Pilot-operated type oil feeding and discharging independent control flow distribution system, motor and control method

Abstract

The invention relates to the technical field of valve control hydraulic motor digital flow distribution, and particularly discloses a pilot-operated type oil inlet and outlet independent control flow distribution system, a motor and a control method. The flow distribution system comprises a control valve, an oil inlet main valve and an oil return main valve are arranged in the control valve, and a piston cavity is controlled between the oil inlet main valve and the oil return main valve through an operation control cavity; the oil inlet main valve is controlled by an oil inlet pilot valve; and the oil return main valve is controlled by the oil return pilot valve. A flow distribution system on a traditional hydraulic and cycloid motor is replaced, an electric control system is used for controlling a large-flow electromagnetic valve installed at an inlet and an outlet of a motor piston according to an input instruction and a motor spindle rotation angle, and the effective work stroke can be changed by changing the switching phase angle of an oil inlet high-pressure valve and an oil return low-pressure valve, so that the working efficiency is improved. And finally, functions of speed regulation, torque regulation and the like are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of digital flow distribution for valve-controlled hydraulic motors, and particularly to a flow distribution system, a motor, and a control method with independent control of pilot-operated inlet and outlet oil. Background Art

[0002] Currently, the flow distribution methods widely used in hydraulic motors are mainly mechanical flow distribution methods such as shaft flow distribution and end face flow distribution. Although these flow distribution methods are individually mature, with the development of hydraulic digitization and intelligence and the usage requirements for motors, requirements such as speed regulation and torque adjustment are put forward for motors, and traditional mechanical motors cannot meet these requirements.

[0003] In the patent with the publication number CN101968028A by Shanghai Jiao Tong University, it relates to a digital flow distribution and speed regulation type low-speed high-torque hydraulic motor, and it has proposed a method for realizing digital flow distribution by using two-position three-way high-speed switching solenoid valves. However, since this control method controls the inlet and outlet oil of each cylinder with only one valve, although the functions of speed regulation and torque adjustment are realized, because each cylinder is controlled by one valve, and since the inlet and outlet oil valves can only switch simultaneously, there is a process where the two valves are opened simultaneously during the opening and closing process of the valves, causing high-pressure oil to directly flow into the low-pressure pipeline, resulting in energy loss. In addition, this pressure increase and decrease are realized by the on-off of the solenoid valve, and there is a relatively large pressure impact on the piston chamber during the switching process of the high and low-pressure pipelines, affecting the service life of the motor, and this type of motor cannot realize functions such as locking and creep control. Summary of the Invention

[0004] The purpose of the present invention is to provide a flow distribution system, a motor, and a control method with independent control of pilot-operated inlet and outlet oil. The present invention can replace the flow distribution system on traditional hydraulic and cycloidal motors. The present invention uses an electric control system to control the large-flow solenoid valves installed at the inlet and outlet of the motor piston according to the input command and the rotation angle of the motor main shaft. By changing the switching phase angle of the inlet high-pressure valve and the return low-pressure valve, the effective working stroke can be changed, and finally functions such as speed regulation and torque adjustment can be realized.

[0005] The present invention adopts the following technical solutions to achieve the invention purpose: A valve-controlled hydraulic flow distribution system with independent control of pilot-operated inlet and outlet oil, including a control valve. An inlet main valve and a return main valve are arranged in the control valve, and the piston chamber is controlled through an operation control chamber between the inlet main valve and the return main valve; the inlet main valve is controlled by an inlet pilot valve; the return main valve is controlled by a return pilot valve.

[0006] In the aforementioned valve-controlled hydraulic flow distribution system with pilot-operated independent control of inlet and outlet oil, inside the control valve, an inlet main valve control chamber is provided at the top of the inlet main valve, and an inlet chamber is provided at the lower part; a return main valve control chamber is provided at the top of the return main valve, and a return chamber is provided at the lower part; and springs in a compressed state are respectively provided in the inlet main valve control chamber and the return main valve control chamber to push the inlet main valve and the return main valve; the piston diameters D1 of both the inlet main valve and the return main valve are larger than the diameter D2 of the flow passage hole.

[0007] In the aforementioned valve-controlled hydraulic flow distribution system with pilot-operated independent control of inlet and outlet oil, the inlet pilot valve is a two-position three-way normally open solenoid valve, and the return pilot valve is a two-position three-way normally closed solenoid valve; the inlet port and the inlet chamber of the inlet pilot valve are connected to the high-pressure pipeline P h communicate, and the outlet port of the inlet pilot valve is connected to the inlet main valve control chamber; the inlet port of the return pilot valve is connected to the high-pressure pipeline P h communicate, and the outlet port of the return pilot valve is connected to the return main valve control chamber; the return chamber is connected to the low-pressure pipeline P l communicate; the return ports of both the inlet pilot valve and the return pilot valve are connected to the atmosphere.

[0008] In the aforementioned valve-controlled hydraulic flow distribution system with pilot-operated independent control of inlet and outlet oil, the low-pressure hydraulic pressure acting on the D1 - D2 annular belt of the low-pressure return main valve is greater than the spring force at its other end.

[0009] A valve-controlled hydraulic flow distribution motor with pilot-operated independent control of inlet and outlet oil, the motor is a hydraulic motor or a cycloid motor; a set of the aforementioned valve-controlled hydraulic flow distribution systems with pilot-operated independent control of inlet and outlet oil is respectively provided for each piston chamber of the hydraulic motor or each working chamber of the cycloid motor.

