WO2015071734A1

WO2015071734A1 - Insulation sleeve for embedded pole and method of manufacturing the same

Info

Publication number: WO2015071734A1
Application number: PCT/IB2014/002420
Authority: WO
Inventors: Qingqi Chen; Lihua Bao
Original assignee: Eaton Corporation
Priority date: 2013-11-15
Filing date: 2014-11-12
Publication date: 2015-05-21
Also published as: CN104658812B; CN104658812A

Abstract

In the present invention an insulation sleeve (100) for an embedded pole (200) is provided. The embedded pole (200) comprises a first terminal (202) and a second terminal (203) arranged circumferentially at a distance from each other. The insulation sleeve (100) comprises: a sleeve body (1) into which the embedded pole (200) is configured to be inserted, the sleeve body (1) being made of insulating material,. and a first fixed contactor (2) and a second fixed contactor (3) both arranged on an inner circumferential surface of the sleeve body (1) and spaced from each other, wherein the first fixed contactor (2) is configured to electrically connect with the first terminal (202) and the second fixed contactor (3) is configured to electrically connect with the second terminal (203). In the present invention a circuit breaker assembly including the embedded pole (200) and the insulation sleeve (100), a switchgear cabinet, and a method of manufacturing the insulation sleeve are also provided.

Description

Insulation Sleeve for Embedded Pole and

Method of Manufacturing the Same

Technical Field

The present invention relates to the field of electrical apparatus, and in particular an insulation sleeve for embedded poles and method of manufacturing the same. Further, the present invention also relates to a circuit breaker assembly having an embedded pole and an insulation sleeve, and to a switchgear cabinet.

Background

Nowadays, switchgear cabinets have been widely used in the field of power transmission and transformation. In a switchgear cabinet, there is typically provided a set of fixed contactors for engaging with and disengaging from corresponding moveable contactors. It has been proposed that an embedded pole is comprised of two co-operating moveable contactors and forms a vacuum interrupter, i.e. a circuit breaking arrangement, for the purpose of eliminating any adverse effect caused by short circuit currents. Chinese Utility Model No. CN202758804U assigned to the same assignee discloses an axially extending embedded pole which at its outer surface is enclosed by an insulating layer, and has an upper outlet terminal and a lower outlet terminal that extend from a lateral side substantially perpendicularly to the longitudinal axis of the embedded pole and are to be inserted into a corresponding fixed contactor seat, respectively.

It is still desirable to reduce the dimensions of such embedded pole, without compromising its insulation performance. Chinese Utility Model No. CN201503809U discloses a step-shaped insulation sleeve for a 24 KV high-voltage vacuum embedded pole breaker, with the middle of the sleeve being slimmer than its both ends. The insulation sleeve completely shields ports of outlet arms of the embedded pole. The insulation sleeve improves the insulation performance, and meanwhile reduces the insulating distance by means of its sleeve body which is inherently insulating. However, the received embedded pole is still required to be connected to the fixed contactors via the laterally extending outlet terminals. In particular, during the engagement and disengagement of the outlet terminals with the two fixed contactor seats, a breakdown is still possible between the upper and lower outlet terminals as they now extend out of the insulation sleeve. Furthermore, there is no reduction in the radial dimension of the embedded pole that is used with such insulation sleeve.

Summary of Invention

Therefore, an object of the present invention is to provide a novel insulation sleeve for embedded pole, substantially reducing the dimension, especially the radial dimension, of the embedded pole used therewith sleeve, and still having an excellent insulation performance.

In the present invention, therefore, an insulation sleeve for an embedded pole that has a first terminal and a second terminal arranged circumferentially at a distance from each other is provided, comprising a sleeve body into which the embedded pole is configured to be inserted. The sleeve body is made of insulating material.

It is apparent from the above that the insulation sleeve according to the present invention not only has an insulation function, but also forms electrical connection with the embedded pole by means of two fixed contactors provided on the inner circumferential surface of the sleeve body of the insulation sleeve, resulting in simplified operation and structure thereof. Due to the two fixed contactors being cast in one single insulation sleeve, the mechanical engagement and disengagement of the insulation sleeve according to the invention with the embedded pole can be realized by simply displacing the embedded pole along the sleeve body. The fixed contactors and thus the terminals of the embedded pole may have a higher coaxiality with each other and form a more reliable electrical connection, as compared to the laterally extending terminals of the prior art embedded pole. Moreover, the two fixed contactors may be set to have a proper distance therebetween and to be provided with a suitable shielding and insulating feature, such as corrugations, in order to efficiently eliminate electrical arcing. In addition, due to the two fixed contactors, in particular a first fixed contactor, enclosed by the insulation sleeve, an electric shock accident can be avoided, improving safety and reliability.

