An adjustable single-phase direct-acting permanent magnet mechanism and a permanent magnet vacuum circuit breaker

Abstract

This application discloses an adjustable single-phase direct-acting permanent magnet mechanism and a permanent magnet vacuum circuit breaker, belonging to the technical field of permanent magnet mechanisms. It includes a stationary end plate and a moving end plate arranged in parallel. A permanent magnet assembly is disposed on the side of the stationary end plate opposite to the moving end plate. A moving iron core is axially movable between the permanent magnet assembly and the moving end plate. The moving iron core achieves axial movement through a tripping spring and a coil disposed on the side of the moving iron core opposite to the stationary end plate. A pull rod is disposed on the moving iron core, with its tip passing through the stationary end plate. Movement of the pull rod can drive the moving contact in the arc-extinguishing chamber to move. A stroke adjustment shim is disposed between the moving end plate and the moving iron core. It also includes an overtravel adjustment shim for adjusting the distance between the tip of the pull rod and the moving iron core. This application allows for precise adjustment of the overtravel when dealing with pole-mounted permanent magnet vacuum circuit breakers with different rated breaking currents, by replacing the overtravel adjustment shims and stroke adjustment shims of different thicknesses.

Description

Technical Field

[0001] This application relates to the field of permanent magnet mechanism technology, and in particular to an adjustable single-phase direct-acting permanent magnet mechanism and a permanent magnet vacuum circuit breaker. Background Technology

[0002] Currently, there are two transmission methods between the vacuum interrupter and the permanent magnet mechanism in traditional 10kV pole-mounted permanent magnet vacuum circuit breakers. One method is the "pull-close-top-open" connection, where the interrupter and mechanism are connected via an adjusting screw. This method allows adjustment of the total stroke, but its drawback is that the minimum adjustment value for overtravel and opening distance is 0.5 times the screw pitch, making it difficult to precisely achieve the ideal overtravel value. The second method is the direct-acting connection. This method allows for the adjustment of overtravel and opening distance as needed, but its disadvantages are also obvious. The total stroke is limited to a fixed value by a stop buffer, and because of the correlation between overtravel and opening distance, their adjustments are mutually restrictive and cannot be performed independently. If the overtravel is too small, the contact pressure after the circuit breaker closes cannot be guaranteed, resulting in a lower initial opening speed, affecting the breaking, closing, and dynamic and thermal stability performance, and even causing reclosing bounce. If the overtravel is too large, it increases the closing power of the operating mechanism, reducing closing reliability and shortening the lifespan of the interrupter.

[0003] In addition, the rated breaking current of the commonly used 10kV pole-mounted permanent magnet vacuum circuit breakers on the market is 20kA and 25kA, which requires the use of corresponding arc-extinguishing chambers. For arc-extinguishing chambers with different rated breaking currents, the requirements for rated contact pressure are different, while the opening distance range remains unchanged. This requires the overtravel to be increased or decreased accordingly, which may require redesigning the component dimensions, fitting dimensions, or replacing components. Summary of the Invention

[0004] The purpose of this application is to provide an adjustable single-phase direct-acting permanent magnet mechanism and a permanent magnet vacuum circuit breaker to solve the problem in the prior art where the direct-acting connection of the vacuum interrupter and the permanent magnet mechanism restricts each other and cannot be adjusted independently.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0006] On one hand, this application provides an adjustable single-phase direct-acting permanent magnet mechanism, comprising a stationary end plate and a moving end plate arranged in parallel, and further including:

[0007] A permanent magnet assembly is disposed on the side of the stationary end plate relative to the moving end plate;

[0008] A moving iron core is axially movable between the permanent magnet assembly and the moving end plate;

[0009] A coil, when energized, generates an induced magnetic field, causing the moving iron core to move axially.

[0010] A tripping spring is disposed on the side of the moving iron core relative to the stationary end plate;

[0011] A pull rod is connected to the moving iron core. The top end of the pull rod passes through the stationary end plate. Moving the pull rod can drive the moving contact in the arc-extinguishing chamber to move.

