Contact support assembly, vacuum interrupter assembly, and vacuum circuit breaker

Abstract

The present utility model relates to a contact support assembly, a vacuum arc extinguishing assembly and a vacuum circuit breaker. The contact support assembly includes: a support (41); a contact spring (45), supported by the support (41); a movable member (47), connected to and moving along with the contact spring (45) and having a wear indication portion (472); and a linkage (42), connected to the movable member (47) and having a contact connection end (421), wherein relative positions of the movable member (47) and the linkage (42) are configured such that during closing of contacts, a position change of the wear indication portion (472) is identifiable when one of the contacts reaches a predetermined wear thickness value.

Description

TECHNICAL FIELD

[0001] The present utility model relates to the technical field of control and protection of electrical equipment, and relates in particular to a contact support assembly, a vacuum arc extinguishing assembly and a vacuum circuit breaker.BACKGROUND

[0002] A vacuum arc extinguishing chamber, also known as a vacuum switch tube, is a core component of a medium-high voltage power switch. The main function of the vacuum arc extinguishing chamber is to quickly extinguish an arc and suppress a current by means of the excellent vacuum insulation properties of the tube after a power supply of a medium-high voltage circuit is cut off, so as to avoid occurrence of incidents and accidents. During the processes of opening and closing movable and stationary contacts in the vacuum arc extinguishing chamber, various phenomena such as formation of a molten metal bridge, generation of an electric arc and spark discharge occur at a gap between the contacts, causing metal transfer, spatter and vaporization of a contact material, thereby resulting in a contact material loss and contact deformation, which are collectively referred to as contact wear. Contact wear directly affects the service life of electrical equipment, and even affects the safety of the electrical equipment. Therefore, an effective means is needed to transmit contact wear information to an operator without delay.

[0003] One known solution is to form a wear indicator on a movable contact, so as to indicate to the operator the degree of contact wear through a position change of the wear indicator after the contacts are closed. However, the disadvantage of this scheme is that the vacuum arc extinguishing chamber needs to be configured as a closed assembly, and thus the operator is generally unable to directly observe the movable contact to check the degree of contact wear in actual practice. As such, a series of supplementary components such as a sensor may be required, which increases the structural complexity of a circuit breaker and is not beneficial to equipment installation and maintenance. Therefore, there is a need for a scheme that enables direct detection of the degree of contact wear and simplifies the structure in the industry.SUMMARY

[0004] The present utility model aims to provide a contact support assembly capable of solving at least part of the above technical problems.

[0005] The present utility model further aims to provide a vacuum arc extinguishing assembly employing the above improved contact support assembly.

[0006] The present utility model further aims to provide a vacuum circuit breaker employing the above improved vacuum arc extinguishing assembly.

[0007] According to one aspect of the present utility model, provided is a contact support assembly, comprising: a support; a contact spring, supported by the support; a movable member, connected to and moving along with the contact spring and having a wear indication portion; and a linkage, connected to the movable member and having a contact connection end, wherein relative positions of the movable member and the linkage are configured such that during closing of contacts, a position change of the wear indication portion is identifiable when one of the contacts reaches a predetermined wear thickness value.

[0008] In some embodiments, the linkage passes through the movable member. The movable member is adjustably installed on the linkage in the axial direction thereof relative to the linkage.

[0009] In some embodiments, the linkage passes through the support and the contact spring, and is connected to the movable member. A flange is formed at one end of the linkage on a side of the support facing away from the contact spring. The other end of the linkage extends out of the movable member and serves as the contact connection end.

[0010] In some embodiments, an insulation sleeve is sleeved on the linkage. The insulation sleeve passes through the contact spring and the support.

[0011] In some embodiments, a first insulation pad is sleeved on the linkage, and the first insulation pad is located between the support and the flange; and / or a second insulation pad is sleeved on the linkage, and the second insulation pad is arranged on a side surface of the movable member facing away from the support.

[0012] In some embodiments, the contact spring is accommodated in a sleeve supported by the support. The wear indication portion is configured such that during closing of contacts, the wear indication portion is capable of moving outside of the sleeve tube to be identified when one of the contacts reaches the predetermined wear thickness value.

[0013] In some embodiments, the movable member is supported by the contact spring. The wear indication portion is an indication line formed on the outer circumferential surface of the movable member.