Preferably, the insulation sleeve further comprises a first fixed contactor and a second fixed contactor that are arranged on an inner circumferential surface of the sleeve body and spaced from each other, wherein the first fixed contactor is configured to electrically connect with the first terminal and the second fixed contactor is configured to electrically connect with the second terminal. The first fixed contactor is arranged at a longitudinal end of the sleeve body and the second fixed contactor is arranged longitudinally at a middle point of the sleeve body.

In a particularly preferred embodiment, the insulation sleeve can also comprise a cable cone integrally formed with or fixedly connected to the sleeve body at a longitudinal end, wherein the cable cone has an outer conical surface and a bore for receiving a first conductor. The arrangement of such cable cone enables simply and efficiently standardized installation and operation. Preferably, the cable cone on its outer conical surface forms a circumferential annular groove and the insulation sleeve includes a metallic support ring received in the annular groove.

As an interpretation but not limitation, the preferred metallic support ring according to the present invention has an advantage that the insulation sleeve can be mounted in such a manner that one end thereof is fixedly fastened and the other end is mounted in form of a movable hinge, i.e. the metallic support ring, as a portion of the moveable contactor, can be supported, but not fastened in the switchgear cabinet, which not only eliminates and reduces the over-constraints of fastening, but more importantly eliminates or reduces the electrical discharge from the first fixed contactor or the end where the cable cone is located due to the stress points produced by e.g. threaded fastening.

In another embodiment, the insulation sleeve can also include a receptacle for receiving a second conductor, wherein the receptacle is integrally formed with or fixedly connected to the sleeve body on an outer circumferential surface of the sleeve body at a position where the second fixed contactor is located.

Preferably, the first and/or second fixed contactors are in the form of an electrically conductive metallic rings. By means of such arrangement, the fixed contactors have a very high coaxiality, such that the terminals of the embedded pole can also be configured correspondingly as two coaxially metallic collars. In another aspect of the invention, a circuit breaker assembly is provided, comprising the insulation sleeve according to the invention and an embedded pole configured to be inserted into the sleeve body of the insulation sleeve, wherein the embedded pole has a cylindrical body, a ring-shaped first terminal and a ring-shaped second terminal, the first and second terminals being arranged on an outer circumferential surface of the cylindrical body and spaced from each other. In yet another aspect of the invention, a switchgear cabinet is provided, comprising an insulation sleeve, an embedded pole, a first wall for fastening the insulation sleeve and a second wall for supporting a metallic support ring. The insulation sleeve has a sleeve body made of insulating material , and a first fixed contactor and a second fixed contactor both arranged on an inner circumferential surface of the sleeve body and spaced from each other, wherein the first fixed contactor is arranged at a longitudinal end of the sleeve body. The insulation sleeve further comprises a cable cone integrally formed with or fixedly connected to the sleeve body at the longitudinal end, wherein the cable cone has an outer conical surface and a circumferential annular groove formed on the outer conical surface. The insulation sleeve further comprises the metallic support ring received in the annular groove. The embedded pole has a cylindrical body, and a ring-shaped first terminal and a ring-shaped second terminal, wherein the first and second terminals are arranged on an outer circumferential surface of the cylindrical body and spaced from each other. In the switchgear cabinet according to the present invention, the second wall has an opening through which the cable cone is configured to pass and a collar member supported along the circumference of the opening, and the collar member contacts with and movably supports the metallic support ring. It can be appreciated that the cable cone of the insulation sleeve can be supported in an opening of the first wall. Therefore, the insulation sleeve can be securely fixed by only fastening the end of the insulation sleeve opposed to the cable cone. This fixation is simple, convenient and reliable, and as described above, this reduces or eliminates electrical discharge caused by stress points. In another aspect according to the present invention, a method of manufacturing an over-casting or sealing-in type of insulation sleeve is provided, comprising steps of: providing a first fixed contactor; casting a cable cone section, with the first fixed contactor being fixedly embedded in the cable cone section by the casting; providing a second fixed contactor; casting a sleeve body section, with the second fixed contactor being fixedly embedded in the sleeve body section by the casting; and fixing the cable cone section around a longitudinal end of the sleeve body section.

