Vacuum circuit breaker permanent magnet operating mechanism

Abstract

A permanent magnet operating mechanism for a vacuum circuit breaker includes a base plate. A ring-shaped magnetic yoke and a stationary iron core are fixed below the base plate, with the stationary iron core coaxially disposed within the inner cavity of the ring-shaped magnetic yoke. The stationary iron core has a ring-shaped structure with a closed upper end and an open lower end, and a through hole in the center of its upper end. A tripping coil and a permanent magnet are disposed between the stationary iron core and the ring-shaped magnetic yoke, with the tripping coil positioned above the permanent magnet. A coil frame is disposed within the inner cavity of the stationary iron core, and a closing coil is wound on the coil frame. A moving iron core is disposed below the stationary iron core and the ring-shaped magnetic yoke. The moving iron core has an inverted T-shaped structure, and its vertical end has a cylindrical structure inserted into a through hole in the center of the coil frame. A tripping spring is installed in the cylindrical structure. The lower end of a drive shaft passes through the tripping spring and is fixedly connected to the moving iron core. The upper end of the drive shaft passes through the through hole and the base plate and is connected to the insulating pull rod of the vacuum circuit breaker, causing the two ends of the tripping spring to abut against the moving iron core and the base plate, respectively. This invention overcomes the shortcomings of the prior art.

Description

Technical Field

[0001] This utility model belongs to the field of circuit breaker technology, and in particular relates to a permanent magnet operating mechanism for a vacuum circuit breaker. Background Technology

[0002] Existing permanent magnet operating mechanisms often use a shared electromagnetic and permanent magnet circuit. During closing and opening, the excitation current must overcome the magnetic reluctance of the permanent magnet, the coil, and the air gap to close the circuit, resulting in prolonged closing and opening times and increased current. Furthermore, the axial stacking of the closing and opening coils and permanent magnets in existing permanent magnet operating mechanisms makes it difficult to reduce the height of the operating mechanism, leading to a larger circuit breaker size that cannot meet the needs of applications with limited installation space. Additionally, the repulsion mechanism added to existing permanent magnet operating mechanisms is not integrated into the operating mechanism itself, but is instead located above or below it, further increasing the overall height of the operating mechanism. Utility Model Content

[0003] This invention provides a permanent magnet operating mechanism for a vacuum circuit breaker to overcome the shortcomings of the prior art.

[0004] The technical solution adopted by this utility model is as follows: a permanent magnet operating mechanism for a vacuum circuit breaker, comprising a base plate, an annular magnetic yoke and a stationary iron core fixed below the base plate, and the stationary iron core being coaxially arranged in the inner cavity of the annular magnetic yoke; the stationary iron core has an annular structure with a closed upper end and an open lower end, and has a through hole in the center of its upper end; a tripping coil and a permanent magnet are provided between the stationary iron core and the annular magnetic yoke, and the tripping coil is located above the permanent magnet; a coil frame is provided in the inner cavity of the stationary iron core, and a closing coil is wound on the coil frame;

[0005] Below the stationary iron core and the annular magnetic yoke is a moving iron core. The moving iron core has an inverted T-shaped structure, and its vertical end has a cylindrical structure and is inserted into the through hole in the center of the coil frame. The cylindrical structure contains a tripping spring. The lower end of the drive shaft passes through the tripping spring and is fixedly connected to the moving iron core. The upper end of the drive shaft passes through the through hole and the base plate and is connected to the insulating pull rod of the vacuum circuit breaker, so that the two ends of the tripping spring are respectively pressed against the moving iron core and the base plate.

[0006] When closing, the magnetic field generated by the energized closing coil forms a closing magnetic circuit on the stationary iron core and the moving iron core, causing the moving iron core to overcome the resistance of the opening spring and attract the stationary iron core, driving the drive shaft to move upward to complete the closing. After closing is completed and de-energized, the magnetic field generated by the permanent magnet forms a double holding magnetic circuit with the stationary iron core, the moving iron core, and the annular magnetic yoke to maintain the closing state. When opening, the magnetic field generated by the reverse energization of the opening coil weakens the magnetic force of the permanent magnet, making it less than the closing holding force of the circuit breaker. Under the combined action of the contact spring and the opening spring, the moving iron core drives the drive shaft to move downward to complete the opening.

[0007] The lower end face of the coil frame has an annular groove, and a repulsive coil is wound in the annular groove; a repulsive disk is provided on the moving iron core at a position relative to the repulsive coil.

[0008] The moving iron core is provided with an annular groove at a position relative to the repulsion coil, and the repulsion disk is annular and fixed in the annular groove.

[0009] The open end of the stationary iron core is provided with an annular shoulder, the permanent magnet is annular and is fitted around the stationary iron core, and its lower end sits on the annular shoulder.

[0010] The moving iron core is provided with an annular groove at a position relative to the permanent magnet.

