Transmission mechanism driven by repulsive force and hydraulic pressure stage by stage and circuit breaker with same

Abstract

The invention discloses a transmission mechanism driven by repulsive force and hydraulic pressure stage by stage and a circuit breaker with the same. The transmission mechanism comprises a working cylinder, the hydraulic control valve comprises a valve body and a valve element. A normal low-pressure oil cavity, a working oil cavity and a normal high-pressure oil cavity are formed in the valve body; the working oil cavity is communicated with the lower part of the working cylinder oil cavity to hydraulically drive the piston rod; the valve element is arranged in the working oil cavity and can slide up and down to control connection and disconnection between the working oil cavity and the normal low-pressure oil cavity and between the working oil cavity and the normal high-pressure oil cavity. The electromagnetic repulsion mechanism comprises a base, an ejector rod and a repulsion coil; the lower end of the ejector rod is fixed to the valve element, and the upper end of the ejector rod is connected with the upper end of a piston rod of the working cylinder through a connecting piece. The repulsive force coil is fixed on the top surface of the base and can generate electromagnetic repulsive force with the ejector rod after being electrified. According to the invention, organic fusion of the electromagnetic repulsion mechanism and the working cylinder is realized, and a new solution is provided for further shortening the opening time of the ultrahigh-voltage quick circuit breaker.

Description

Technical Field

[0001] This invention relates to the field of high-voltage switchgear technology, and more specifically to a repulsive force and hydraulic graded drive transmission mechanism and a circuit breaker having the same. Background Technology

[0002] Conventional ultra-high voltage circuit breakers primarily employ hydraulic mechanisms, using tripping electromagnets for tripping, resulting in tripping times as long as 19-21 milliseconds. Hydraulic mechanisms using conventional tripping electromagnets cannot meet the requirements for rapid tripping for two reasons: first, the electromagnet has a large number of turns and a small wire diameter, leading to a long inherent response time; second, due to the limited output force of the electromagnet, it cannot directly drive the main control valve. Its structure employs a multi-stage control amplification method, from energizing the electromagnet coil to actuating the moving iron core, the first-stage valve, the second-stage valve, and finally the main valve, resulting in an inherently long action time.

[0003] To achieve rapid tripping, the operating mechanisms of medium and low voltage fast circuit breakers generally employ electromagnetic repulsion mechanisms. Chinese invention patent application CN105470041A discloses a fast high-voltage switch that uses multiple vacuum interrupters and multiple sets of electromagnetic repulsion mechanisms. The vacuum interrupters are connected in series, with each vacuum interrupter connected to one set of electromagnetic repulsion mechanisms. This multi-break series connection increases the insulation break distance, allowing it to withstand higher voltages. However, the use of multiple interrupters results in a very complex overall circuit breaker structure, increasing its size and reducing operational reliability. Therefore, it is not yet suitable for engineering applications and cannot currently be used in ultra-high voltage circuit breakers.

[0004] In recent years, rapid tripping schemes using electromagnetic repulsion tripping devices in hydraulic mechanisms have been proposed. For example, the hydraulic operating mechanism and hydraulic control valve disclosed in Chinese invention patent application CN112503043A replace the traditional tripping electromagnet with an electromagnetic repulsion tripping device, directly driving the valve stem of the hydraulic control valve to achieve rapid oil circuit switching. The mechanism start-up time is shortened to less than 4ms. Then, the piston rod of the hydraulic mechanism drives the moving contact of the arc-extinguishing chamber to complete the rapid tripping operation, achieving a tripping time of ≤9ms. However, compared with fast vacuum circuit breakers equipped with repulsion mechanisms, the tripping time is still relatively long, and the repulsion mechanism requires a buffer structure to reduce speed and stop at the end, resulting in a significant waste of energy.

