Balance valve, method and motor

Abstract

According to the balance valve, the method and the motor, in the oil discharge process of a control cavity, when a balance valve element moves, variable damping is formed by the balance valve element and an oil return channel arranged on the stroke of the valve element, fixed damping is arranged on a one-way throttling valve element, and the variable damping and the fixed damping are combined to form a balance valve speed control damping network; the reset process of the balance valve element is divided into two stages which are fast first and slow second, and meanwhile the requirements for fast response and impact prevention of the reversing action of the motor are met. According to the balance valve, the method and the motor, load equipment can be effectively protected, and the control precision of a system is improved.

Description

Technical Field

[0001] The invention relates to a balancing valve, a method and a motor, and belongs to the technical field of engineering machinery. Background Art

[0002] Crawler cranes, crawler excavators and other construction machinery travel drives are swash plate axial piston motors. In the travel motor system of construction machinery, the balance valve plays an important role in controlling the sequence of motor rotation, stopping and mechanical braking, preventing the motor from overspeeding and stalling, and controlling the smooth start and stop of the excavator.

[0003] The reversing speed of the balance valve core during the opening and resetting process affects the performance of the action response speed and impact size during the motor starting and braking process, and also has a significant impact on the operating comfort and reliability of the equipment during the walking and parking process. During the equipment starting process, on the one hand, the equipment needs to respond quickly to avoid the return oil port opening too slowly, causing the motor to be pressurized, and the internal pressure drops rapidly after the return oil port is opened. On the other hand, it is necessary to avoid the collision and shock between the balance valve and the limit structure after reaching the maximum stroke. Therefore, the motor starting process requires the balance valve to open quickly and smoothly; during the equipment parking process, the equipment also needs to respond quickly so that the equipment can quickly enter the braking stage after receiving the parking command; after entering the braking stage, it is necessary to avoid the return oil port closing too quickly, the rotating parts continue to rotate under the action of inertia, resulting in the inertial impact of the motor return oil chamber being pressurized, and the motor reversal caused by excessive pressure. Therefore, the balance valve needs to be reset in two stages when parking, first fast and then slow.

[0004] Since the motor needs to operate in both directions, when oil is fed from port A, the damping on the oil inlet side during the start-up phase will become the damping on the oil return side during the reset phase. In order to ensure the consistency of the equipment's operation when oil is fed from ports A and B, the damping holes of the left and right control chambers must be the same size. Therefore, when adjusting the diameter of the damping hole, the opening and reset speeds of the balancing valve will increase or decrease at the same time, and the fast action response and small impact will show a trend of large to small, which cannot take into account the requirements of fast action response and small impact at the same time. Moreover, the moving speed of the balancing valve is only adjusted through the damping hole, and it is impossible to achieve the two stages of fast first and slow later when the equipment is stopped.

[0005] Under the existing structure, when the aperture of the damping holes of the left and right control chambers changes, the opening speed and reset speed of the balancing valve core will increase or decrease at the same time. Therefore, it is impossible to take into account the requirements of fast response of the switching action and shock protection at the same time, which greatly limits the control accuracy and adjustability of the equipment. Summary of the invention

[0006] Purpose: To overcome the deficiencies in the prior art, the present invention provides a balancing valve, method and motor.

[0007] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is:

[0008] In a first aspect, a balancing valve comprises: a main valve body, a balancing valve core, wherein the balancing valve core comprises: a left chamber and a right chamber. The main valve body is provided with oil port A, an oil port of chamber A, and oil port B, an oil port of chamber B, respectively. A through hole is provided on the left chamber, and the through hole is used to communicate with oil port A and the oil port of chamber A. A through hole is provided on the right chamber, and the through hole is used to communicate with oil port B and the oil port of chamber B.

[0009] The main valve body is also provided with a first transverse oil passage and a second transverse oil passage respectively.

[0010] The first transverse oil passage is respectively longitudinally penetrated by a first oil passage a, a second oil passage a and a third oil passage a. An oil passage plug is provided at one end of the first oil passage a, and the other end of the first oil passage a is communicated with the control cavity of the balancing valve spring on the left side. An oil passage plug is provided at one end of the second oil passage a. When the balancing valve core 1 is in the middle position and the left position, the other end of the second oil passage a is cut off by the balancing valve core. When the balancing valve core moves to the right from a distance of m to a distance of m+n, the other end of the second oil passage a and the control cavity of the balancing valve spring on the left side are in a gradually conducting state. An oil passage plug is provided at one end of the third oil passage a, and the other end of the third oil passage a is communicated with the oil port A. A first one-way throttling valve core is provided on the first transverse oil passage at the intersection of the first transverse oil passage and the first oil passage a, a first one-way throttling valve core spring is provided at the rear end of the first one-way throttling valve core, and a first screw plug is provided at the rear end of the first one-way throttling valve core spring.