[0014] In some embodiments, the movable member further has an installation indication portion. The installation indication portion is located away from the support relative to the wear indication portion.

[0015] According to another aspect of the present utility model, provided is a vacuum arc extinguishing assembly, comprising: a vacuum arc extinguishing chamber provided with a movable contact and a stationary contact capable of moving relative to each other; and a contact support assembly, connected to the movable contact, wherein the contact support assembly is the aforementioned contact support assembly, and the contact connection end of the linkage is connected to the movable contact.

[0016] According to yet another aspect of the present utility model, provided is a vacuum circuit breaker, comprising: a housing; a vacuum arc extinguishing assembly, accommodated in the housing; and an operating mechanism, connected to the vacuum arc extinguishing assembly, wherein the vacuum arc extinguishing assembly is the aforementioned vacuum arc extinguishing assembly, and the operating mechanism is connected to the support of the contact support assembly.

[0017] Part of the other features and advantages of the present utility model would be obvious to a person skilled in the art after reading the present application, and the rest will be described in the following detailed description with reference to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments of the present utility model are described in detail below with reference to the accompanying drawings: FIG. 1 is a partial schematic view of a vacuum circuit breaker according to an embodiment of the present utility model. FIG. 2 is a schematic view of a contact support assembly according to an embodiment of the present utility model. FIG. 3 is a schematic exploded view of a contact support assembly according to an embodiment of the present utility model. FIG. 4 is a cross-sectional view of a contact support assembly according to an embodiment of the present utility model, illustrating that when contacts are in a closed state, an installation indication portion of a movable member is identifiable while a wear indication portion of the movable member is not identifiable yet. FIG. 5 is a cross-sectional view of a contact support assembly according to an embodiment of the present utility model, illustrating that when contacts are in a closed state, a wear indication portion of a movable member is identifiable. Description of the reference numerals:

[0019] 1, vacuum circuit breaker; 2, coil; 3, vacuum arc extinguishing chamber; 31, first connection terminal; 32, second connection terminal; 33, flexible connector; 4, contact support assembly; 40, connection shaft; 41, support; 42, linkage; 421, contact connection end; 422, flange; 43, first insulation pad; 44, insulation sleeve; 45, contact spring; 451, spring plate; 46, sleeve tube; 47, movable member; 471, installation indication portion; 472, wear indication portion; 48, second insulation pad; and 5, linkage assembly.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Schematic schemes of a contact support assembly, a vacuum arc extinguishing assembly and a vacuum circuit breaker disclosed in the present utility model are described below in detail with reference to the accompanying drawings. Although providing the accompanying drawings is to present some implementations of the present utility model, the accompanying drawings do not need to be drawn according to the size of the specific implementation schemes, and certain features can be enlarged, removed, or locally exploded to better illustrate and explain the disclosure of the present utility model. Part of members in the accompanying drawings can be positionally adjusted according to actual requirements without affecting the technical effect. In the description, the term "in the accompanying drawings" or similar terms do not necessary refer to all of the accompanying drawings or examples.

[0021] Some directional terms used in the following to describe the accompanying drawings, such as "in", "out", "upper", and "lower," and other directional terms are construed as having normal meanings thereof and refer to those directions involved when the accompanying drawings are viewed normally. Unless otherwise specified, the directional terms in the description are substantially in accord with conventional directions understood by those skilled in the art.

[0022] The terms "first," "first one," "second," and "second one" and similar terms used in the present utility model do not indicate any sequence, number, or importance in the present utility model, and are used only to distinguish one component from other components.

[0023] FIG. 1 shows a schematic view of a vacuum circuit breaker 1 according to an embodiment of the present utility model. As shown, a stationary contact (not shown) within a vacuum arc extinguishing chamber 3 of the vacuum circuit breaker 1 is connected to a first connection terminal 31, and a movable contact (not shown) within the vacuum arc extinguishing chamber 3 is connected to a second connection terminal 32 through a flexible connector 33. A coil 2, such as a CT coil, is arranged at the first connection terminal 31. A contact support assembly 4 is connected to the movable contact of the vacuum arc extinguishing chamber 3. An opening / closing operating mechanism (not shown) of the vacuum circuit breaker 1 is connected to and controls the movement of the contact support assembly 4 by means of a linkage assembly 5, thereby driving the movable contact to be connected to or disconnected from the stationary contact. The vacuum arc extinguishing chamber 3 and the contact support assembly 4 can be placed in, for example, an integral housing (not shown).