[0012] A stroke adjustment shim is disposed between the moving end plate and the moving iron core;

[0013] An overtravel adjustment shim is used to adjust the distance between the top of the pull rod and the moving iron core.

[0014] When the circuit breaker is closed, the operating coil is supplied with a closing current, generating an induced magnetic field identical to that of the permanent magnet assembly. Under the influence of the permanent magnet assembly and the induced magnetic field, the moving iron core overcomes the forces of the opening spring and the external circuit breaker contact spring, moving towards the permanent magnet assembly. When the moving iron core attracts the permanent magnet assembly, the circuit breaker is closed. Similarly, when the circuit breaker is closed, the operating coil is supplied with a opening current, generating an induced magnetic field opposite to that of the permanent magnet assembly. Under the forces of the opening spring and the contact spring, the moving iron core moves towards the moving end plate.

[0015] The adjustable single-phase direct-acting permanent magnet mechanism in this solution can flexibly adjust the total stroke, overtravel, and opening distance, as detailed below:

[0016] Stroke adjustment: This solution moves the moving iron core by moving the moving rod, which in turn moves the moving contact in the arc-extinguishing chamber. The distance the moving iron core moves is the total stroke. By setting stroke adjustment shims of different thicknesses or numbers between the moving end plate and the moving iron core, the axial movement distance of the moving iron core can be adjusted, that is, the total stroke can be adjusted.

[0017] Synchronous adjustment of overtravel and opening distance: This scheme also adjusts the distance between the top of the pull rod and the moving iron core by setting an overtravel adjustment shim. With the total stroke remaining constant, when the distance between the top of the pull rod and the moving iron core increases, the distance between the top of the pull rod and the moving contact decreases, i.e., the opening distance decreases. Since the pull rod's movement distance remains constant, the overtravel increases. Conversely, with the total stroke remaining constant, when the distance between the top of the pull rod and the moving iron core decreases, the distance between the top of the pull rod and the moving contact increases, i.e., the opening distance increases. Since the pull rod's movement distance remains constant, the overtravel decreases.

[0018] Overtravel and opening distance asynchronous adjustment: When dealing with pole-mounted permanent magnet vacuum circuit breakers with different rated breaking currents, under the condition of constant opening distance, the overtravel can be adjusted by setting overtravel adjustment shims and stroke adjustment shims of different thicknesses.

[0019] When it is necessary to reduce overtravel, first replace the thicker stroke adjusting shims or increase the number of stroke adjusting shims to reduce the total stroke. Then, replace the thinner overtravel adjusting shims or reduce the number of overtravel adjusting shims. It is important to note that the increase in thickness of the stroke adjusting shims should be the same as the decrease in thickness of the overtravel adjusting shims to ensure that the top position of the pull rod remains unchanged, i.e., the opening distance remains unchanged. In this scheme, because the total stroke of the moving iron core decreases, the movement distance of the pull rod decreases, i.e., the overtravel is reduced.

[0020] Conversely, when increased overtravel is required, first replace the thinner stroke adjusting shims or reduce the number of stroke adjusting shims to increase the total stroke. Then, replace the thicker overtravel adjusting shims or increase the number of overtravel adjusting shims. It is important to note that the reduction in thickness of the stroke adjusting shims should be the same as the increase in thickness of the overtravel adjusting shims to ensure that the top position of the pull rod remains unchanged, i.e., the opening distance remains constant. In this scheme, because the total stroke of the moving iron core increases, the movement distance of the pull rod increases, i.e., the overtravel increases.

[0021] When dealing with pole-mounted permanent magnet vacuum circuit breakers with different rated breaking currents, the overtravel can be precisely adjusted by replacing the overtravel adjustment shims and stroke adjustment shims with different thicknesses.

[0022] In summary, the adjustable single-phase direct-acting permanent magnet mechanism of this application, through its flexible stroke and overtravel adjustment mechanism, enables adaptation to circuit breakers with different rated breaking currents, thereby improving the versatility and practicality of the equipment.