[0011] The second transverse oil passage is respectively longitudinally penetrated by a first oil passage b, a second oil passage b and a third oil passage b, an oil passage plug is provided at one end of the first oil passage b, and the other end of the first oil passage b is communicated with the control chamber of the balancing valve spring on the right side, an oil passage plug is provided at one end of the second oil passage b, when the balancing valve core is in the middle position and the right position, the other end of the second oil passage b is cut off by the balancing valve core, when the balancing valve core moves to the left from a distance m to a distance m+n, the other end of the second oil passage b is in a gradually connected state with the control chamber of the balancing valve spring on the right side, an oil passage plug is provided at one end of the third oil passage b, and the other end of the third oil passage b is communicated with the oil port B, a second one-way throttling valve core is provided on the second transverse oil passage at the intersection of the second transverse oil passage and the first oil passage b, a second one-way throttling valve core spring is provided at the rear end of the second one-way throttling valve core, and a second screw plug is provided at the rear end of the second one-way throttling valve core spring.

[0012] The inlet of the first one-way throttle valve core and the second one-way throttle valve core is provided with a first damping hole, and the side wall is provided with a second damping hole.

[0013] As a preferred solution, a third damping hole is provided in the second oil passage a.

[0014] As a preferred solution, a third damping hole is provided in the second oil passage b.

[0015] As a preferred solution, the larger the diameter of the first damping hole is, the faster the moving speed of the balancing valve core is, and the faster the action response speed of the motor is.

[0016] As a preferred solution, the larger the diameter of the second damping hole is, the faster the moving speed of the balancing valve core is, and the faster the action response speed of the motor is.

[0017] As a preferred solution, when the balancing valve core is in the middle position, the smaller the distance m between the end face of the balancing valve core and one side of the second oil passage a is, the earlier the balancing valve core can close the second oil passage a during the resetting process.

[0018] As a preferred solution, when the balancing valve core is in the middle position, the smaller the distance m between the end face of the balancing valve core and one side of the second oil passage b is, the earlier the balancing valve core closes the second oil passage b during the resetting process.

[0019] In a second aspect, a working method of a balancing valve specifically includes:

[0020] When the high-pressure oil enters the oil port A of the balancing valve, it pushes the one-way valve core in the left chamber to move to the left, and the high-pressure oil flows from the connected oil port of the A chamber into the A port of the motor, pushing the motor to rotate the parts. At this time, the oil port B of the balancing valve is closed, and the return oil from the B port of the motor cannot flow out of the balancing valve; at the same time, the high-pressure oil enters the first lateral oil channel through the third oil channel a. Since the second oil channel a is cut off by the balancing valve core, the high-pressure oil reaches the first one-way throttle valve core, overcomes the preload spring force of the first one-way throttle valve core, opens the first one-way throttle valve core, and enters the control chamber of the balancing valve spring on the left through the first oil channel a. After the pressure in the control chamber is increased, the balancing valve core is pushed to move to the right. The balancing valve core moving to the right pushes the oil in the control chamber of the balancing valve spring on the right side through the first oil channel b to the second one-way throttle valve core. At this time, the second one-way throttle valve core is cut off and the second oil channel b is cut off. The oil flows out through the second damping hole and the first damping hole on the second one-way throttle valve core, through the second one-way throttle valve core, and enters the oil port B through the third oil channel b, and flows out from the oil port B. The oil port B of the balancing valve is slowly connected with the oil port of the B chamber, the second oil channel a is gradually connected, and the return oil of the B port of the motor flows out from the slowly connected oil port B, so as to realize the smooth start of the motor.