[0011] The substrate is made of a non-magnetic material.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. In this invention, the permanent magnet does not participate in the closing circuit during the closing process. The excitation current of the closing coil does not need to overcome the magnetic resistance of the permanent magnet during the closing process. Therefore, the closing time is shortened and the closing current does not increase. Furthermore, after closing, the permanent magnet forms a dual magnetic circuit for holding, which increases the holding force for the same size.

[0014] 2. The tripping circuit of this utility model is independent of the closing circuit. When tripping, the tripping coil only needs to weaken the magnetic force of the permanent magnet, and only a very small current is needed to achieve rapid tripping. If it works in conjunction with the repulsion coil, tripping can be achieved in 1-3ms.

[0015] 3. The static iron core, closing coil, moving iron core, magnetic yoke, opening coil and permanent magnet of this utility model are radially assembled together, with a compact structure. In addition, the repulsion coil is integrated into the closing coil and the repulsion disk is integrated into the moving iron core. The repulsion mechanism does not increase the height of the product, so the height of the permanent magnet operating mechanism is reduced to 70-80mm, thereby reducing the size of the circuit breaker and meeting the needs of scenarios with limited installation space. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the open circuit structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the present invention in the closed state;

[0018] Figure 3 This is a cross-sectional schematic diagram of the static iron core structure of this utility model;

[0019] Figure 4 This is a cross-sectional schematic diagram of the moving iron core structure of this utility model;

[0020] Figure 5This is a cross-sectional schematic diagram of the coil frame structure of this utility model. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1-5 The present invention will be described in detail with reference to specific embodiments.

[0022] A permanent magnet operating mechanism for a vacuum circuit breaker includes a base plate 6 made of non-magnetic material. An annular magnetic yoke 1 and a stationary iron core 3 are fixed below the base plate 6, with the stationary iron core 3 coaxially disposed within the inner cavity of the annular magnetic yoke 1. The stationary iron core 3 has an annular structure with a closed upper end and an open lower end, and a through hole 3-1 at the center of its upper end. A tripping coil 7 and a permanent magnet 2 are disposed between the stationary iron core 3 and the annular magnetic yoke 1, with the tripping coil 7 located above the permanent magnet 2. A coil frame 8 is disposed within the inner cavity of the stationary iron core 3, and a closing coil 9 is wound on the coil frame 8.

[0023] Below the stationary iron core 3 and the annular magnetic yoke 1, a moving iron core 4 is provided. That is, the outer periphery of the moving iron core 4 must extend beyond the permanent magnet 2 to the bottom of the annular magnetic yoke 1 to ensure the formation of the subsequent double holding magnetic circuit. The moving iron core 4 has an inverted T-shaped structure, and its vertical end is a cylindrical structure 4-1 inserted into the through hole 8-1 in the center of the coil frame 8. The cylindrical structure 4-1 is equipped with a tripping spring 12. The lower end of the drive shaft 5 passes through the tripping spring 12 and is fixedly connected to the moving iron core 4. The upper end of the drive shaft 5 passes through the through hole 3-1 and the base plate 6 and is connected to the insulating pull rod 16 of the vacuum circuit breaker, so that the two ends of the tripping spring 12 are respectively pressed against the moving iron core 4 and the base plate 6 or the moving iron core 4 and the stationary iron core.

[0024] When closing the circuit breaker, refer to Figure 2 The magnetic field generated by the energized closing coil 9 forms a closing magnetic circuit 13 on the stationary iron core 3 and the moving iron core 4, causing the moving iron core 4 to overcome the resistance of the opening spring 12 and attract the stationary iron core 3, thereby driving the drive shaft 5 to move upward to complete the closing. After the closing is completed and the power is cut off, the magnetic field generated by the permanent magnet 2 forms a double holding magnetic circuit with the stationary iron core 3, the moving iron core 4, and the annular magnetic yoke 1. Figure 2 (As shown in Figures 14 and 15) Keep the circuit closed;

[0025] When tripping, refer to Figure 1 The magnetic field generated by the reverse energization of the trip coil 7 is opposite to the magnetic field generated by the permanent magnet 2, which weakens the magnetic force generated by the permanent magnet. When the magnetic force is less than the closing holding force of the circuit breaker, the moving iron core 4 drives the drive shaft 5 to move down to complete the tripping under the combined action of the contact spring 17 and the tripping spring 12.

[0026] Reference Figure 1 , 5To further shorten the tripping time, the lower end face of the coil frame 8 has an annular groove 8-2, and a repulsion coil 10 is wound in the annular groove 8-2; a repulsion disk 11 is provided on the moving iron core 4 at a position opposite to the repulsion coil 10. When the repulsion coil 10 and the tripping coil 7 are powered simultaneously, the electromagnetic repulsion force generated by the eddy current effect of the repulsion coil 10 pushes the repulsion disk 11 downward, causing the moving iron core 4 to accelerate downward, thereby driving the drive shaft 5 to move downward quickly, achieving rapid tripping in 1-3ms.