[0023] Optionally, the pull rod includes a coaxial first rod portion and a second rod portion, the diameter of the first rod portion is larger than the diameter of the second rod portion, the second rod portion has a thread, the second rod portion passes through the moving iron core and is connected to the moving iron core by a nut, and the overtravel adjustment shim is sleeved on the second rod portion and located between the first rod portion and the moving iron core.

[0024] Optionally, the stroke adjustment shim is fitted onto the second rod portion.

[0025] In this design, the stroke adjustment shim is fitted onto the second rod to adjust the distance between the moving iron core and the moving end plate, thereby adjusting the distance between the moving iron core and the permanent magnet assembly, i.e., adjusting the total stroke.

[0026] Optionally, the stationary end plate and the moving end plate are connected by several connecting rods, and the stroke adjustment shim is sleeved on the connecting rod.

[0027] Optionally, the permanent magnet assembly includes: a magnetic yoke, a permanent magnet, and a stationary iron core nested sequentially from the outside in. The magnetic yoke is typically made of a magnetically conductive material (such as iron or an iron alloy) and is used to guide and concentrate the magnetic field. In this embodiment, the magnetic yoke surrounds the permanent magnet, forming a closed magnetic circuit, which helps to enhance and stabilize the magnetic field generated by the permanent magnet. Furthermore, the permanent magnet is used to generate the magnetic field. In this embodiment, the permanent magnet is made of neodymium iron boron. Furthermore, the stationary iron core is also made of a magnetically conductive material, corresponding to the moving iron core. In the closed state, the stationary iron core and the moving iron core attract each other through the magnetic field, forming a stable magnetic circuit.

[0028] On the other hand, this application provides a permanent magnet vacuum circuit breaker, including the above-mentioned adjustable single-phase direct-acting permanent magnet mechanism.

[0029] Compared with the prior art, the beneficial effects achieved by this application are as follows: This application moves the moving iron core to drive the pull rod, which in turn moves the moving contact in the arc-extinguishing chamber. The moving distance of the moving iron core is the total stroke. By setting stroke adjustment shims of different thicknesses or numbers between the moving end plate and the moving iron core, the axial movement distance of the moving iron core can be adjusted, that is, the total stroke can be adjusted. This application adjusts the distance between the top of the pull rod and the moving iron core by setting overtravel adjustment shims. Under the condition that the total stroke remains unchanged, the overtravel and opening distance can be adjusted by setting overtravel adjustment shims of different thicknesses.

[0030] This application addresses the issue of pole-mounted permanent magnet vacuum circuit breakers with varying rated breaking currents by using overtravel and travel adjustment shims of different thicknesses, thereby achieving overtravel adjustment while maintaining a constant opening distance. By adjusting the travel, opening distance, and overtravel, the application enables adaptation to circuit breakers with different rated breaking currents, improving the equipment's versatility and practicality. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 These are schematic diagrams of the closing states of some embodiments provided in this application;

[0033] Figure 2 This is a schematic diagram of the tripped state of some embodiments provided in this application.

[0034] Explanation of reference numerals in the attached drawings: 1-Stationary end plate; 2-Moving end plate; 3-Permanent magnet assembly; 4-Moving iron core; 5-Coil; 6-Break spring; 7-Pull rod; 8-Stroke adjustment shim; 9-Overtravel adjustment shim; 10-Connecting rod; 31-Magnetic yoke; 32-Permanent magnet; 33-Stationary iron core; 41-Coil slot; 71-First rod section; 72-Second rod section. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure / application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use.

[0036] The technical terms used in this application are explained below:

[0037] Overtravel refers to the additional distance the moving contact moves relative to the stationary contact after the circuit breaker contacts have closed. This additional movement is to ensure tight contact between the contacts in the closed state and to provide sufficient contact pressure, thereby maintaining good electrical connection and mechanical stability. The magnitude of the overtravel directly affects the closing reliability of the circuit breaker and contact wear. Insufficient overtravel may lead to poor contact, increased resistance and heat generation, and even arcing. Excessive overtravel may increase the burden on the operating mechanism, reduce the closing speed, and even affect the lifespan of the circuit breaker.