[0021] When the high-pressure oil supply to the oil port A of the balancing valve stops, the motor rotating parts continue to rotate under the action of inertia, and the oil port B still has the return oil from the motor B port flowing out. The balancing valve core is reset to the left under the spring force of the balancing valve spring on the right, and negative pressure is generated in the control chamber of the balancing valve spring on the right. The second one-way throttle valve core opens and the second oil channel b is cut off, and the oil flows into the control chamber on the right through the first oil channel b for oil replenishment. At the same time, the first one-way throttle valve core is cut off, and the oil in the control chamber of the balancing valve spring on the left flows out from the first oil channel a through the second damping hole on the first one-way throttle valve core, the first damping hole and the second oil channel a to the oil port of the A chamber, until the left-moving balancing valve core gradually closes the second oil channel a, and the balancing valve core returns to the middle position.

[0022] As a preferred solution, when the balancing valve core moves to the left to the range of (s0-mn)≤s≤(s0-m), the second oil channel a is gradually closed, and the oil in the left control chamber returns to the oil port of chamber A through the damping hole of the first one-way throttle valve core on the first oil channel a and the second oil channel a for discharge. Under the joint regulation of the variable damping formed by the first oil channel a and the second oil channel a and the fixed damping on the one-way throttle valve, the resetting speed of the balancing valve core is gradually reduced.

[0023] When the balancing valve core moves to the left to the range of s≤(s0-mn), the second oil channel a is completely closed, and the oil in the left control chamber passes through the first oil channel a and reaches the first one-way throttle valve core. At this time, the hydraulic pressure acting on the first one-way throttle valve core is not enough to overcome the preload spring force. The oil passes through the second damping hole and the first damping hole on the first one-way throttle valve core, passes through the first one-way throttle valve core, and then returns to the oil port of the A chamber through the first oil channel a for discharge. The balancing valve core is reset slowly, the oil port B is gradually closed, and the motor is gradually stopped. Among them, s0 is the total displacement distance of the balancing valve core, m is the distance between the end face of the balancing valve core and the second oil channel a or the second oil channel b when the balancing valve core is in the middle position, n is the groove width of the second oil channel a or the second oil channel b, and s is the moving distance of the balancing valve core.

[0024] A third aspect provides a motor, comprising the balancing valve described in the first aspect.

[0025] Beneficial effects: The present invention provides a balancing valve, method and motor. During the process of oil discharge from a control chamber, the balancing valve core forms variable damping with the return oil channel arranged on the valve core stroke when the balancing valve core moves. The fixed damping is arranged on the one-way throttling valve core. The variable damping and the fixed damping are combined to form a balancing valve speed control damping network, which divides the resetting process of the balancing valve core into two stages, first fast and then slow. At the same time, the requirements of fast response of the switching action and shock protection are taken into account, which can effectively protect the load equipment and improve the control accuracy of the system.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The speed control circuit designed in the present invention is composed of a variable damping and a fixed damping hole, wherein the variable damping is composed of a balancing valve core and an oil channel arranged on the balancing valve core stroke, and the fixed damping is arranged on the one-way throttle valve, which has the advantages of simple structure, easy layout, disassembly and maintenance.

[0028] 2. The speed control circuit designed in the present invention can divide the resetting process of the balancing valve core into two stages: fast first and slow later, reducing the correlation between the opening and resetting actions of the balancing valve core, while taking into account the requirements of fast action response and impact protection, which can effectively protect the load equipment, improve the control accuracy of the system, and enhance the comfort of motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the balancing valve of the present invention.

[0030] Figure 2 It is a structural schematic diagram of a one-way throttling valve core.

[0031] Figure 3 It is a hydraulic principle diagram of the control circuit of the balancing valve of the present invention.

[0032] Figure 4 It is a schematic diagram of the displacement characteristics of the balancing valve of the present invention. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the examples of the present invention in conjunction with the accompanying drawings in the examples of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present invention.

[0034] The present invention will be further described below in conjunction with specific embodiments.

[0035] Embodiment 1:

[0036] This embodiment introduces a balancing valve. Figure 1 As shown, it includes: a main valve body 12, a balancing valve core 1, a balancing valve core 1 is movably arranged in the main valve body 12, and a one-way valve core 2, a one-way valve spring 3, a spring gasket 4, a balancing valve screw plug 5, a balancing valve spring 6, and a balancing valve end cover 7 are symmetrically arranged on the left and right sides of the balancing valve core 1.