[0027] Reference Figure 4 In order to further reduce the height of the permanent magnet operating mechanism, an annular groove 4-2 is provided on the moving iron core 4 at the position relative to the repulsion coil 10, and the repulsion disk 11 is annular and fixed in the annular groove 4-2.

[0028] Reference Figure 3 For ease of assembly, an annular shoulder 3-2 is provided on the outer periphery of the open end of the stationary iron core 3. The permanent magnet 2 is annular and is fitted around the periphery of the stationary iron core 3, and its lower end sits on the annular shoulder 3-2.

[0029] In order to maintain the closed state, the dual holding magnetic circuit ( Figure 2 The magnetic field lines (as shown in Figures 14 and 15) are evenly distributed, and an annular groove 4-3 is provided on the moving iron core 4 at a position relative to the permanent magnet 2.

[0030] In a specific implementation, the annular magnetic yoke 1 and the stationary iron core 3 are fixedly connected to the lower part of the base plate 6 by screws 18, the lower end of the drive shaft 5 has external threads, and the lower end of the drive shaft 5 is threadedly connected to the moving iron core 4 and then fixed by nuts 19.

[0031] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of implementation of the present utility model. Therefore, all equivalent variations made based on the content described in the claims of the present utility model should be included within the scope of the claims of the present utility model.

Claims

1. A vacuum circuit breaker permanent magnet operating mechanism characterized by: The system includes a base plate (6), on which a ring-shaped magnetic yoke (1) and a stationary iron core (3) are fixedly fixed. The stationary iron core (3) is coaxially arranged in the inner cavity of the ring-shaped magnetic yoke (1). The stationary iron core (3) has a ring structure with a closed upper end and an open lower end, and a through hole (3-1) in the center of its upper end. A tripping coil (7) and a permanent magnet (2) are provided between the stationary iron core (3) and the ring-shaped magnetic yoke (1), and the tripping coil (7) is located above the permanent magnet (2). A coil frame (8) is provided in the inner cavity of the stationary iron core (3), and a closing coil (9) is wound on the coil frame (8). Below the stationary iron core (3) and the annular magnetic yoke (1) is a moving iron core (4). The moving iron core (4) has an inverted T-shaped structure, and its vertical end has a cylindrical structure (4-1) and is inserted into the through hole (8-1) in the center of the coil frame (8). The cylindrical structure (4-1) is equipped with a tripping spring (12). The lower end of the drive shaft (5) passes through the tripping spring (12) and is fixedly connected to the moving iron core (4). The upper end of the drive shaft (5) passes through the through hole (3-1) and the base plate (6) and is connected to the insulating pull rod (16) of the vacuum circuit breaker, so that the two ends of the tripping spring (12) are respectively pressed against the moving iron core (4) and the base plate (6). When closing, the magnetic field generated by the energized closing coil (9) forms a closing magnetic circuit (13) on the stationary iron core (3) and the moving iron core (4), causing the moving iron core (4) to overcome the resistance of the opening spring (12) and attract the stationary iron core (3), thereby driving the drive shaft (5) to move upward to complete the closing. After the closing is completed and the power is cut off, the magnetic field generated by the permanent magnet (2) forms a double holding magnetic circuit with the stationary iron core (3), the moving iron core (4) and the annular yoke (1) to maintain the closing state. When opening, the magnetic field generated by the reverse energization of the opening coil (7) weakens the magnetic force of the permanent magnet (2) so that it is less than the closing holding force of the circuit breaker. Under the combined action of the contact spring (17) and the opening spring (12), the moving iron core (4) drives the drive shaft (5) to move downward to complete the opening.

2. The vacuum circuit breaker permanent magnet operating mechanism according to claim 1, characterized in that: The lower end face of the coil frame (8) has an annular groove (8-2), and a repulsive coil (10) is wound in the annular groove (8-2); a repulsive disk (11) is provided on the moving iron core (4) at a position relative to the repulsive coil (10).

3. The vacuum circuit breaker permanent magnet operating mechanism according to claim 2, characterized in that: The moving iron core (4) is provided with an annular groove (4-2) at a position relative to the repulsion coil (10), and the repulsion disk (11) is annular and fixed in the annular groove (4-2).

4. The vacuum circuit breaker permanent magnet operating mechanism according to claim 1, characterized in that: The static iron core (3) has an annular shoulder (3-2) on the outer periphery of its open end. The permanent magnet (2) is annular and is fitted around the static iron core (3), and its lower end sits on the annular shoulder (3-2).

5. The vacuum circuit breaker permanent magnet operating mechanism according to claim 3, characterized in that: The moving iron core (4) is provided with an annular groove (4-3) at a position relative to the permanent magnet (2).

6. The vacuum circuit breaker permanent magnet operating mechanism according to claim 1, characterized in that: The substrate (6) is made of a non-magnetic material.

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