[0038] The opening distance refers to the minimum distance between the moving and stationary contacts of a circuit breaker when the circuit breaker is in the open state. This distance is to prevent arcing between the contacts when the circuit breaker is open, thereby protecting the equipment and system. The size of the opening distance depends on the rated voltage and rated current of the circuit breaker, as well as the arc-extinguishing medium and arc-extinguishing method used.

[0039] Total stroke refers to the total distance the moving contact of a circuit breaker moves from the closed position to the open position (or vice versa). This distance includes overtravel and opening distance, as well as other minor displacements that the moving contact may experience during the movement. The magnitude of the total stroke is crucial to the design of the circuit breaker's operating and transmission mechanisms. It determines the mechanical energy and operating time required by the circuit breaker during closing and opening, thus affecting the circuit breaker's performance and reliability.

[0040] Example 1

[0041] This embodiment describes an adjustable single-phase direct-acting permanent magnet mechanism, referencing... Figure 1 and Figure 2The adjustable single-phase direct-acting permanent magnet mechanism in this embodiment includes a stationary end plate 1 and a moving end plate 2 arranged in parallel, connected by four connecting rods 10. A permanent magnet assembly 3 is disposed on the side of the stationary end plate 1 opposite to the moving end plate 2. A moving iron core 4 is disposed between the permanent magnet assembly 3 and the moving end plate 2, and the moving iron core 4 is capable of axial movement between them. Furthermore, the moving iron core 4 has a closed state (attracted to the permanent magnet assembly 3) and a closed state (separated from the permanent magnet assembly 3).

[0042] In this embodiment, the moving iron core 4 is closed and opened via coil 5 and opening spring 6. Specifically, coil 5 generates an induced magnetic field by being energized, causing the moving iron core 4 to move axially. The opening spring 6 is located on the side of the moving iron core 4 relative to the stationary end plate 1, and exerts a force on the moving iron core 4 towards the moving end plate 2. When closing, the operating coil 5 is energized with a closing current, generating the same induced magnetic field as the permanent magnet assembly 3. Under the action of the permanent magnet assembly 3 and the induced magnetic field, the moving iron core 4 overcomes the force of the opening spring 6 and the external circuit breaker contact spring, moving towards the permanent magnet assembly 3. When the moving iron core 4 is attracted to the permanent magnet assembly 3, the closed state is achieved. Similarly, when in the closed state, the operating coil 5 is energized with a opening current, generating an induced magnetic field opposite to that of the permanent magnet assembly 3. Under the action of the opening spring 6 and the contact spring, the moving iron core 4 moves towards the moving end plate 2.

[0043] Furthermore, a pull rod 7 is connected to the moving iron core 4. The top of the pull rod 7 passes through the stationary end plate 1. Moving the pull rod 7 can drive the moving contact in the arc-extinguishing chamber to move. The movement of the moving iron core can drive the pull rod 7 to move, which in turn drives the moving contact to move.

[0044] This embodiment also achieves adjustment of total stroke, overtravel, and opening distance by setting stroke adjustment shims 8 and overtravel adjustment shims 9. Specifically, the stroke adjustment shim 8 is set between the moving end plate 2 and the moving iron core 4. The overtravel adjustment shim 9 is sleeved on the connecting rod 10 and is used to adjust the distance between the top of the pull rod 7 and the moving iron core 4. The adjustment method is as follows:

[0045] Stroke adjustment: In this scheme, the moving iron core 4 moves the moving rod 7, which in turn drives the moving contact in the arc-extinguishing chamber to move. The distance the moving iron core 4 moves is the total stroke. By setting stroke adjustment shims 8 of different thicknesses or numbers between the moving end plate 2 and the moving iron core 4, the axial movement distance of the moving iron core 4 can be adjusted, that is, the total stroke can be adjusted.