[0037] The balancing valve screw plug 5 is connected to the inner wall of the balancing valve core 1, and a one-way valve spring 3 is arranged at one end of the balancing valve screw plug 5, and a one-way valve core 2 is arranged on the one-way valve spring 3. The left and right ends of the main valve body 12 are both provided with balancing valve end covers 7, and a balancing valve spring 6 is arranged in the balancing valve end cover 7. The free end of the balancing valve spring 6 is provided with a spring gasket 4, and the front end of the spring gasket 4 is connected to the end surface of the balancing valve core 1.

[0038] The balancing valve core 1 includes a left chamber 101 and a right chamber 102. The main valve body 12 is provided with oil port A8, oil port 9 of chamber A, oil port B10, and oil port 11 of chamber B. A through hole is provided on the left chamber 101, and the through hole is used to communicate with the oil port A8 and the oil port 9 of chamber A. A through hole is provided on the right chamber 102, and the through hole is used to communicate with the oil port B10 and the oil port 11 of chamber B.

[0039] The main valve body 12 is also provided with a first transverse oil passage 13 and a second transverse oil passage 14 .

[0040] The first transverse oil passage 13 is respectively longitudinally penetrated by a first oil passage a15, a second oil passage a16, and a third oil passage a17. An oil passage plug 18 is provided at one end of the first oil passage a15. The other end of the first oil passage a15 is communicated with the control cavity of the balance valve spring 6 on the left. An oil passage plug 18 is provided at one end of the second oil passage a16. When the balance valve core 1 is in the middle position, the left position, the other end of the second oil passage a16 is blocked by the balance valve core 1. When the balance valve core 1 moves to the right from a distance m to a distance m+n, the second oil passage a16 is blocked. The other end of a16 is in a gradually connected state with the control cavity of the balancing valve spring 6 on the left side, an oil channel plug is provided at one end of the third oil channel a17, and the other end of the third oil channel a17 is connected with the oil port A8, and a first one-way throttle valve core 19 is provided on the first transverse oil channel 13 at the intersection of the first transverse oil channel 13 and the first oil channel a15, and a first one-way throttle valve core spring 20 is provided at the rear end of the first one-way throttle valve core 19, and a first screw plug 21 is provided at the rear end of the first one-way throttle valve core spring 20.

[0041] The second transverse oil passage 14 is respectively longitudinally penetrated by a first oil passage b22, a second oil passage b23, and a third oil passage b24. An oil passage plug 18 is provided at one end of the first oil passage b22. The other end of the first oil passage b22 is communicated with the control cavity of the balancing valve spring 6 on the right side. An oil passage plug 18 is provided at one end of the second oil passage b23. When the balancing valve core 1 is in the middle position, the right position, the other end of the second oil passage b23 is blocked by the balancing valve core 1. When the balancing valve core 1 moves to the left from a distance m to a distance m+n, the second oil passage b The other end of the third oil passage b23 is in a gradually connected state with the control cavity of the balance valve spring 6 on the right side, an oil passage plug 18 is provided at one end of the third oil passage b24, and the other end of the third oil passage b24 is connected with the oil port B10, and a second one-way throttle valve core 25 is provided on the second transverse oil passage 14 at the intersection of the second transverse oil passage 14 and the first oil passage b22, a second one-way throttle valve core spring 26 is provided at the rear end of the second one-way throttle valve core 25, and a second screw plug 27 is provided at the rear end of the second one-way throttle valve core spring 26.

[0042] like Figure 2 As shown, the first one-way throttle valve core 19 and the second one-way throttle valve core 25 are provided with a first damping hole 28 at the inlet, and a second damping hole 29 on the side wall. When the oil port A8 or the oil port B10 is a high-pressure oil port, the high-pressure oil will act on the one-way throttle valve core to overcome the spring force, open the one-way throttle valve core and enter the control cavity where the balance valve spring is located; when the control cavity is discharged through the one-way throttle valve core, the oil in the control cavity passes through the first oil channel a or the first oil channel b, the second damping hole, the first damping hole, and then enters the third oil channel a or the third oil channel b, and returns to the oil port A8 or the oil port B10 low-pressure oil port for discharge.

[0043] Furthermore, a third damping hole 30 is provided in the second oil passage a for controlling the reflux speed of the oil in the control cavity of the left balancing valve spring 6 .

[0044] Furthermore, a third damping hole 30 is provided in the second oil passage b, which is used to control the reflux speed of the oil in the control cavity of the right balancing valve spring 6 .