In another aspect according to the present invention, a method of manufacturing an integrally casting or sealing-in type of insulation sleeve is further provided, comprising steps of: providing a first fixed contactor; integrally casting a sleeve body and a cable cone at a longitudinal end of the sleeve body, with the first fixed contactor being fixedly embedded at the longitudinal end in the sleeve body by casting, wherein the sleeve body at its inner side has, in series, a first inner diameter portion adjacent to the longitudinal end, a second inner diameter portion having a greater inner diameter than that of the first inner diameter portion, and a third inner diameter portion having a greater inner diameter than that of the second inner diameter portion smaller than that of the second inner diameter portion; and fastening a second fixed contactor to the second inner diameter portion. Due to the subsequently decrease of the inner diameters of the first, second and third inner diameter portions, the mold core used for casting can be conveniently drawn out of the interior of the formed insulation sleeve once the casting is completed.

Additional features and advantages of the present invention will be partially discussed in the following description and the others will be apparent to the skilled in the art after reading this disclosure.

Brief Description of Drawings

The present invention will be discussed in the following detailed description with reference to the accompanying drawings, in which:

Figure 1 shows a cross-sectional view of an insulation sleeve for embedded pole according to the invention;

Figure 2 shows a partial sectional view of a switchgear cabinet equipped with a circuit breaker assembly comprising the insulation sleeve shown in Fig. 1 and an embedded pole;

Figure _3a shows a cross-sectional view of an over-casting or sealing-in type of insulation sleeve before assembly, with the sleeve body section 1 ' and cable cone section 4' being in separated condition; Figure 3b shows a cross-sectional view of the insulation sleeve shown in Fig.

3a after assembly, with the sleeve body section 1 ' and cable cone section 4' being in engaged condition;

Figure 4 shows a cross-sectional view of an integrally casting or sealing-in type of insulation sleeve. Throughout the drawings and the description, same or similar reference numerals indicate the same or similar features or elements.

Detailed Description

The embodiments of the device in this disclosure are hereby described in accordance with the detailed description, with reference to the accompanying drawings. Although the accompanying drawings are provided for the purpose of illustrating the exemplary embodiments of the present invention, they need not to be drawn in scale, but rather some features might be exaggerated, removed or sectioned for better illustrations of the present invention. Referring to Fig.1 , an insulation sleeve 100 comprises a sleeve body 1 , a first fixed contactor 2, a second fixed contactor 3 and a cable cone 4. The sleeve body 1 has a cylindrical shape, and is made of an insulating material, such as epoxy resins. The sleeve body 1 has inner corrugations distributed circumferentially along an inner circumferential surface thereof. The first fixed contactor 2 and the second fixed contactor 3 are both arranged on the inner circumferential surface of the sleeve body 1 and spaced from each other, with the first fixed contactor 2 being arranged at one longitudinal end of the sleeve body 1 and the second fixed contactor 3 being disposed longitudinally at the middle point of the sleeve body 1. The first fixed contactor 2 and the second fixed contactor 3 both can be in form of an electrically conductive metallic ring. However, it will be appreciated that the first and second fixed contactors can have other suitable shapes, e.g., in a continuous or discontinuous form. The cable cone 4 may be a universal cable cone, preferably a standard cable cone, which has an outer conical surface 40 and a bore 41. The cable cone 4 is integrally formed with the sleeve body 1 at the longitudinal end of the insulation sleeve 100 where the first fixed contactor is located. The sleeve body is opened at other end opposed to the end where the fixed contactor is located, for the purpose of insertion of an embedded pole 200 (Fig. 2). By means of a bolt, the first fixed contactor 2 engages with a first conductor 7 received in the bore 41 (Fig. 2). The cable cone 4 forms a circumferential annular groove 45 on the outer conical surface 40 thereof and a metallic support ring is received in the annular groove 45. Further, the insulation sleeve 100 at its middle portion has a receptacle 6 for receiving a second conductor 8, which receptacle 6 is integrally formed with the sleeve body 1 on its outer circumferential surface at the position where the second fixed contactor 3 is located, such that the second conductor 8 received in the receptacle 6 can be fastened to, by e.g. a screw, and thus can electrically connect with the second fixed contactor 3. Although in the illustrated embodiment the receptacle 6 is integrally formed with the sleeve body, it can be fixedly fastened to the sleeve body 1. Referring to Fig. 2, a switchgear cabinet 300 accommodates a plurality of the insulation sleeves 100 arranged parallel to each other in the transverse direction, with the respective embedded poles 200 being configured to be inserted into the sleeve body 1 of the insulation sleeves 100. The embedded poles 200 each are in form of a cylindrical shape and have a cylindrical body 201 , a ring-shaped first terminal 202 and a ring-shaped second terminal 203 both arranged on the outer circumferential surface of the cylindrical body 201 and spaced from each other, with the first fixed contactor 2 of the insulation sleeves 100 being configured to electrically connect with the first terminal 202 of the embedded poles 200, while the second fixed contactor 3 being configured to electrically connect with the second terminal 203.

