker contact 30a, as described above, - a second current breaker contact 30b as described above, wherein at least one of the first contact 30a and the second contact 30b is configured to move along the axis D between a position O designated as open, in which the contacts 30a, 30b are separated from each other, and a position F designated as closed, in which the contacts 30a, 30b are in contact with each other, so that electric current can flow between the first contact 30a and the second contact 30b.

[0145] According to one embodiment variant, which has not been shown, only one of the two electrical contacts comprises a guide rod 20 which includes a reinforcing sleeve 3.

[0146] According to the example of Fig. 2. Contact 2a is a movable contact and contact 2b is a fixed contact.

[0147] According to one variant, which was not shown, contact 2a and contact 2b are both movable contacts.

Claims

[1] Current-carrying rod (20) for a medium- or high-voltage vacuum circuit breaker (50), comprising: - a first rod element (1) extending along an axis (D); - a second rod element (2) which is united with the first rod element (1); - a reinforcing sleeve (3) arranged radially around the first rod element (1), wherein the reinforcing sleeve (3) is axially compressed between the first rod element (1) and the second rod element (2). [2] Current-carrying rod (20) according to claim 1, wherein the reinforcing sleeve (3) is cylindrical. [3] Current-carrying rod (20) according to claim 1 or 2, wherein the reinforcing sleeve (3), the first rod element (1) and the second rod element (2) are coaxial. [4] Current-carrying rod (20) according to one of the preceding claims, wherein: - the first rod element (1) is made of copper, - the second rod element (2) is made of copper, - the reinforcement sleeve (3) is made of stainless steel. [5] Current-carrying rod (20) according to one of the preceding claims, wherein a degree of axial compression of the reinforcing sleeve (3) is between 0.1% and 5%. [6] Current-carrying rod (20) according to one of the preceding claims, wherein the first rod element (1) comprises a shoulder (4) forming a stop for a first axial end (5) of the reinforcing sleeve (3). [7] Current-carrying rod (20) according to the preceding claim, wherein an outer edge of the shoulder (4) has a widened shape. [8] Current-carrying rod (20) according to one of the preceding claims, wherein the second rod element (2) forms a stop for a second axial end (6) of the reinforcing sleeve (3). [9] Current-carrying rod (20) according to the preceding claim, wherein the second rod element (2) comprises a planar portion (14) forming a receiving surface for receiving the second axial end (6) of the reinforcing sleeve (3), wherein the planar portion (14) is extended in a radial direction by a widened portion (15), wherein the widened portion (15) is remote from the reinforcing sleeve (3) in an axial direction. [10] Current-carrying rod (20) according to one of the preceding claims, wherein the thickness (e) of the reinforcing sleeve (3) is between 0.1 millimeters and 5.0 millimeters, and wherein a ratio of the thickness (e) of the reinforcing sleeve (3) to an outer diameter (d3) of the reinforcing sleeve (3) is between 0.01 and 0.

1. [11] Current-carrying rod (20) according to one of the preceding claims, wherein the reinforcing sleeve (3) is in contact with a side surface (9) of the first rod element (1). [12] Current-carrying rod (20) according to one of the preceding claims, wherein the reinforcing sleeve (3) is radially tensioned. [13] Current-carrying rod (20) according to one of the preceding claims, wherein the reinforcing sleeve (3) is in contact with a side surface (19) of the second rod element (2). [14] Current-carrying rod (20) according to one of claims 1 to 10, wherein there is a radial gap (j) between the reinforcing sleeve (3) and a side surface (9) of the first rod element (1), and wherein the radial gap (j) is between 0.5% and 2% of a diameter (d3) of the reinforcing sleeve (3). [15] Current-carrying rod (20) according to one of the preceding claims, wherein: - an axial length (L3) of the reinforcement sleeve (3) is between 50% and 80% of an axial length (L1) of the first rod element (1), and - an axial length (L3) of the reinforcement sleeve (3) is between 5% and 50% of a total axial length (L20) of the rod (20). [16] Circuit breaker contact (30a, 30b) for a medium or high voltage vacuum circuit breaker (50), comprising: - a current-carrying rod (20a, 20b) according to one of claims 1 to 15, - a contact body (10a, 10b) which is fastened to the current-carrying rod (20), the contact body (10a, 10b) extending transversely to the axis (D). [17] Medium or high voltage vacuum circuit breaker (50), comprising: - a first circuit breaker contact (30a) according to the preceding claim, - a second circuit breaker contact (30b) according to the preceding claim, wherein at least one of the first contact (30a) and the second contact (30b) is adapted to be moved along the axis (D) between a position (O) designated as open, in which the contacts (30a, 30b) are separated from one another, and a position (F) designated as closed, in which the contacts (30a, 30b) are in contact with one another, in order to allow electrical current to flow between the first contact (30a) and the second contact (30b).

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