[0024] FIG. 2 and FIG. 3 illustrate an example of the contact support assembly 4. As shown, in the contact support assembly 4, a connection shaft 40 is installed at a support 41. The support 41 is shown in an inverted U-shape, and the connection shaft 40 is inserted into two opposite side walls of the support 41. The connection shaft 40 is configured to be pivotally connected to a pull rod of the linkage assembly 5. In other embodiments not shown, the support 41 can have other configurations. For example, the connection shaft separable from the support may be omitted, and the support is integrally formed with a protruding cylindrical shaft for connecting the pull rod of the linkage assembly 5.

[0025] A sleeve tube 46 is supported on the support 41. A contact spring 45 is arranged within the sleeve tube 46. The contact spring 45 supports a movable member 47, and provides to the movable member 47 a pushing force in a direction that faces away from the support 41 (i.e., a direction pointing to the movable contact within the vacuum arc extinguishing chamber). The linkage 42 passes through the support 41, the contact spring 45 and the movable member 47, and the linkage 42 is connected to the movable member 47. After assembly, the linkage 42 is not movable relative to the movable member 47, or at least the movable member 47 cannot move in the axial direction of the linkage 42, so that the movement of the movable member 47 (under the pushing force of the contact spring 45) drives the linkage 42 to move synchronously. As shown in the figures, the contact spring 45 consists of a plurality of spring plates 451 which are stacked in the axial direction of the sleeve tube 46. In other embodiments not shown, a coil spring can be used as the contact spring, or a spring element of another configuration can be used. One end of the linage 42 extends out of a side of the support 41 facing away from the sleeve tube 46, and is provided with a flange 422. The dimension of the flange 422 is larger than that of an opening of the support 41 through which the linkage 42 passes, thereby preventing detachment of the linkage 42 from the support 41 during movement. The other end of the linkage 42 extends out of a side of the movable member 47 facing away from the support 41, and serves as a contact connection end 421 connecting to the movable contact within the vacuum arc extinguishing chamber.

[0026] In one embodiment, a screw is used as the linkage 42, and a nut in threaded connection to the linkage 42 is used as the flange 422. The movable member 47 is adaptively provided with an inner thread mating with an outer thread of the screw, so that during assembly, the position of the movable member can be adjusted in the axial direction of the linkage 42. This adjustment is continuous, and the movable member is adjusted to a suitable position and then fixed relative to the linkage. In another embodiment, the linkage 42 is provided with a plurality of positioning portions in the axial direction, such as a plurality of circumferential grooves. These circumferential grooves communicate with each other by means of one or more grooves extending in the axial direction of the linkage, and an inner wall of the movable member 47 is formed with a matching positioning protrusion. By moving the positioning protrusion along the axial groove to a corresponding circumferential groove and into the circumferential groove, the position of the movable member in the axial direction of the linkage can be adjusted. In yet another embodiment, the linkage is provided with a plurality of positioning holes in the axial direction. The movable member is provided with a corresponding aperture. After the movable member is adjusted in the axial direction of a rod member to a suitable position, a positioning pin or nail is inserted into the aperture and an aligned positioning hole, so that positioning of the movable member relative to the linkage can also be realized. In yet another embodiment, the movable member may be tightly sleeved on the linkage. In other embodiments, the position of the movable member may also be configured to be unadjustable relative to the linkage. For example, the movable member is welded or bonded to the linkage.

[0027] An installation indication portion 471 and a wear indication portion 472 are provided at the outer circumference of the movable member 47. In the illustrated embodiment, each of the installation indication portion 471 and the wear indication portion 472 is configured to be an indication line extending in a circumferential direction of the movable member 47. The installation indication portion 471 is closer to the contact connection end 421 of the linkage 42 than the wear indication portion 472. In other embodiments, the installation indication portion 471 and the wear indication portion 472 may have other forms, such as an image marker, a text marker, a scale marker, a color marker, or a combination of at least two of the forms, etc. The use of a scale marker may facilitate indication of the degree of wear of the movable contact and the stationary contact in real time.

