Contact opening and closing system of a rotary double-break circuit breaker

Abstract

The utility model discloses a kind of contact on-off systems of rotary double-break point circuit breaker, including center pivot, conducting contact bridge, contact spring, spring pin shaft, rolling bearing and pivot protective cover, center pivot includes two shaft pieces and two shaft columns, installation area is formed between two shaft pieces, two eccentric side wall parts are rotationally symmetrical and arranged on the side wall of shaft piece;Conducting contact bridge is rotatably installed in installation area;Each spring clamping groove is provided with contact spring, the free end of each contact spring is connected with a spring pin shaft, and rolling bearing is arranged on spring pin shaft;Pivot protective cover is fixedly connected with the two ends of center pivot.The contact on-off system of the utility model, through the shape constraint and connecting relationship between each component of system, ensure the conducting performance and reliability of circuit breaker, while effectively avoid the arc reignition hidden danger caused by the backfall of conducting contact bridge after electric repulsion repulsion and the ablation of each component caused by arc flying.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical switch technology, specifically relating to a contact switching system for a rotary double-break molded case circuit breaker. Background Technology

[0002] Molded case circuit breakers, as the core protection device of low-voltage power distribution systems, have become an important development direction for current low-voltage circuit breaker products due to their advantages such as simple structure, small size and excellent arc extinguishing performance. However, this type of circuit breaker still has certain technical shortcomings.

[0003] Currently, researchers both domestically and internationally have developed circuit breakers with features such as automatic locking to prevent rebound after the moving contact is pushed back and pressure self-balancing after wear of the moving and stationary contacts, addressing the problems existing in rotary double-break molded case circuit breakers. For example, utility model application No. 202320771503.3 discloses a switching mechanism for a double-layer rotary double-break circuit breaker, including a fixed plate and a conductive contact bridge installed in the fixed plate via a fixed shaft. The fixed plate consists of a plate and a column, and the conductive contact bridge is movably installed in the space formed by the plate and the column. A spring pin is installed in a pin groove on the plate, and springs are attached to both ends of the spring pin; two sets of spring pins are respectively placed at both ends of the conductive contact bridge. Although this device ensures the conductivity and reliability of the circuit breaker by adopting a double-layer fixed plate structure and a double-layer synchronous spring and spring pin cooperation mode, it also adds an anti-drop shoulder to the conductive contact bridge, effectively avoiding the hidden danger of arc reignition caused by the conductive contact bridge falling back. However, these improvement solutions often only address single defects and lack a systematic design, making it difficult to maximize the overall performance of the contact switching system and to protect and install components. Therefore, a better technical solution is urgently needed to solve these problems. Utility Model Content

[0004] This utility model aims to overcome the shortcomings of the prior art and provides a contact switching system for a rotary double-break circuit breaker. Through the form and position constraints and connection relationships between the components of the system, the conductivity and reliability of the circuit breaker are guaranteed. At the same time, it effectively avoids the risk of arc reignition caused by the fall of the conductive contact bridge after being repelled by electric repulsion force, as well as the burning of various components caused by flying arc.

[0005] To achieve the above objectives, this utility model provides a contact switching system for a rotary double-break circuit breaker, comprising a central rotating shaft, a conductive contact bridge, contact springs, spring pins, and rolling bearings. The central rotating shaft includes two symmetrically arranged shaft pieces, each with a shaft post on its opposite sides, forming an installation area between the two shaft pieces. Each shaft piece has two eccentric sidewall portions arranged symmetrically on its sidewall, each eccentric sidewall portion having a first positioning groove at one end and a second positioning groove at the other end. Two spring slots are also provided on the sidewalls of the two shaft pieces. The conductive contact bridge is rotatably installed within the installation area. Each spring slot contains a contact spring, and the free end of each contact spring is connected to a spring pin located in the second positioning groove. The spring pin is provided with a rolling bearing for rotatably contacting the two shaft pieces and the conductive contact bridge.

[0006] Furthermore, the eccentric sidewall portion is recessed inward from the circumference of the sidewall of the shaft piece; the first positioning groove is closer to the central axis of the central rotating shaft than the second positioning groove.

[0007] Furthermore, the spring slot is disposed on one side of the first positioning slot.