Still referring to Fig. 2, the switchgear cabinet 300 comprises a first wall 301 having a first opening 301 1 , and a second wall 302. The insulation sleeve 100 can be fastened within the first opening 301 1 , or be fastened to the first wall 301 around the first opening 301 1. The second wall 302 has a second opening 3021 and a collar member 3022 supported along a circumferential direction of the second opening 3021. The cable cone 4 passes through the second opening 3021 . The metallic support ring 5 disposed in the annular groove 45 of the cable cone contacts with the collar member 3022, and thus is moveably supported by the collar member 3022, such that a uniform contact is formed between the metallic support ring 5 and the collar member 3022, reducing or eliminating an electrical discharge.

Still referring to Fig. 2, a first connection cable 9 is inserted onto the cable cone 4, and thus electrically connects with the first contactor 2 via the first conductor 7 and a second connection cable 10 electrically connects with the second fixed contactor 3 via the second conductor 8. Preferably, in a three-phase alternating current switchgear cabinet three circuit breaker assemblies may be provided accordingly, each comprising an insulation sleeve 100 and an embedded pole 200. The configuration according to the present invention may be applied to at least one, or preferably all, of the assemblies. By means of this connection described, an electrical current is capable of flowing from the first connection cable 9, through the embedded pole 200, to the second connection cable 10, with a short circuit current or a normal load current being realized by the manipulation of the embedded poles 200. Notwithstanding, the mechanical engagement or disengagement between the embedded poles 200 and the fixed contactors of the insulation sleeves can be realized by inserting or withdrawing the embedded poles. When the embedded pole 200 is being withdrawn, the first and second fixed contactors 2, 3 are separated away from the first and second terminals 202, 203, respectively. It will be understood that the first and second fixed contactors 2, 3 of the insulation sleeves 100 can be spaced from a distance greater than a safe distance, for the purpose of preventing from a high-voltage arcing occurred therebetween, and thus eliminating a dangerous situation.

Referring back to Fig. 1 , the method of manufacturing the insulation sleeve 100 according to the embodiments may be realized by providing first and second fixed contactors 2, 3 both in form of an electrically conductive metallic ring, and then integrally forming a sleeve body 1 of the insulation sleeve with a cable cone 4 by casting an insulating material, such as epoxy resins. In this way, the manufacture is particularly simple.

Referring to Figs. 3a and 3b, another embodiment of an insulation sleeve 100 according to the present invention is illustrated and the method of manufacturing the insulation sleeve 100 comprises: providing a first fixed contactor 2; casting a cable cone section 4', with the first fixed contactor 2 being fixedly embedded in the cable cone section 4' by the casting; providing a second fixed contactor 3; casting a sleeve body section V, with the second fixed contactor 3 being fixedly embedded in the sleeve body section V by the casting; and fixing the cable cone section 4' around a longitudinal end of the sleeve body section Γ.

Referring to Fig. 4, yet another embodiment of an insulation sleeve 100 according to the present invention is illustrated and the method of manufacturing the insulation sleeve 100 comprises: providing a first fixed contactor 2; integrally casting a sleeve body 1 and a cable cone 4 located at a longitudinal end of the sleeve body 1 , with the first fixed contactor 2 being fixedly embedded in the sleeve body 1 at the longitudinal end by the casting, wherein the sleeve body 1 at its inner side has, in series, a first inner diameter portion 1 1 adjacent to the longitudinal end, a second inner diameter portion 12 having a greater inner diameter than that of the first inner diameter portion 1 1 , and a third inner diameter portion 13 having a greater inner diameter than that of the second inner diameter portion 12; and fastening a second fixed contactor 3 to the second inner diameter portion 12, e.g., by a screw.

Although the sleeve body 1 is in form of a cylindrical shape in the illustrated embodiments, it will be conceivable by the person skilled in the art that the sleeve body may has other cross-sectional shapes, such as rectangle, polygon, ellipse or other suitable shapes and the fixed contactors may also have corresponding cross-sectional profiles.

It should be appreciated that the foregoing descriptions are illustrative, and should not be construed as limitation. In addition to the embodiments illustrated, it should be conceivable for the person skilled in the art, after reading the description, that any obvious modification, variation and alternative on the basis of the teachings of the present invention falls within the scope of the present invention.