[0028] An insulation sleeve 44 is further sleeved on the linkage 42. In the illustrated embodiment, the insulation sleeve 44 may be a heat shrink tube sleeved on the linkage and passing through the support 41 and the contact spring 45. In other embodiments, the insulation sleeve may be sleeved on the linkage, and be provided with a radially extending flange at a position proximate to one end. The insulation sleeve passes through the support and the contact spring, and is placed on the support by means of the radially extending flange, such that the support supports the insulation sleeve. A first insulation pad 43 may further be arranged between a side of the support 41 facing away from the sleeve tube 46 and the flange 422 on the linkage 42. The first insulation pad 43 is sleeved on the linkage 42. In addition, a second insulation pad 48 may be arranged on a side surface of the movable member 47 facing the contact connection end 421 of the linkage 42. The second insulation pad 48 is sleeved on the linkage 42.

[0029] The principles of the contact support assembly 4 of the present utility model are described in detail below with reference to FIG. 4 and FIG. 5.

[0030] FIG. 4 shows that under initial normal assembly (the movable and stationary contacts within the vacuum arc extinguishing chamber are not worn), when the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed, the installation indication portion 471 of the movable member 47 is exposed outside of the sleeve tube 46, and an operator determines that the contact support assembly 4 is properly installed based on the visible or detectable installation indication portion 471. At the time, the wear indication portion 472 is not visible or detectable by the operator since the wear indication portion is located within the sleeve tube 46. The installation indication portion 471 specifies a reference position at which the contact support assembly 4 and the vacuum arc extinguishing chamber are properly assembled, and such arrangement means that the movement stroke of the contact spring is basically fixed. After the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed, the contact spring 45 is compressed under the operation of the linkage assembly 5, so as to ensure sufficient contact pressure and over travel of the movable contact and the stationary contact. In this case, the installation indication portion 47 is required to be exposed outside of the sleeve tube 46. For example, the installation indication portion can be just flush with or slightly above an upper edge of the sleeve tube 46, so as to provide an accurate installation indication to the operator.

[0031] As shown in FIG. 5, once the movable and stationary contacts are worn, when the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed based on the same operation of the linkage assembly 5, the installation indication portion 471 of the movable member 47 moves away from the upper edge of the sleeve tube 46 due to a larger stroke of the linkage 42, while the wear indication portion 472 is exposed outside of the sleeve tube 46. The operator identifies a position change of the wear indication portion (relative to the sleeve tube) based on the fact that the wear indication portion 472 is visible or detectable, thereby determining that the wear thickness of the movable and stationary contact has reached a predetermined value (for example, about 3 mm). For example, the wear indication portion 472 can be just flush with or slightly above the upper edge of the sleeve tube 46, so as to provide accurate wear indication to the operator.

[0032] In embodiments in which the movable member 47 can move relative to the linkage 42 to adjust the position thereof on the linkage, for example, when the linkage 42 is in threaded connection with the movable member 47, if the operator notices that the position of the wear indication portion 472 has exceeded the sleeve tube 46, the position of the movable member 47 can be adjusted in the axial direction of the linkage 42 to reset the contact support assembly 4 to the initial normal assembly state shown in FIG. 4. That is, when the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed, the installation indication portion 471 of the movable member 47 is exposed outside of the sleeve tube 46 and can be directly identified by the operator, while the wear indication portion 472 is located inside the sleeve tube 46 and cannot be directly identified by the operator. In this way, normal operation of the vacuum circuit breaker can be ensured by simply adjusting the movable member without having to frequently replace worn movable and stationary contacts, or adjust the complex opening / closing operating mechanism and the linkage assembly 5.

[0033] Although the illustrated embodiment shows that the linkage sequentially passes through the support, the contact spring and the movable member and is connected to the movable member, those skilled in the art could consider other variations. For example, the contact spring is disposed on the support, and a connecting portion (e.g., a connecting member provided with a recess or a bolt) is arranged at an end portion of the contact spring located away from the support. One end of the linkage is connected to the connecting portion (for example, inserted into the recess or fixed by the bolt), and the other end is connected to the movable contact, and then the movable member is sleeved on the linkage. In this way, when the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed, the contact spring can be compressed by operating the linkage assembly, such that a pushing force can be transferred to the movable contact by means of the linkage, thereby ensuring sufficient contact pressure and over travel of the movable contact and the stationary contact. At the same time, the movable member can provide an accurate installation indication or wear indication to the operator.