[0005] Therefore, how to provide a transmission mechanism that can quickly switch oil circuits and a circuit breaker that can quickly trip is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a transmission mechanism driven by repulsion force and hydraulic staged drive, and a circuit breaker having the same. During the opening operation, the electromagnetic repulsion mechanism realizes the oil circuit switching of the hydraulic control valve, causing the piston rod to move and drive the contacts of the arc-extinguishing chamber to separate, thereby realizing the opening operation of the circuit breaker.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A repulsive force and hydraulic graded drive transmission mechanism, comprising: Working cylinder; A hydraulic control valve includes a valve body and a valve core. The valve body is bolted to the upper end of the working cylinder. The valve body contains, from top to bottom, a constant low-pressure oil chamber, a working oil chamber, and a constant high-pressure oil chamber. The working oil chamber is connected to the lower part of the working cylinder's oil chamber via an oil circuit to hydraulically drive a piston rod. The valve core is located within the working oil chamber and can slide up and down to control the connection / disconnection between the working oil chamber and the constant low-pressure and constant high-pressure oil chambers. An electromagnetic repulsion mechanism includes a base, a push rod, and a repulsion coil. The base is fixed to the upper end of the valve body. The push rod is slidably connected to the base, with its lower end fixed to the valve core and its upper end connected to the upper end of the piston rod of the working cylinder via a connector. The repulsion coil is fixed to the top surface of the base and generates electromagnetic repulsion between itself and the push rod when energized.

[0008] The beneficial effects of the technical solution of this invention are as follows: When the repulsion coil is not energized, the working oil chamber is connected to the constant high-pressure oil chamber. The high-pressure oil in the constant high-pressure oil chamber enters the working cylinder's oil chamber from bottom to top through the working oil chamber. The oil pressure in the working cylinder's oil chamber is balanced, and the piston rod does not move. When the repulsion coil is energized, it generates an electromagnetic repulsion force with the push rod, pushing the valve core downward. In this state, the working oil chamber is connected to the constant low-pressure oil chamber. Low-pressure oil enters the oil chamber from the bottom of the working cylinder. In this state, the upper part of the oil chamber is high-pressure oil, and the lower part of the oil chamber is low-pressure oil. There is an oil pressure difference in the oil chamber. Therefore, when the valve core moves downward, the piston rod can be driven to move downward synchronously through the push rod. This invention realizes the oil circuit switching of the hydraulic control valve through the electromagnetic repulsion mechanism, thereby driving the piston rod to move.

[0009] Preferably, the connecting member is a push plate, one end of which is fixed to the upper outer wall of the piston rod, and the other end of which is sleeved on the top rod. The push plate connects the top rod and the piston rod, realizing the linkage between the top rod and the piston rod.

[0010] Preferably, the electromagnetic repulsion mechanism further includes a metal disk fixed to the upper end of the push rod. When the repulsion coil is energized, it generates electromagnetic repulsion with the metal disk. A push plate is located below the metal disk, and a through hole is formed at the end of the push plate away from the piston rod, which is then fitted onto the push rod. The inner wall of the through hole slides against the outer wall of the push rod. Since one end of the push plate is fixed to the piston rod, when the repulsion coil is energized, the metal disk causes the push rod to move downwards. When the metal disk contacts the push plate, it causes the piston rod to move downwards. After the push rod reaches its stroke limit, due to the oil pressure difference within the working cylinder, the piston rod continues to move downwards. In this state, the push plate slides along the push rod, achieving graded driving of the piston rod through electromagnetic repulsion and the oil pressure difference within the cylinder.

[0011] Preferably, the hydraulic control valve further includes a valve stem slidably connected to the valve body; a valve core is fixed to the valve stem; and a push rod is coaxially arranged with the valve stem, with its lower end fixed to the upper end of the valve stem. Connecting the valve core to the valve stem and fixing the valve stem to the push rod reduces the length of the push rod.

[0012] Preferably, the valve further includes an upper valve sleeve and a lower valve sleeve; the upper valve sleeve is fixed to the upper inner wall of the valve body, and its inner cavity forms the constant low-pressure oil chamber; the lower valve sleeve is fixed to the lower inner wall of the valve body, and its inner cavity forms the constant high-pressure oil chamber; the lower end face of the upper valve sleeve, the upper end face of the lower valve sleeve, and the inner wall of the valve body together form the working oil chamber, and the circumferential surface and sliding surface of the valve core form a sealing surface with the bottom surface of the upper valve sleeve or the top surface of the lower valve sleeve. The valve core can form a sealing surface with the upper and lower valve sleeves to prevent overflow between high-pressure oil and low-pressure oil and ensure the stability of the oil in the working oil chamber.