[0045] Furthermore, the larger the diameter of the first damping hole 28 and / or the second damping hole 29 is, the faster the moving speed of the balancing valve core is, and the faster the action response speed of the motor is.

[0046] Furthermore, the smaller the moving distance m of the balancing valve core 1 is, the earlier the balancing valve core closes the second oil channel a or the second oil channel b during the resetting process, shortening the rapid resetting phase of the balancing valve core and extending the slow resetting phase, allowing the motor to enter the braking phase earlier and the braking process to be smoother.

[0047] Embodiment 2:

[0048] This embodiment introduces a working method of a balancing valve. Figure 3 As shown, specifically including:

[0049] When the high-pressure oil enters the oil port A of the balancing valve, it pushes the one-way valve core in the left chamber to move to the left, and the high-pressure oil flows from the connected oil port of the A chamber into the A port of the motor, pushing the motor to rotate the parts. At this time, the oil port B of the balancing valve is closed, and the return oil from the B port of the motor cannot flow out of the balancing valve; at the same time, the high-pressure oil enters the first lateral oil channel through the third oil channel a. Since the second oil channel a is cut off by the balancing valve core, the high-pressure oil reaches the first one-way throttle valve core, overcomes the preload spring force of the first one-way throttle valve core, opens the first one-way throttle valve core, and enters the control chamber of the balancing valve spring on the left through the first oil channel a. After the pressure in the control chamber is increased, the balancing valve core is pushed to move to the right. The balancing valve core moving to the right pushes the oil in the control chamber of the balancing valve spring on the right side through the first oil channel b to the second one-way throttle valve core. At this time, the second one-way throttle valve core is cut off and the second oil channel b is cut off. The oil flows out through the second damping hole and the first damping hole on the second one-way throttle valve core, through the second one-way throttle valve core, and enters the oil port B through the third oil channel b, and flows out from the oil port B. The oil port B of the balancing valve is slowly connected with the oil port of the B chamber, the second oil channel a is gradually connected, and the return oil of the B port of the motor flows out from the slowly connected oil port B, so as to realize the smooth start of the motor.

[0050] When the high-pressure oil supply to the oil port A of the balancing valve stops, the motor rotating parts continue to rotate under the action of inertia, and the oil port B still has the return oil from the motor B port flowing out. The balancing valve core is reset to the left under the spring force of the balancing valve spring on the right, and negative pressure is generated in the control chamber of the balancing valve spring on the right. The second one-way throttle valve core opens and the second oil channel b is cut off, and the oil flows into the control chamber on the right through the first oil channel b for oil replenishment. At the same time, the first one-way throttle valve core is cut off, and the oil in the control chamber of the balancing valve spring on the left flows out from the first oil channel a through the second damping hole on the first one-way throttle valve core, the first damping hole and the second oil channel a to the oil port of the A chamber, until the left-moving balancing valve core gradually closes the second oil channel a, and the balancing valve core returns to the middle position.

[0051] Furthermore, when the balancing valve core moves to the left to the range of (s0-mn)≤s≤(s0-m), the second oil channel a gradually closes, and the oil in the left control chamber returns to the oil port of chamber A through the damping hole of the first one-way throttling valve core on the first oil channel a and the second oil channel a for discharge. Under the joint regulation of the variable damping formed by the first oil channel a and the second oil channel a and the fixed damping on the one-way throttle valve, the resetting speed of the balancing valve core gradually decreases.

[0052] When the balancing valve core moves to the left to the range of s≤(s0-mn), the second oil channel a is completely closed, and the oil in the left control chamber passes through the first oil channel a and reaches the first one-way throttle valve core. At this time, the hydraulic pressure acting on the first one-way throttle valve core is not enough to overcome the preload spring force. The oil passes through the second damping hole and the first damping hole on the first one-way throttle valve core, passes through the first one-way throttle valve core, and then returns to the oil port of the A chamber through the first oil channel a for discharge. The balancing valve core is reset slowly, the oil port B is gradually closed, and the motor is gradually stopped. Among them, s0 is the total displacement distance of the balancing valve core, m is the distance between the end face of the balancing valve core and the second oil channel a or the second oil channel b when the balancing valve core is in the middle position, n is the groove width of the second oil channel a or the second oil channel b, and s is the moving distance of the balancing valve core.