[0034] In addition, in other embodiments not shown, the wear indication portion of the movable member can be arranged to be closer to the contact connection end of the linkage than the installation indication portion. Under initial normal assembly, when the movable contact and the stationary contact within the vacuum arc extinguishing chamber are closed, the installation indication portion and the wear indication portion of the movable member can both be directly identified (visible or detectable) by the operator. If the movable contact and the stationary contact within the vacuum arc extinguishing chamber are worn, when the movable contact and the stationary contact are closed, due to the increased stroke of the linkage, the wear indication portion is concealed by the vacuum arc extinguishing chamber (for example, blocked by a lower edge of the vacuum arc extinguishing chamber) or blocked by other members. The operator can identify a position change of the wear indication portion according to the fact that the wear indication portion is not visible or detectable, so as to determine the degree of wear of the movable and stationary contacts.

[0035] It should be appreciated that although the description is presented according to each embodiment, each embodiment does not necessarily include only one independent technical solution. The presentation manner of the description is merely for clearness, and those skilled in the art should regard the description as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other implementations comprehensible by those skilled in the art.

[0036] What is described above is merely exemplary specific implementations of the present utility model, but is not intended to limit the scope of the present utility model. Any equivalent change, modification, or combination made by a person skilled in the art without departing from the conception and principle of the present utility model shall fall within the scope of protection of the present utility model.

Claims

1. A contact support assembly, characterized by comprising: a support (41); a contact spring (45), supported by the support (41); a movable member (47), connected to and moving along with the contact spring (45) and having a wear indication portion (472); and a linkage (42), connected to the movable member (47) and having a contact connection end (421), wherein relative positions of the movable member (47) and the linkage (42) are configured such that during closing of contacts, a position change of the wear indication portion (472) is identifiable when one of the contacts reaches a predetermined wear thickness value.

2. The contact support assembly according to claim 1, wherein the linkage (42) passes through the movable member (47), and the movable member (47) is adjustably installed on the linkage (42) in the axial direction thereof relative to the linkage (42).

3. The contact support assembly according to claim 1, wherein the linkage (42) passes through the support (41) and the contact spring (45) and is connected to the movable member (47), a flange (422) is formed at one end of the linkage (42) on a side of the support (41) facing away from the contact spring (45), and the other end of the linkage (42) extends out of the movable member (47) and serves as the contact connection end (421).

4. The contact support assembly according to claim 3, wherein an insulation sleeve (44) is sleeved on the linkage (42), and the insulation sleeve (44) passes through the contact spring (45) and the support (41).

5. The contact support assembly according to claim 3, wherein a first insulation pad (43) is sleeved on the linkage (42), and the first insulation pad (43) is located between the support (41) and the flange (422), and / or a second insulation pad (48) is sleeved on the linkage (42), and the second insulation pad (48) is arranged on a side surface of the movable member (47) facing away from the support (41).

6. The contact support assembly according to any one of claims 1 to 5, wherein the contact spring (45) is accommodated in a sleeve tube (46) supported by the support (41), and the wear indication portion (472) is configured such that during closing of the contacts, the wear indication portion (472) is capable of moving outside of the sleeve tube (46) to be identified when one of the contacts reaches the predetermined wear thickness value.

7. The contact support assembly according to any one of claims 1 to 5, wherein the movable member (47) is supported by the contact spring (45), and the wear indication portion (472) is an indication line formed on an outer circumferential surface of the movable member (47).

8. The contact support assembly according to any one of claims 1 to 5, wherein the movable member (47) further has an installation indication portion (471), and the installation indication portion (471) is located away from the support (41) relative to the wear indication portion (472).

9. A vacuum arc extinguishing assembly, comprising: a vacuum arc extinguishing chamber (3), provided with a movable contact and a stationary contact capable of moving relative to each other; and a contact support assembly (4), connected to the movable contact, the vacuum arc extinguishing assembly being characterized in that: the contact support assembly (4) is the contact support assembly according to any one of claims 1 to 8, wherein the contact connection end (421) of the linkage (42) is connected to the movable contact.

10. A vacuum circuit breaker, comprising: a housing; a vacuum arc extinguishing assembly, accommodated in the housing; and an operating mechanism, connected to the vacuum arc extinguishing assembly, the vacuum circuit breaker being characterized in that: the vacuum arc extinguishing assembly is the vacuum arc extinguishing assembly according to claim 9, wherein the operating mechanism is connected to the support (41) of the contact support assembly (4).

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