[0013] Preferably, the valve body has a connecting flow channel; there is a moving gap between the lower end of the valve stem and the inner bottom wall of the valve body; the connecting flow channel connects the working oil chamber and the moving gap. When the push rod reaches its stroke position, the repulsion coil is de-energized, the electromagnetic repulsion disappears, and the high-pressure oil in the constant high-pressure oil chamber pushes the valve core upward to move the push rod upward. As the push rod moves upward, the high-pressure oil in the working oil chamber enters the moving gap, achieving rapid reset of the push rod.

[0014] Preferably, the device further includes a control circuit electrically connected to the repulsive coil; the control circuit includes a switch and a capacitor; closing the switch causes the capacitor to discharge into the repulsive coil. The control circuit enables the repulsive coil to open and close.

[0015] Preferably, the working cylinder includes a cylinder body, on which a working flow channel is formed; the piston rod is slidably connected in the oil chamber of the cylinder body; the working flow channel connects the working oil chamber and the oil chamber of the cylinder body.

[0016] Preferably, both the hydraulic control valve and the electromagnetic repulsion mechanism are provided in two sets and symmetrically arranged at the upper end of the cylinder. The piston rod is driven by the two sets of hydraulic control valves and the electromagnetic repulsion mechanism together, achieving rapid transmission.

[0017] The present invention also provides a circuit breaker that employs a repulsive force and hydraulic graded drive transmission mechanism as described above, wherein the upper end of the piston rod can abut against the contacts in the arc-extinguishing chamber. The repulsion coil is not energized, the working oil chamber is connected to the constant high-pressure oil chamber, the oil chamber of the working cylinder contains high-pressure oil, the upper end of the piston rod abuts against the contact, and the circuit breaker is in the closed position. When the repulsion coil is energized, it pushes the valve core downward, causing the working oil chamber to connect with the constant low-pressure oil chamber, so that there is an oil pressure difference in the oil chamber of the working cylinder. During the downward movement of the valve core, the piston rod is driven to move downward through the oil pressure difference, causing the piston rod to separate from the contact, and the circuit breaker is in the open position.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a transmission mechanism and a circuit breaker with repulsion and hydraulic staged drive. The electromagnetic repulsion mechanism achieves rapid switching of the hydraulic control valve's oil circuit, improving switching efficiency and significantly shortening the mechanism's start-up time. After the electromagnetic repulsion mechanism completes the control valve's oil circuit switching, the remaining energy and kinetic energy, combined with the piston rod of the working cylinder, continue to drive the arc-extinguishing chamber contacts to separate, greatly increasing the acceleration in the initial stage of opening, improving the contact separation speed, and shortening the opening time. After the electromagnetic repulsion mechanism operates, it uses the piston rod and arc-extinguishing chamber transmission to decelerate and buffer the metal disc, omitting the buffer structure. The energy is used for arc-extinguishing chamber opening, improving energy utilization efficiency. The invention achieves the organic integration of the electromagnetic repulsion mechanism and the working cylinder, providing a new solution for further shortening the opening time of ultra-high voltage fast circuit breakers. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 A cross-sectional view of the closing position transmission mechanism provided by the present invention; Figure 2 A cross-sectional view of the electromagnetic repulsion mechanism at the closing position provided by the present invention; Figure 3 A cross-sectional view of the hydraulic control valve for the closing position provided by the present invention; Figure 4 This is a cross-sectional view of the tripping position transmission mechanism provided by the present invention; Figure 5 This is a cross-sectional view of the electromagnetic repulsion mechanism for the opening position provided by the present invention; Figure 6 This is a cross-sectional view of the hydraulic control valve for the tripping position provided by the present invention.