[0008] Furthermore, the sidewall of the conductive contact bridge is provided with a bearing rolling groove for rolling engagement with the rolling bearing.

[0009] Furthermore, the contact switching system also includes two rotating shaft protective covers, which are respectively fixedly connected to the central rotating shaft via positioning blocks on the shaft column.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] (1) The contact switching system of this utility model, by designing an eccentric arc on the side wall of the central rotating shaft and adding an anti-drop shoulder to the structure of the traditional conductive contact bridge, eliminates the previous anti-drop buckle of the conductive bridge, making the structure simpler and effectively preventing the hidden danger of arc reignition caused by the conductive contact bridge falling back. At the same time, a rolling bearing is installed on the spring pin, which successfully avoids excessive wear of the conductive contact bridge and the central rotating shaft during the operation of the system.

[0012] (2) In the contact switching system of this utility model, after the moving and stationary contacts wear out due to long-term operation, the conductive contact bridge can automatically balance the pressure of the two moving contacts through the action of spring torque, thus ensuring the conductivity and reliability of the circuit breaker.

[0013] (3) By adding a rotating shaft protective cover, this utility model avoids the burning of components caused by the flying arc during the arc extinguishing process of the contact switching system, thus ensuring the service life of each component of the circuit breaker.

[0014] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0016] Figure 1 This is a schematic diagram of the contact switching system of a rotary double-break circuit breaker according to this utility model;

[0017] Figure 2 This is a schematic diagram of the overall assembly structure of the contact switching system of this utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the central rotating shaft of this utility model;

[0019] Figure 4 This is a schematic diagram of a conductive contact bridge structure of a utility model;

[0020] Figure 5 This is a schematic diagram of the installation of the spring and spring shaft pin of the utility model.

[0021] Figure 6 This is a schematic diagram of the usage status of the contact switching system of the utility model. Figure 1 ;

[0022] Figure 7 This is a schematic diagram of the usage status of the contact switching system of the utility model. Figure 2 ;

[0023] Figure 8 This is a schematic diagram of the usage status of the contact switching system of the utility model. Figure 3 ;

[0024] Among them, 1-central rotating shaft; 1.1-shaft plate; 1.2-shaft column; 101-eccentric side wall; 102-first positioning groove; 103-second positioning groove; 104-spring slot; 105-positioning block; 106-spring groove; 2-conductive contact bridge; 201-moving contact; 202-anti-fall shoulder; 203-bearing rolling groove; 3-contact spring; 4-spring pin; 5-rolling bearing; 6-rotating shaft protective cover. Detailed Implementation

[0025] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0026] Please see Figures 1 to 8 This embodiment provides a contact switching system for a rotary double-break circuit breaker, including a central rotating shaft 1, a conductive contact bridge 2, a contact spring 3, a spring pin 4, and a rolling bearing 5. The specific structure is as follows:

[0027] The central rotating shaft 1 includes two integrally formed shaft pieces 1.1 and two shaft posts 1.2. The two shaft pieces 1.1 are arranged in parallel and symmetrically, and the two shaft posts 1.2 are located on opposite sides of the two shaft pieces 1.1. The two shaft pieces 1.1 and the two shaft posts 1.2 together form a mounting area 1b with openings on opposite sides. Each shaft piece 1.1 has two eccentric sidewall portions 101 with eccentric arc structures arranged rotationally and symmetrically on its sidewall. The eccentric sidewall portions 101 are recessed inward from the sidewall of the shaft piece 1.1. One end of the eccentric sidewall portion 101 is provided with a first positioning groove 102, and the other end of the eccentric sidewall portion 101 is provided with a second positioning groove 103; and the first positioning groove 102 is closer to the central axis of the central rotating shaft 1 than the second positioning groove 103. Meanwhile, two spring slots 104 are also provided on the side walls of the two shaft pieces 1.1. The two spring slots are located on both sides of the central shaft 1, and the two spring slots 104 are respectively set close to the two first positioning grooves 102, that is, one spring slot is provided on one side of each first positioning groove 102. Both ends of the central rotating shaft 1 are provided with grooves formed by shaft posts 1.2, and each groove is provided with a spring groove 106 on the two opposite inner side walls of the two shaft posts 1.2.