[0046] Synchronous adjustment of overtravel and opening distance: This scheme also adjusts the distance between the top of the pull rod 7 and the moving iron core 4 by setting an overtravel adjustment shim 9. With the total stroke remaining constant, when the distance between the top of the pull rod 7 and the moving iron core 4 increases, the distance between the top of the pull rod 7 and the moving contact decreases, i.e., the opening distance decreases. Since the movement distance of the pull rod 7 remains constant, the overtravel increases. Conversely, with the total stroke remaining constant, when the distance between the top of the pull rod 7 and the moving iron core 4 decreases, the distance between the top of the pull rod 7 and the moving contact increases, i.e., the opening distance increases. Since the movement distance of the pull rod 7 remains constant, the overtravel decreases.

[0047] Overtravel and opening distance asynchronous adjustment: When dealing with pole-mounted permanent magnet vacuum circuit breakers with different rated breaking currents, under the condition of constant opening distance, the overtravel can be adjusted by setting overtravel adjustment shims 9 and stroke adjustment shims 8 with different thicknesses.

[0048] When it is necessary to reduce overtravel, first replace the thicker stroke adjusting shim 8 or increase the number of stroke adjusting shims 8 to reduce the total stroke. Then, replace the thinner overtravel adjusting shim 9 or reduce the number of overtravel adjusting shims 9. It is important to note that the increase in thickness of the stroke adjusting shim 8 should be the same as the decrease in thickness of the overtravel adjusting shim 9 to ensure that the top position of the pull rod 7 remains unchanged, i.e., the opening distance remains unchanged. In this scheme, because the total stroke of the moving iron core 4 decreases, the movement distance of the pull rod 7 decreases, i.e., the overtravel is reduced.

[0049] Conversely, when increased overtravel is required, first replace the thinner stroke adjusting shim 8 or reduce the number of stroke adjusting shims 8 to increase the total stroke. Then, replace the thicker overtravel adjusting shim 9 or increase the number of overtravel adjusting shims 9. It is important to note that the reduction in thickness of the stroke adjusting shim 8 should be the same as the increase in thickness of the overtravel adjusting shim 9 to ensure that the top position of the pull rod 7 remains unchanged, i.e., the opening distance remains unchanged. In this scheme, because the total stroke of the moving iron core 4 increases, the movement distance of the pull rod 7 increases, i.e., the overtravel increases.

[0050] When dealing with pole-mounted permanent magnet vacuum circuit breakers with different rated breaking currents, the overtravel can be precisely adjusted by replacing the overtravel adjustment shim 9 and the stroke adjustment shim 8 with shims of different thicknesses.

[0051] Example 2:

[0052] Based on the same inventive concept as Embodiment 1, refer to Figure 1 and Figure 2 In this embodiment, the pull rod 7 includes a first rod portion 71 and a second rod portion 72 that are coaxial. The diameter of the first rod portion 71 is larger than the diameter of the second rod portion 72. The second rod portion 72 has threads. The second rod portion 72 passes through the moving iron core 4 and is connected to the moving iron core 4 through a nut. The overtravel adjustment shim 9 is sleeved on the second rod portion and is located between the first rod portion 71 and the moving iron core 4.

[0053] In this embodiment, the stroke adjustment shim 8 is sleeved on the second rod portion 72. The stroke adjustment shim 8 is sleeved on the second rod portion 72 to adjust the distance between the moving iron core 4 and the moving end plate 2, thereby adjusting the distance between the moving iron core 4 and the permanent magnet assembly 3, that is, adjusting the total stroke.

[0054] In this embodiment, the permanent magnet assembly 3 includes a magnetic yoke 31, a permanent magnet 32, and a stationary iron core 33, nested sequentially from the outside in. The magnetic yoke 31 is typically made of a magnetically conductive material (such as iron or an iron alloy) and is used to guide and concentrate the magnetic field. In this embodiment, the magnetic yoke 31 surrounds the permanent magnet 32, forming a closed magnetic circuit, which helps to enhance and stabilize the magnetic field generated by the permanent magnet 32. Furthermore, the permanent magnet 32 ​​is used to generate the magnetic field. In this embodiment, the permanent magnet is made of neodymium iron boron. Furthermore, the stationary iron core 33 is also made of a magnetically conductive material and corresponds to the moving iron core 4. In the closed state, the stationary iron core 33 and the moving iron core 4 attract each other through the magnetic field, forming a stable magnetic circuit.