[0021] Among them, 1-working cylinder; 11-cylinder body; 12-piston rod; 13-working flow channel; 2-hydraulic control valve; 21-valve body; 22-normal low-pressure oil chamber; 23-working oil chamber; 24-normal high-pressure oil chamber; 25-valve rod; 26-connecting flow channel; 27-upper valve sleeve; 28-lower valve sleeve; 29-valve core; 3-electromagnetic repulsion mechanism; 31-base; 32-repulsion coil; 33-metal disc; 34-push rod; 4-push plate; 5-control circuit; 51-switch; 52-capacitor. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 like Figure 1 and 4 As shown, a repulsive force and hydraulic graded drive transmission mechanism according to an embodiment of the present invention includes a working cylinder 1, a hydraulic control valve 2, and an electromagnetic repulsive force mechanism 3; the hydraulic control valve 2 and the electromagnetic repulsive force mechanism 3 are each provided in two sets and symmetrically arranged at the upper end of the cylinder body 11; the working cylinder 1 includes a cylinder body 11 and a piston rod 12, and a working flow channel 13 is opened on the cylinder body 11; the piston rod 12 is slidably connected in the oil chamber of the cylinder body 11; as shown Figure 3 and 6 As shown, the hydraulic control valve 2 includes a valve body 21 and a valve core 29; the valve body 21 is bolted to the upper end of the cylinder body 11; the valve body 21 has a constant low-pressure oil chamber 22, a working oil chamber 23, and a constant high-pressure oil chamber 24 arranged sequentially from top to bottom; the working flow channel 13 connects the working oil chamber 23 and the oil chamber of the cylinder body 11; the working oil chamber 23 is connected to the lower part of the working cylinder 1 oil chamber through an oil circuit to hydraulically drive the piston rod 12; the valve core 29 is located in the working oil chamber 23 and can slide up and down to control the connection and disconnection between the working oil chamber 23 and the constant low-pressure oil chamber 22 and the constant high-pressure oil chamber 24; Figure 2 and 5As shown, the electromagnetic repulsion mechanism 3 includes a base 31, a push rod 34, and a repulsion coil 32. The base 31 is fixed to the upper end of the valve body 21. The push rod 34 is slidably connected to the base 31, and its lower end is fixed to the valve core 29, while its upper end is connected to the upper end of the piston rod 12 via a connector. The repulsion coil 32 is fixed to the top surface of the base 31 and, when energized, generates electromagnetic repulsion between itself and the push rod 34. Both the hydraulic control valve 2 and the electromagnetic repulsion mechanism 3 are provided in two sets, symmetrically arranged at the upper end of the cylinder body 11.

[0024] In this embodiment, the connecting member is a push plate 4. One end of the push plate 4 is fixed to the upper outer wall of the piston rod 12, and the plate surface of the other end is sleeved on the top rod 34. The electromagnetic repulsion mechanism 3 also includes a metal disk 33, which is fixed to the upper end of the top rod 34. After the repulsion coil 32 is energized, it can generate electromagnetic repulsion between itself and the metal disk 33. The push plate 4 is located below the metal disk 33. The end of the push plate 4 away from the piston rod 12 has a through hole and is sleeved on the top rod 34. The inner wall of the through hole slides against the outer wall of the top rod 34.

[0025] The connection between the working oil chamber and the constant pressure oil chamber can be achieved by using an annular groove as in existing technologies or by opening a connecting hole on the valve body. The specific connection method will not be described in detail here.

[0026] In this embodiment, the constant high-pressure oil chamber is connected to the accumulator in the hydraulic system, and the constant low-pressure oil chamber is connected to the oil tank in the hydraulic system. Figure 1 As shown, when the repulsion coil is not energized, the working oil chamber is connected to the constant high-pressure oil chamber. The accumulator stores energy to ensure that the constant high-pressure oil chamber is always filled with high-pressure oil. The high-pressure oil in the constant high-pressure oil chamber enters the lower part of the cylinder oil chamber through the working oil chamber. The high-pressure oil fills the cylinder oil chamber from the lower part to balance the oil pressure. The cross-sectional area of ​​the lower part of the oil chamber is larger than that of the upper part of the oil chamber, so the piston rod will not move down.

