Quick operating device of permanent magnet vacuum circuit breaker

Abstract

A quick operating device of a permanent magnet vacuum circuit breaker comprises an opening and closing transmission mechanism and a permanent magnet driving mechanism, a cam is horizontally fixed at the end part of a driving rod of the permanent magnet driving mechanism, and a pair of small rollers are mounted on two sides of one end, facing the opening and closing transmission mechanism, of the cam; a large roller is arranged at the cantilever end of a main crank arm of the opening and closing transmission mechanism, a small roller is positioned above the main crank arm, and the large roller is positioned below a cam; during closing, the driving rod of the permanent magnet driving mechanism moves downwards, so that the bottom end of the cam firstly abuts against the top of the large roller, the main crank arm is pushed to swing anticlockwise, the driving rod continues to move downwards, the small roller abuts against the upper edge of the main crank arm, and the main crank arm continues to swing anticlockwise. The main crank arm drives the closing and opening transmission mechanism to complete closing and keeping; and during opening, the driving rod of the permanent magnet driving mechanism moves upwards, so that the small roller is separated from the upper edge of the main crank arm, and the closing and opening transmission mechanism is reset to finish opening.

Description

Technical Field

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

[0002] Currently, similar permanent magnet operating devices all consist of a closing / opening transmission mechanism and a permanent magnet drive mechanism. The drive rod of the permanent magnet drive mechanism is hinged to the main crank arm of the closing / opening transmission mechanism through a linkage mechanism. The drive arm L1 is relatively long and fixed. During operation, the permanent magnet mechanism has a large stroke. According to the principle of permanent magnet mechanisms, the larger the gap, the greater the required drive current, the greater the required electrical energy, and the longer the stroke time, resulting in higher energy consumption. Moreover, due to the large stroke of the permanent magnet mechanism, the circuit breaker's opening and closing time is long.

[0003] In addition, since the drive rod of the permanent magnet drive mechanism is hinged to the main crank arm of the closing and opening transmission mechanism through a linkage mechanism, it is difficult to change the direction of the reaction force of the circuit breaker contact pressure on the moving magnet after closing by adjusting the initial included angle of the main crank arm. This reduces the magnetic holding force required by the moving magnet and improves the operating reliability of the circuit breaker. Utility Model Content

[0004] This invention provides a quick-operation device for a permanent magnet vacuum circuit breaker to overcome the shortcomings of the prior art.

[0005] The technical solution adopted in this utility model is as follows: a rapid operating device for a permanent magnet vacuum circuit breaker, including a closing and opening transmission mechanism and a permanent magnet drive mechanism. A cam is horizontally fixed to the end of the drive rod of the permanent magnet drive mechanism. A pair of small rollers are installed on both sides of the end of the cam facing the closing and opening transmission mechanism. A large roller is installed on the cantilever end of the main crank arm of the closing and opening transmission mechanism, with the small rollers located above the main crank arm and the large roller located below the cam. When closing, the drive rod of the permanent magnet drive mechanism moves downward, causing the bottom end of the cam to first abut against the top of the large roller, pushing the main crank arm to swing counterclockwise. The drive rod continues to move downward, causing the small rollers to abut against the upper edge of the main crank arm, continuing to push the main crank arm to swing counterclockwise. This, in turn, drives the closing and opening transmission mechanism through the main crank arm to complete the closing and hold. When opening, the drive rod of the permanent magnet drive mechanism moves upward, causing the small rollers to disengage from the upper edge of the main crank arm, and the closing and opening transmission mechanism resets to complete the opening.

[0006] A return spring is fitted onto the drive rod, which drives the drive rod to move upward quickly.

[0007] The end of the drive rod is provided with a radial through groove. One end of the cam-back clutch engagement / disengagement transmission mechanism is fitted into the through groove and fixed with rivets. The small roller is mounted on the cam via a horizontal shaft.

[0008] The main crank arm is composed of two parallel wall plates. The large roller is installed between the two wall plates by a horizontal pin, and the outer circle of the large roller protrudes above the two wall plates. The end of the cam facing the opening and closing transmission mechanism extends between the two wall plates, and a pair of small rollers abut against the upper ends of the two wall plates respectively.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] 1. The drive output of the permanent magnet drive mechanism of this utility model is a secondary output. The first output lever arm is relatively long, which saves effort and energy. The second output lever arm is shorter, which increases the ratio of the travel of the moving contact of the vacuum interrupter to the travel of the lever arm, and speeds up the running speed of the moving contact, thereby reducing the operating stroke. This not only improves the operating efficiency, but also shortens the opening and closing operation time of the circuit breaker.