[0055] In this embodiment, the coil 5 is axially disposed on the side of the stationary iron core 33 and the permanent magnet relative to the moving iron core 4, and the moving iron core 4 defines a coil slot 41 to accommodate the coil 5.

[0056] In this embodiment, there are multiple travel adjusting shims 8, and the thicknesses of these shims 8 conform to an arithmetic sequence with a tolerance of 0.1 mm. The number of overtravel adjusting shims 9 is the same as that of the travel adjusting shims 8, and their thicknesses correspond one-to-one. The contact opening distance of a 10kV pole-mounted permanent magnet vacuum circuit breaker is typically 8~12 mm. This range is to ensure sufficient insulation strength and arc extinguishing capability. In this embodiment, the minimum thickness difference between each travel adjusting shim 8 and each overtravel adjusting shim 9 is 0.1 mm. Precise control of the total travel and overtravel is achieved through the combination of overtravel adjusting shims 9 and travel adjusting shims 8, ensuring the reliability of the circuit breaker's performance.

[0057] Example 3

[0058] This embodiment introduces a permanent magnet vacuum circuit breaker, including the adjustable single-phase direct-acting permanent magnet mechanism as described in Embodiment 1 or Embodiment 2.

[0059] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this disclosure / application, and these improvements and modifications should also be considered within the protection scope of this disclosure / application.

Claims

1. An adjustable single-phase direct-acting permanent magnet mechanism comprising: The stationary end plate (1) and the moving end plate (2) are arranged in parallel, characterized in that they further include: A permanent magnet assembly (3) is disposed on the side of the stationary end plate (1) relative to the moving end plate (2); The moving iron core (4) is axially movable between the permanent magnet assembly (3) and the moving end plate (2); The coil (5) generates an induced magnetic field by being energized, causing the moving iron core (4) to move axially; The tripping spring (6) is disposed on the side of the moving iron core (4) relative to the stationary end plate (1); A pull rod (7) is connected to the moving iron core (4). The top end of the pull rod (7) passes through the stationary end plate (1). The movement of the pull rod (7) can drive the moving contact in the arc-extinguishing chamber to move. A stroke adjustment shim (8) is disposed between the moving end plate (2) and the moving iron core (4); An overtravel adjustment shim (9) is used to adjust the distance between the top of the pull rod (7) and the moving iron core (4).

2. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 1, characterized in that, The pull rod (7) includes a first rod part (71) and a second rod part (72) on the same axis. The diameter of the first rod part (71) is larger than that of the second rod part (72). The second rod part (72) has a thread. The second rod part (72) passes through the moving iron core (4) and is connected to the moving iron core (4) by a nut. The overtravel adjustment shim (9) is sleeved on the second rod part and is located between the first rod part (71) and the moving iron core (4).

3. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 2, characterized in that, The stroke adjustment shim (8) is fitted onto the second rod (72).

4. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 1, characterized in that, The stationary end plate (1) and the moving end plate (2) are connected by several connecting rods (10), and the stroke adjustment shim (8) is sleeved on the connecting rod (10).

5. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 1, characterized in that, The permanent magnet assembly (3) includes a magnetic yoke (31), a permanent magnet (32), and a stationary iron core (33) arranged in a nested manner from the outside to the inside.

6. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 5, characterized in that, The coil (5) is axially disposed on the side of the stationary iron core (33) and the permanent magnet relative to the moving iron core (4), and the moving iron core (4) defines a coil slot (41) to accommodate the coil (5).

7. The adjustable single-phase direct-acting permanent magnet mechanism according to claim 1, characterized in that, There are multiple stroke adjustment shims (8), and the thickness of the multiple stroke adjustment shims (8) satisfies an arithmetic sequence with a tolerance of 0.1 mm. The number of overtravel adjustment shims (9) is the same as that of the stroke adjustment shims (8), and their thicknesses correspond one-to-one.

8. A permanent magnet vacuum circuit breaker, characterized in that, Includes the adjustable single-phase direct-acting permanent magnet mechanism as described in any one of claims 1-7.

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