[0027] When the repulsion coil is energized, it enables the hydraulic control valve to switch oil circuits. Specifically, the electromagnetic repulsion pushes the metal disc downward, which in turn moves the push rod downward. At the same time, the metal disc presses down on the push plate, causing the piston rod to move downward synchronously. During the downward movement of the push rod and push plate, the valve core closes the connection channel between the working oil chamber and the constant high-pressure oil chamber, while simultaneously connecting the working oil chamber with the constant low-pressure oil chamber. The low-pressure oil in the constant low-pressure oil chamber fills in from the lower part of the cylinder oil chamber, creating an oil pressure difference between the upper and lower parts of the cylinder oil chamber, which in turn causes the piston rod to move downward.

[0028] In some other specific embodiments, an oil separator ring is fixed on the piston rod. The circumferential surface of the oil separator ring slides against the inner wall of the cylinder. The oil separator ring divides the oil chamber of the cylinder into an upper oil chamber and a lower oil chamber. The upper oil chamber is always filled with high-pressure oil, and the lower oil chamber is connected to the working oil chamber. The movement of the piston rod is achieved by changing the properties of the hydraulic oil in the lower oil chamber.

[0029] To further optimize the above technical solution, the hydraulic control valve 2 also includes a valve stem 25, which is slidably connected within the valve body 21; a valve core 29 is fixed on the valve stem 25; and a push rod 34 is coaxially arranged with the valve stem 25, with its lower end fixed to the upper end of the valve stem 25. The valve core is connected to the push rod via the valve stem, and the movement of the push rod causes the valve stem and valve core to move as a whole.

[0030] In this embodiment, an upper valve sleeve 27 and a lower valve sleeve 28 are also included. The upper valve sleeve 27 is fixed to the upper inner wall of the valve body 21, and its inner cavity forms a constant low-pressure oil chamber 22. The lower valve sleeve 28 is fixed to the lower inner wall of the valve body 21, and its inner cavity forms a constant high-pressure oil chamber 24. The lower end face of the upper valve sleeve 27, the upper end face of the lower valve sleeve 28, and the inner wall of the valve body 21 together form a working oil chamber 23. The circumferential surface and the vertical sliding surface of the valve core 29 form a sealing surface with the bottom surface of the upper valve sleeve 27 or the top surface of the lower valve sleeve 28.

[0031] like Figure 3 and 6 As shown, the valve core, along with the upper valve sleeve, lower valve sleeve, and valve body, forms a low-pressure oil chamber, a working oil chamber, and a high-pressure oil chamber. When the repulsion coil is not energized, the piston rod does not move. The valve core is pressed tightly against the bottom surface of the upper valve sleeve and the top surface of the lower valve sleeve to form a sealing surface, sealing the low-pressure oil chamber and the working oil chamber. At this time, the working oil chamber is connected to the high-pressure oil chamber. When the valve core moves downward into the lower valve sleeve, it closes the connection channel between the high-pressure oil chamber and the working oil chamber, and at this time, the low-pressure oil chamber is connected to the working oil chamber.

[0032] To further optimize the above technical solution and prevent axial leakage of hydraulic oil in the working oil chamber, annular grooves are provided on the outer walls of the upper and lower ends of the valve core.

[0033] To further optimize the above technical solution, a connecting flow channel 26 is provided on the valve body 21; there is a moving gap between the lower end of the valve stem 25 and the inner bottom wall of the valve body 21; the connecting flow channel 26 connects the working oil chamber 23 and the moving gap.

[0034] Once the push rod has reached its stroke position, high-pressure oil enters the moving gap through the connecting channel, and the high-pressure oil within the moving gap resets the push rod. Meanwhile, low-pressure oil flows slowly within the cylinder, maintaining a continuous oil pressure difference. This means that once the push rod is in position, the piston rod will continue to move downwards under the influence of the oil pressure difference, achieving staged drive. The push rod's reset is achieved via a hydraulic control valve; the electromagnetic repulsion mechanism does not participate in the push rod reset.