[0028] The conductive contact bridge 2 is coaxially and rotatably installed in the installation area 1b with the central rotating shaft 1. The side wall of the conductive contact bridge 2 is provided with a bearing rolling groove 203 for rolling cooperation with the rolling bearing 5.

[0029] Each spring slot 104 contains a contact spring 3, and the free end of each contact spring 3 is connected to a spring pin 4 located in the second positioning slot 103. The spring pin 4 is equipped with a rolling bearing 5 for rotating contact with the two shaft pieces 1.1 and the conductive contact bridge 2. The spring pin 4 is initially installed in the second positioning slot 103 under the tension of the contact spring 3. The contact switching system also includes two rotating shaft protective covers 6. The two rotating shaft protective covers 6 are fixedly connected to both ends of the central rotating shaft 1 through positioning blocks 105 on the shaft column 1.2, thereby protecting the contact switching system and effectively preventing the conductive contact bridge 2 from falling back after being repelled by electric repulsion, which could cause the arc to reignite and prevent the arc from burning various components.

[0030] When the circuit is in normal condition, as shown in the figure, the conductive contact bridge 2 is pulled by the contact spring 3, which makes the moving contact 201 at both ends of the conductive contact bridge 2 in close contact with the stationary contact embedded in the stationary contact plate, ensuring normal current conduction.

[0031] When a fault current occurs in the circuit, such as Figure 6 As shown, a large electric repulsive force is generated between the moving contact 201 and the stationary contact, which overcomes the force of the contact spring 3 and forces the conductive contact bridge 2 to push the spring pin 4 to rotate rapidly clockwise from the second positioning groove 103 along the eccentric side wall 101 of the central rotating shaft 1 to the maximum tension position of the contact spring 3.

[0032] When the contact spring passes its maximum tension position, such as Figure 7 As shown, at this time, the contact spring 3 will generate a contracting force along its own direction, pulling the spring pin 4 to move at the other end of the eccentric sidewall of the rotating shaft plate, continuing to drive the conductive contact bridge 2 to accelerate rotation until the spring pin 4 moves onto the anti-drop shoulder 202 of the conductive contact bridge, where it stops and achieves temporary locking. At this time, the spring pin 4 enters the first positioning groove 102; simultaneously, the release device of the external operating mechanism spontaneously completes the release, achieving complete self-locking of the conductive contact bridge 2 through the central rotating shaft 1, as shown. Figure 8 As shown.

[0033] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A contact switching system for a rotary double-break circuit breaker, characterized in that, The device includes a central rotating shaft (1), a conductive contact bridge (2), a contact spring (3), a spring pin (4), and a rolling bearing (5). The central rotating shaft (1) includes two symmetrically arranged shaft pieces (1.1). A shaft post (1.2) is provided on each opposite side of the two shaft pieces (1.1). An installation area is formed between the two shaft pieces (1.1). Two eccentric sidewall portions (101) are rotationally symmetrically arranged on the sidewall of each shaft piece (1.1). One end of each eccentric sidewall portion (101) is provided with a first positioning groove (102). 101) A second positioning groove (103) is provided at the other end; two spring slots (104) are also provided on the side walls of the two shaft pieces (1.1); the conductive contact bridge (2) is rotatably installed in the installation area; a contact spring (3) is provided in each spring slot (104), and the free end of each contact spring (3) is connected to a spring pin (4) located in the second positioning groove (103), and a rolling bearing (5) is provided on the spring pin (4) for rotating contact with the two shaft pieces (1.1) and the conductive contact bridge (2).

2. The contact switching system according to claim 1, characterized in that, The eccentric sidewall portion (101) is recessed inward from the circumference of the sidewall of the shaft piece (1.1); the first positioning groove (102) is closer to the central axis of the central rotating shaft (1) than the second positioning groove (103).

3. The contact switching system according to claim 2, characterized in that, The spring slot (104) is located on one side of the first positioning slot (102).

4. The contact switching system according to claim 1, characterized in that, The conductive contact bridge (2) has a bearing rolling groove (203) on its side wall for rolling engagement with the rolling bearing (5).

5. The contact switching system according to claim 1, characterized in that, The contact switching system also includes two rotating shaft protective covers (6), which are fixedly connected to the central rotating shaft (1) via positioning blocks (105) on the shaft column (1.2).

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