[0053] The oil in the left control chamber first passes through the first damping hole on the first oil channel a, and then quickly returns to the oil port of chamber A through the second damping hole and the second oil channel a, and is discharged from the A port of the motor. The balancing valve core quickly moves to the left and resets. During this stage, the oil port B is still in the open state. After this stage, the balancing valve slowly resets and the motor enters the braking stage.

[0054] The above process explains:

[0055] During the motor starting process, when the motor starts to work at a speed only through the oil return from the right control chamber, the first damping hole and the second damping hole arranged on the second one-way throttle valve core perform speed matching.

[0056] During the motor stop process, the resetting of the balancing valve is successively speed-adjusted by the second oil channel a, the first damping hole arranged on the first one-way throttle valve core, and the second damping hole. Therefore, the correlation between the opening and resetting actions of the balancing valve core can be reduced, taking into account the requirements of fast motor action response and impact protection.

[0057] Adjustment of the displacement characteristics of the balancing valve core Figure 4 As shown, the solid line in the figure is before adjustment, and the dotted line is after adjustment. When the motor needs to be adjusted to achieve faster action response speed and smaller impact, the existing structure can only achieve one by adjusting the diameter of the throttle plug and sacrifice the other requirement, while the structure of the present invention can achieve both in the following ways: increase the diameter of the first damping hole and the second damping hole on the one-way throttle valve core, thereby reducing the damping effect of the return oil side damping when the balance valve core is opened during the motor startup process, so that the balance valve core moves faster and the motor action response speed is faster; reduce the layout size of the second oil channel a and the second oil channel b from m to m', so that the balance valve core closes the second oil channel a or the second oil channel b earlier in the reset process, shortens the fast reset stage of the balance valve core, and prolongs the slow reset stage, so that the motor enters the braking stage earlier, and the braking process is smoother, achieving faster action response and smaller impact during the parking process.

[0058] Embodiment 3:

[0059] This embodiment introduces a motor, which includes the balancing valve described in Embodiment 1.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A balancing valve, characterized in that: include: The main valve body and the balancing valve core include: a left chamber and a right chamber; the main valve body is provided with oil port A, oil port of chamber A, oil port B, oil port of chamber B respectively; The main valve body is also provided with a first transverse oil passage and a second transverse oil passage respectively; The first transverse oil passage is respectively longitudinally penetrated by a first oil passage a, a second oil passage a, and a third oil passage a. An oil passage plug is provided at one end of the first oil passage a. The other end of the first oil passage a is communicated with the control cavity of the balancing valve spring on the left. An oil passage plug is provided at one end of the second oil passage a. When the balancing valve core 1 is in the middle position, the left position, the other end of the second oil passage a is cut off by the balancing valve core. When the balancing valve core moves rightward from a distance m to a distance m+n, the other end of the second oil passage a is in a gradually communicated state with the control cavity of the balancing valve spring on the left. An oil passage plug is provided at one end of the third oil passage a. The other end of the third oil passage a is communicated with the oil port A. A first one-way throttling valve core is provided on the first transverse oil passage at the intersection of the first transverse oil passage and the first oil passage a. The second transverse oil passage is respectively longitudinally penetrated by a first oil passage b, a second oil passage b, and a third oil passage b, an oil passage plug is provided at one end of the first oil passage b, and the other end of the first oil passage b is communicated with the control cavity of the balancing valve spring on the right side, an oil passage plug is provided at one end of the second oil passage b, when the balancing valve core is in the middle position, the right position, the other end of the second oil passage b is cut off by the balancing valve core, when the balancing valve core moves to the left from a distance of m to a distance of m+n, the other end of the second oil passage b is in a gradually communicated state with the control cavity of the balancing valve spring on the right side, an oil passage plug is provided at one end of the third oil passage b, and the other end of the third oil passage b is communicated with the oil port B, and a second one-way throttling valve core is provided on the second transverse oil passage at the intersection of the second transverse oil passage and the first oil passage b; The inlet of the first one-way throttle valve core and the second one-way throttle valve core is provided with a first damping hole, and the side wall is provided with a second damping hole.

2. A balancing valve according to claim 1, characterized in that: A third damping hole is arranged in the second oil passage a.

3. A balancing valve according to claim 1, characterized in that: A third damping hole is arranged in the second oil passage b.

4. A balancing valve according to claim 1, characterized in that: The larger the diameter of the first damping hole is, the faster the moving speed of the balancing valve core is, and the faster the action response speed of the motor is.