[0035] In other specific embodiments, such as Figure 2 and 5 As shown, the opening and closing of the repulsion coil is achieved through the control circuit 5, which is electrically connected to the repulsion coil 32. The control circuit 5 is equipped with a switch 51 and a capacitor 52. When the switch 51 is closed, the capacitor 52 discharges to the repulsion coil 32.

[0036] Example 2 According to an embodiment of the present invention, a circuit breaker is provided, which adopts a repulsive force and hydraulic graded drive transmission mechanism as described in Embodiment 1, wherein the upper end of the piston rod 12 can abut against the contacts in the arc-extinguishing chamber. The repulsion coil 32 is not energized, the working oil chamber 23 is connected to the constant high pressure oil chamber 24, the oil chamber of the working cylinder 1 is filled with high pressure oil, the upper end of the piston rod 12 is in contact with the contact, and the circuit breaker is in the closed position. When the repulsion coil 32 is energized, it pushes the valve core 29 to move down, so that the working oil chamber 23 is connected to the normal low-pressure oil chamber 22. In this state, the low-pressure oil will enter the lower part of the working cylinder 1 oil chamber, so that there is an oil pressure difference in the working cylinder 1 oil chamber. During the process of the valve core 29 moving down, the piston rod 12 is driven to move down through the oil pressure difference, so that the piston rod 12 is separated from the contact, and the circuit breaker is in the open position.

[0037] See appendix Figure 1 and 4 The piston rod is detachably connected to a clamp at its upper end. A control component is included, which extends into the arc-extinguishing chamber and contacts the contacts. The outer wall of the clamp is fixed to the side end face of the push plate. In the closed position, the working oil chamber is connected to the normal high-pressure oil chamber, the piston rod does not move, and the control component contacts the contacts to achieve closing. After receiving the tripping command, the control circuit triggers the switch to close, the capacitor discharges to the repulsion coil, the metal disc moves, driving the push rod to move the valve stem and valve core. After the valve core moves, the hydraulic control valve oil circuit is switched, and the working oil chamber is connected to the constant low-pressure oil chamber. The hydraulic oil in the working oil chamber changes from high-pressure oil to low-pressure oil, causing the lower part of the cylinder to change from high-pressure oil to low-pressure oil, while the upper part of the cylinder remains high-pressure oil. Under the pressure difference, the piston rod moves to the tripping position. The metal disc continues to move, contacting the push plate connected to the clamp. The metal disc applies a symmetrical thrust in the tripping direction to the push plate. This thrust and the piston rod's tripping force are in the same direction, jointly driving the arc-extinguishing chamber contacts to separate. After reaching a certain stroke, the metal disc stops moving, and the piston rod continues to drive the arc-extinguishing chamber to complete the tripping operation. After the metal disc and push rod have completed their movements, the push rod returns to its initial position and remains there under the high oil pressure in the hydraulic control valve. During the closing operation, the hydraulic mechanism completes the operation independently, and the repulsion mechanism does not participate.

[0038] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transmission mechanism driven by repulsive force and hydraulic cascading, characterized in that, include: Working cylinder (1) A hydraulic control valve (2) includes a valve body (21) and a valve core (29); the valve body (21) is bolted to the upper end of the working cylinder (1); the valve body (21) is provided with a constant low-pressure oil chamber (22), a working oil chamber (23) and a constant high-pressure oil chamber (24) from top to bottom; the working oil chamber (23) is connected to the lower part of the working cylinder (1) through an oil circuit to hydraulically drive the piston rod (12); the valve core (29) is located in the working oil chamber (23) and can slide up and down to control the connection and disconnection between the working oil chamber (23) and the constant low-pressure oil chamber (22) and the constant high-pressure oil chamber (24); The electromagnetic repulsion mechanism (3) includes a base (31), a push rod (34), and a repulsion coil (32). The base (31) is fixed to the upper end of the valve body (21). The push rod (34) is slidably connected to the base (31) and its lower end is fixed to the valve core (29). Its upper end is connected to the upper end of the piston rod (12) of the working cylinder (1) through a connector. The repulsion coil (32) is fixed to the top surface of the base (31) and can generate electromagnetic repulsion between itself and the push rod (34) after being energized.

2. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 1, characterized in that, The connecting component is a push plate (4). One side of the push plate (4) is fixed to the upper outer wall of the piston rod (12), and the plate surface of the other end is sleeved on the top rod (34).

3. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 2, characterized in that, The electromagnetic repulsion mechanism (3) also includes a metal disk (33), which is fixed to the upper end of the push rod (34). When the repulsion coil (32) is energized, it can generate electromagnetic repulsion between itself and the metal disk (33). The push plate (4) is located below the metal disk (33). The push plate (4) has a through hole at one end away from the piston rod (12) and is sleeved on the push rod (34). The inner wall of the through hole slides against the outer wall of the push rod (34).

4. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 1, characterized in that, The hydraulic control valve (2) also includes a valve stem (25), which is slidably connected inside the valve body (21); the valve core (29) is fixed on the valve stem (25); the push rod (34) is coaxially arranged with the valve stem (25) and the lower end of the push rod (34) is fixed to the upper end of the valve stem (25).

5. The transmission mechanism for repulsive force and hydraulic graded drive according to claim 4, characterized in that, It also includes an upper valve sleeve (27) and a lower valve sleeve (28); the upper valve sleeve (27) is fixed to the upper inner wall of the valve body (21), and its inner cavity forms the normal low-pressure oil chamber (22); the lower valve sleeve (28) is fixed to the lower inner wall of the valve body (21), and its inner cavity forms the normal high-pressure oil chamber (24); the lower end face of the upper valve sleeve (27), the upper end face of the lower valve sleeve (28) and the inner wall of the valve body (21) together form the working oil chamber (23), and the circumferential surface and the sliding surface of the valve core (29) form a sealing surface with the bottom surface of the upper valve sleeve (27) or the top surface of the lower valve sleeve (28).

6. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 5, characterized in that, The valve body (21) is provided with a connecting flow channel (26); there is a moving gap between the lower end of the valve stem (25) and the inner bottom wall of the valve body (21); the connecting flow channel (26) connects the working oil chamber (23) and the moving gap.

7. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 1, characterized in that, It also includes a control circuit (5), which is electrically connected to the repulsion coil (32); the control circuit (5) is provided with a switch (51) and a capacitor (52); the switch (51) is closed so that the capacitor (52) discharges to the repulsion coil (32).

8. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 1, characterized in that, The working cylinder (1) includes a cylinder body (11) and a working flow channel (13) is provided on the cylinder body (11); the piston rod (12) is slidably connected in the oil chamber of the cylinder body (11); the working flow channel (13) connects the working oil chamber (23) and the oil chamber of the cylinder body (11).

9. The transmission mechanism of repulsive force and hydraulic graded drive according to claim 8, characterized in that, The hydraulic control valve (2) and the electromagnetic repulsion mechanism (3) are both provided in two sets and symmetrically arranged at the upper end of the cylinder (11).

10. A circuit breaker, characterized in that, The transmission mechanism includes a repulsive force and hydraulic graded drive as described in any one of claims 1 to 9, wherein the upper end of the piston rod (12) can abut against the contacts in the arc-extinguishing chamber; The repulsion coil (32) is not energized, the working oil chamber (23) is connected to the constant high pressure oil chamber (24), the oil chamber of the working cylinder (1) contains high pressure oil, the upper end of the piston rod (12) abuts against the contact, and the circuit breaker is in the closed position. After the repulsion coil (32) is energized, it pushes the valve core (29) to move down, so that the working oil chamber (23) is connected to the constant low pressure oil chamber (22), so that there is an oil pressure difference in the oil chamber of the working cylinder (1). During the process of the valve core (29) moving down, the piston rod (12) is driven to move down through the oil pressure difference, so that the piston rod (12) is separated from the contact, and the circuit breaker is in the open position.

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