Claims

We claim:

1. An insulation sleeve (100) for an embedded pole (200), wherein the embedded pole (200) comprises a first terminal (202) and a second terminal (203) arranged circumferentially at a distance from each other, the insulation sleeve (100) comprising: a sleeve body (1) into which the embedded pole (200) is configured to be inserted, the sleeve body (1 ) being made of insulating material; and a first fixed contactor (2) and a second fixed contactor (3) both arranged on an inner circumferential surface of the sleeve body (1 ) and spaced from each other, wherein the first fixed contactor (2) is configured to electrically connect with the first terminal (202) and the second fixed contactor (3) is configured to electrically connect with the second terminal (203).

2. The insulation sleeve (100) according to claim 1 , characterized in that the first fixed contactor (2) is arranged at a longitudinal end of the sleeve body (1 ) and the second fixed contactor (3) is arranged longitudinally at a middle point of the sleeve body (1 ).

3. The insulation sleeve (100) according to claim 2, characterized in that the insulation sleeve further comprise a cable cone (4) integrally formed with or fixedly connected to the sleeve body at the longitudinal end, wherein the cable cone (4) has an outer conical surface (40) and a bore (41 ) for receiving a first conductor (7).

4. The insulation sleeve (100) according to claim 3, characterized in that the cable cone (4) on its outer conical surface (40) forms a circumferential annular groove (45) and the insulation sleeve (100) has a metallic support ring (5) received in the annular groove (5).

5. The insulation sleeve (100) according to claim 1 , characterized in that the insulation sleeve (100) further has a receptacle (6) for receiving a second conductor (8), wherein the receptacle (6) is integrally formed with or fixedly connected to the sleeve body (1 ) on an outer circumferential surface of the sleeve body (1 ) at a position where the second fixed contactor is located (3).

6. The insulation sleeve (100) according to claim 1 , characterized in that the first and/or second fixed contactors (2, 3) are in the form of an electrically conductive metallic ring.

7. A circuit breaker assembly, comprising the insulation sleeve (100) according to any of claims 1 to 6, and an embedded pole (200) configured to be inserted into the sleeve body (1 ) of the insulation sleeve (100), wherein the embedded pole (200) has a cylindrical body (201), a ring-shaped first terminal (202) and a ring-shaped second terminal (203), the first and second terminals (202, 203) being arranged on an outer circumferential surface of the cylindrical body (201 ) and spaced from each other.

8. A switchgear cabinet, comprising: an insulation sleeve (100) having a sleeve body (1) made of insulating material, a first fixed contactor (2) and a second fixed contactor (3) both arranged on an inner circumferential surface of the sleeve body (1 ) and spaced from each other, the first fixed contactor (2) being arranged at a longitudinal end of the sleeve body (1 ), a cable cone (4) integrally formed with or fixedly connected to the sleeve body (1 ) at the longitudinal end, the cable cone (4) having an outer conical surface (40) and a circumferential annular groove (45) formed on the outer conical surface (40), and a metallic support ring (5) received in the annular groove (45); an embedded pole (200) having a cylindrical body (201), a ring-shaped first terminal (202) and a ring-shaped second terminal (203), wherein the first and second terminals (202, 203) are arranged on an outer circumferential surface of the cylindrical body (201) and spaced from each other; a first wall (301) for fastening the insulation sleeve (100); and a second wall (302) for supporting the metallic support ring (5).

9. The switchgear cabinet according to claim 8, characterized in that the second wall (302) has an opening (3021 ) through which the cable cone (4) is configured to pass, and a collar member (3022) supported along the circumference of the opening (3021), wherein the collar member (3022) contacts with, and movably supports the metallic support ring (5).

10. A method of manufacturing an insulation sleeve, comprising: providing a first fixed contactor (2); casting a cable cone section (4'), with the first fixed contactor (2) being embedded in the cable cone section (4') by the casting; providing a second fixed contactor (3); casting a sleeve body section (1 '), with the second fixed contactor (3) being embedded in the sleeve body section (1') by the casting; and fixing the cable cone section (4') around a longitudinal end of the sleeve body section (V).

1 1. A method of manufacturing an insulation sleeve, comprising: providing a first fixed contactor (2); integrally casting a sleeve body (1 ) and a cable cone (4) at a longitudinal end of the sleeve body, with the first fixed contactor (2) being embedded in the sleeve body at the longitudinal end by the casting, wherein the sleeve body at its inner side has, in series, a first inner diameter portion (1 1) adjacent to the longitudinal end, a second inner diameter portion (12) having a greater inner diameter than that of the first inner diameter portion (1 1 ), and a third inner diameter portion (13) having a greater inner diameter than that of the second inner diameter portion (12); and fastening a second fixed contactor (3) to the second inner diameter portion (12).