5. A balancing valve according to claim 1, characterized in that: The larger the diameter of the second damping hole is, the faster the moving speed of the balancing valve core is, and the faster the action response speed of the motor is.

6. A balancing valve according to claim 1, characterized in that: The smaller the distance m between the end face of the balancing valve core and one side of the second oil passage a when the balancing valve core is in the middle position, the earlier the balancing valve core closes the second oil passage a during the resetting process.

7. A balancing valve according to claim 1, characterized in that: The smaller the distance m between the end face of the balancing valve core and one side of the second oil passage b when the balancing valve core is in the middle position, the earlier the balancing valve core closes the second oil passage b during the resetting process.

8. A working method of a balancing valve according to any one of claims 1 to 7, characterized in that: Specifically include: When the high-pressure oil enters the oil port A of the balancing valve, it pushes the one-way valve core in the left chamber to move to the left, and the high-pressure oil flows from the connected oil port of the A chamber into the A port of the motor, pushing the motor to rotate the parts. At this time, the oil port B of the balancing valve is closed, and the return oil from the B port of the motor cannot flow out of the balancing valve; at the same time, the high-pressure oil enters the first lateral oil channel through the third oil channel a. Since the second oil channel a is cut off by the balancing valve core, the high-pressure oil reaches the first one-way throttle valve core, overcomes the preload spring force of the first one-way throttle valve core, opens the first one-way throttle valve core, and enters the control chamber of the balancing valve spring on the left through the first oil channel a. After the pressure in the control chamber is increased, the balancing valve core is pushed to move rightward. The balancing valve core moving rightward pushes the oil in the control chamber of the balancing valve spring on the right side through the first oil passage b to the second one-way throttle valve core. At this time, the second one-way throttle valve core is cut off and the second oil passage b is cut off. The oil flows out through the second damping hole and the first damping hole on the second one-way throttle valve core, and flows into the oil port B through the third oil passage b, and flows out from the oil port B. The oil port B of the balancing valve is slowly connected with the oil port of the B chamber, and the second oil passage a is gradually connected. The return oil of the B port of the motor flows out from the slowly connected oil port B, so as to realize the smooth start of the motor. When the high-pressure oil supply to the oil port A of the balancing valve stops, the motor rotating parts continue to rotate under the action of inertia, and the oil port B still has the return oil from the B port of the motor flowing out. The balancing valve core is reset to the left under the spring force of the balancing valve spring on the right, and negative pressure is generated in the control chamber of the balancing valve spring on the right. The second one-way throttle valve core opens and the second oil channel b is cut off, and the oil flows into the control chamber on the right through the first oil channel b for oil replenishment; at the same time, the first one-way throttle valve core is cut off, and the oil in the control chamber of the balancing valve spring on the left flows from the first oil channel a through the second damping hole on the first one-way throttle valve core, the first damping hole and the second oil channel a to the A chamber oil port, until the left-moving balancing valve core gradually closes the second oil channel a, and the balancing valve core returns to the middle position.

9. The working method according to claim 8, characterized in that: When the balancing valve core moves to the left to the range of (s0-mn)≤s≤(s0-m), the second oil passage a is gradually closed, and the oil in the left control chamber is discharged through the damping hole of the first one-way throttle valve core on the first oil passage a and the second oil passage a back to the oil port of chamber A, and the resetting speed of the balancing valve core is gradually reduced; When the balancing valve core moves to the left to the range of s≤(s0-mn), the second oil channel a is completely closed, and the oil in the left control chamber passes through the first oil channel a to reach the first one-way throttle valve core. At this time, the hydraulic pressure acting on the first one-way throttle valve core is not enough to overcome the preload spring force, and the oil passes through the second damping hole and the first damping hole on the first one-way throttle valve core, passes through the first one-way throttle valve core, and then returns to the oil port of the A chamber through the first oil channel a for discharge. The balancing valve core is slowly reset, the oil port B is gradually closed, and the motor is gradually stopped; wherein, s0 is the total displacement distance of the balancing valve core, m is the distance between the end face of the balancing valve core and one side of the second oil channel a or the second oil channel b when the balancing valve core is in the middle position, n is the groove width of the second oil channel a or the second oil channel b, and s is the moving distance of the balancing valve core.

10. A motor, characterized in that: A balancing valve comprising any one of claims 1 to 7.

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