[0011] 2. This utility model can change the direction of the reaction force of the circuit breaker contact pressure on the moving magnet after closing by adjusting the initial included angle of the main crank arm, thereby reducing the magnetic holding force required by the moving magnet and improving the operating reliability of the circuit breaker.

[0012] 3. This utility model accelerates the release of stored energy from the opening spring and contact pressure spring by setting a reset spring to push the drive rod to move upward quickly, thereby speeding up the circuit breaker opening speed and reducing the opening time to ≤5ms. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of the present invention in the closed state;

[0014] Figure 2 This is a cross-sectional view of the circuit breaker in the open state of this utility model;

[0015] Figure 3 This is a transmission diagram of the permanent magnet drive mechanism and the closing / opening transmission mechanism of this utility model;

[0016] Figure 4 This is a schematic diagram of the contact state between the cam and the main crank arm of this utility model;

[0017] Figure 5 This is a cross-sectional schematic diagram of the existing operating device structure. Detailed Implementation

[0018] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in detail with reference to specific embodiments.

[0019] A rapid operating device for a permanent magnet vacuum circuit breaker includes a closing / opening transmission mechanism 1 and a permanent magnet drive mechanism 2. A cam 3 is horizontally fixed to the end of the drive rod 2-1 of the permanent magnet drive mechanism 2. A pair of small rollers 3-1 are mounted on both sides of the end of the cam 3 facing the closing / opening transmission mechanism 1. A large roller 4-1 is mounted on the cantilever end of the main crank arm 4 of the closing / opening transmission mechanism 1, with the small rollers 3-1 located above the main crank arm 4 and the large roller 4-1 located below the cam 3. During closing, the drive rod of the permanent magnet drive mechanism 2... 2-1 moves downward, so that the bottom end of cam 3 first abuts against the top of the large roller 4-1, pushing the main crank arm 4 to swing counterclockwise. The drive rod 2-1 continues to move downward, and the small roller 3-1 abuts against the upper edge of the main crank arm 4, continuing to push the main crank arm 4 to swing counterclockwise. Then, the main crank arm 4 drives the closing and opening transmission mechanism 1 to complete the closing and hold. When opening, the drive rod 2-1 of the permanent magnet drive mechanism 2 moves upward, so that the small roller 3-1 disengages from the upper edge of the main crank arm 4, and the closing and opening transmission mechanism 1 resets to complete the opening.

[0020] The drive output of this utility model's permanent magnet drive mechanism is a secondary output. The first output is when the cam contacts the large roller on the main crank arm, and the lever arm L1 is relatively long. After the drive rod moves a few millimeters, the thrust gradually increases, and the cam disengages from the large roller, while the small roller contacts the main crank arm, and the lever arm L2 becomes shorter. Due to the shortened lever arm, the ratio of the travel of the moving contact of the vacuum interrupter to the travel of the lever arm increases, and the travel speed of the moving contact increases. As the drive rod continues to move downward, the moving and stationary contacts of the vacuum interrupter come into contact, thereby reducing the operating stroke. This not only improves the operating efficiency but also shortens the opening and closing operation time of the circuit breaker.

[0021] In particular, the rolling contact between the cam and the main crank arm results in a longer initial lever arm for the main crank arm, leading to lower energy consumption in the permanent magnet mechanism for the same output driving force, which also helps reduce operating costs. Simultaneously, based on the relationship between the air gap and electromagnetic force, the reduced stroke of the moving magnet in the permanent magnet mechanism (air gap) requires a smaller pulse current to drive the main crank arm. This reduces the current required by the control unit, improving the reliability of the control system and lowering its cost.

[0022] For example, in a conventional permanent magnet mechanism, with L1 remaining constant, for a 10kV vacuum circuit breaker, the opening distance between the moving and stationary contacts of the vacuum interrupter is 9mm, and the overtravel is 3mm, resulting in a permanent magnet mechanism stroke of 16mm-26mm. Using the above technical solution, assuming the opening distance between the moving and stationary contacts of the vacuum interrupter is also 9mm, with an overtravel of 3mm, and L1 remaining constant, adjusting L1 to L2 can reduce the total stroke of the permanent magnet mechanism to 8mm, theoretically increasing the speed by 30-50% and reducing the closing time by 30%.

[0023] Because the cam and the main crank arm use rolling contact, the direction of the reaction force of the circuit breaker contact pressure on the moving magnet after closing can be changed by adjusting the initial angle of the main crank arm. This reduces the magnetic holding force required by the moving magnet and improves the operational reliability of the circuit breaker. By adjusting the angle, the magnetic holding force can be reduced by about 30%. For example, if the original design required a 4800N permanent magnet mechanism, a 3200N permanent magnet mechanism can now meet the requirements.

[0024] In the above embodiments, to shorten the opening time, a return spring 2-2 is fitted on the drive rod 2-1. The return spring 2-2 drives the drive rod 2-1 to move upward quickly. In a specific embodiment, the return spring 2-2 is located inside the permanent magnet drive mechanism 2. After the opening command is triggered, when the electromagnetic force is greater than the permanent magnet force, the return spring pushes the drive rod to move upward quickly, causing the small roller on the cam to quickly disengage from the main crank arm (trip), accelerating the downward movement of the moving contact, causing the moving contact to disengage from the stationary contact at high speed, and the arc in the vacuum interrupter chamber is extinguished when the current crosses zero. The moving magnet returns to the opening position. Due to the addition of the return spring, the energy release of the opening spring and contact pressure spring is accelerated, resulting in a faster circuit breaker opening speed and an opening time ≤ 5ms.

[0025] In the above embodiment, the end of the drive rod 2-1 is provided with a through groove in the radial direction, one end of the cam 3 is engaged in the through groove and fixed by a rivet, and the small roller 3-1 is mounted on the cam 3 by a horizontal shaft.

[0026] In the above embodiment, the main crank arm 4 is composed of two parallel wall plates 4-2. The large roller 4-1 is installed between the two wall plates 4-2 by a horizontal pin, and the outer circle of the large roller 4-1 protrudes above the two wall plates 4-2. The cam 3 extends into the space between the two wall plates 4-2 at one end facing the brake opening and closing transmission mechanism 1, and a pair of small rollers 3-1 respectively abut against the upper ends of the two wall plates 4-2.

[0027] In the above embodiments, the specific structures of the closing and opening transmission mechanism 1 and the permanent magnet drive mechanism 2 are basically the same as those in the prior art, and will not be described again.

[0028] 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 rapid operating device for a permanent magnet vacuum circuit breaker, comprising a closing / opening transmission mechanism (1) and a permanent magnet drive mechanism (2), characterized in that: The permanent magnet drive mechanism (2) has a cam (3) fixed horizontally at the end of the drive rod (2-1). A pair of small rollers (3-1) are installed on both sides of the end of the cam (3) facing the closing and opening transmission mechanism (1). A large roller (4-1) is installed on the cantilever end of the main crank arm (4) of the closing and opening transmission mechanism (1). The small roller (3-1) is located above the main crank arm (4), and the large roller (4-1) is located below the cam (3). When closing, the drive rod (2-1) of the permanent magnet drive mechanism (2) moves downward, so that the bottom of the cam (3) The first end abuts against the top of the large roller (4-1), pushing the main crank arm (4) to swing counterclockwise. The drive rod (2-1) continues to move downward, and the small roller (3-1) abuts against the upper edge of the main crank arm (4), continuing to push the main crank arm (4) to swing counterclockwise. Then, the main crank arm (4) drives the closing and opening transmission mechanism (1) to complete the closing and hold. When opening, the drive rod (2-1) of the permanent magnet drive mechanism (2) moves upward, causing the small roller (3-1) to disengage from the upper edge of the main crank arm (4), and the closing and opening transmission mechanism (1) resets to complete the opening.

2. The operating device according to claim 1, characterized in that: A return spring (2-2) is fitted on the drive rod (2-1), and the drive rod (2-1) is driven to move upward quickly by the return spring (2-2).

3. The actuator of claim 1, wherein: The end of the drive rod (2-1) is provided with a through groove in the radial direction. One end of the cam (3) opposite to the clutch opening and closing transmission mechanism (1) is fitted in the through groove and fixed by rivets. The small roller (3-1) is mounted on the cam (3) through a horizontal shaft.

4. The actuator of claim 3, wherein: The main crank arm (4) is composed of two parallel wall plates (4-2). The large roller (4-1) is installed between the two wall plates (4-2) by a horizontal pin, and the outer circle of the large roller (4-1) protrudes above the two wall plates (4-2). The cam (3) extends into the space between the two wall plates (4-2) at one end facing the opening and closing transmission mechanism (1), and a pair of small rollers (3-1) abut against the upper ends of the two wall plates (4-2) respectively.

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