[0010] In the aforementioned valve-controlled hydraulic flow distribution motor with pilot-operated independent control of inlet and outlet oil, when the motor is a hydraulic motor, an absolute angle sensor is provided on the main shaft of the motor; a high-pressure pressure sensor is provided in the high-pressure pipeline P h ; a low-pressure pressure sensor is provided in the chamber connected to the atmosphere; a piston chamber pressure sensor and a piston chamber pressure and temperature sensor are provided on the connecting chamber path between the operation control chamber and the piston chamber; the absolute angle sensor, the high-pressure pressure sensor, the low-pressure pressure sensor, the piston chamber pressure sensor, the piston chamber pressure and temperature sensor, the inlet pilot valve, and the return pilot valve are all connected to the ECU.

[0011] A valve-controlled hydraulic flow distribution control method with pilot-operated independent control of inlet and outlet oil, including controlling the aforementioned valve-controlled hydraulic flow distribution motor by using the following method: When the inlet pilot valve and the return pilot valve are not energized, the inlet pilot valve is in the normally open position, and the inlet main valve control chamber is connected to the high-pressure pipeline P hThey are connected. Under the action of this high pressure, the main inlet valve is in the closed state, and high-pressure oil cannot enter the piston chamber. At this time, the pilot oil return valve is in the normally closed state, and the control chamber of the main oil return valve is connected to the low-pressure pipeline P l They are connected. The main oil return valve moves upward under the pressure of the low-pressure pipeline P l and the main oil return valve opens. At this time, the motor is in the idling state; When the motor is working normally, the ECU controls the opening and closing of the main inlet valve and the main oil return valve according to the angular displacement information of the absolute angle sensor and the motor speed or torque command signal, so as to control the effective working high-pressure stroke of the piston in the piston cylinder, thereby controlling the speed or torque of the motor.

[0012] In the aforementioned valve-controlled hydraulic flow control method with independent control of pilot-type inlet and outlet oil, it also includes that when the piston reaches the top dead center, the pilot oil return valve of the flow control system corresponding to this piston is electrified at this time, the control chamber of the main oil return valve is connected to high pressure, and the main oil return valve closes. At the same time, the pilot inlet valve is also electrified, the control chamber of the main inlet valve is connected to low pressure, and the oil pressure in the inlet chamber pushes the main inlet valve upward to open the main inlet valve. High-pressure oil enters the piston chamber through the operation control chamber, pushing the piston downward to output power; at a certain moment K point when the piston reaches the bottom dead center, control the pilot inlet valve and the pilot oil return valve to be powered off at the same time. At the same time, the control chamber of the main inlet valve is connected to high pressure. Under the combined action of high-pressure oil and spring force, the main inlet valve closes. At the same time, the control chamber of the main oil return valve is connected to the atmosphere and moves upward under the action of the low-pressure of the oil return. The main oil return valve opens. Before the piston reaches the bottom dead center, as the piston moves downward, low-pressure oil enters the piston chamber through the main oil return valve; after the piston reaches the bottom dead center and the piston moves upward, the motor pushes the oil in the piston chamber to the low-pressure pipeline P l until the piston returns to the top dead center. In the stage from point K until it returns to the top dead center, the corresponding piston does not do work and is in the idling state.

[0013] In the aforementioned valve-controlled hydraulic flow control method with independent control of pilot-type inlet and outlet oil, the point K is the α angle. α can vary arbitrarily between π / 2 and 3π / 2 according to the control command of the ECU. When α = π, the motor outputs the maximum power. When α = π / 2, the motor output power is 1 / 2 of the rated power. When α = 0, the motor output power is zero; When the motor takes speed as the control target, the α angle is controlled according to the control command of the ECU. When the speed is lower than the target value, increase the α angle to increase the effective working stroke of the motor. When the speed is greater than the target value, decrease the α angle to reduce the effective working stroke of the motor; by the aforementioned method, changing the target value can steplessly adjust the speed of the motor; When the motor takes torque as the control target, adopt the above method to control the effective working time of the piston to control the peak pressure in the piston chamber, and the torque can be steplessly adjusted.

[0014] In the aforementioned valve-controlled hydraulic flow distribution control method with pilot-operated independent control of inlet and outlet oil, the motor realizes corresponding functions according to the following method: Close all the inlet main valves of the motor and open all the outlet main valves. At this time, the motor is in an idling state, realizing the idling function. Set all the inlet main valves and outlet main valves of the motor in the closed state. At this time, each piston cylinder of the motor is in a locked state, and the motor is locked, realizing the locking function. Control different piston cylinders to enter the corresponding working state according to the angular position of the motor main shaft. The motor can rotate forward or backward, realizing the forward and reverse rotation function. When the motor is in the locked state, briefly open and close the inlet main valve corresponding to the piston cylinder in the power output state and the outlet main valve corresponding to the piston cylinder in the oil discharge state at the same time. The motor can rotate slightly, and the creeping angle of the slight rotation is determined by the length of this short time, realizing the creeping control.

[0015] In the aforementioned valve-controlled hydraulic flow distribution control method with pilot-operated independent control of inlet and outlet oil, the motor is a five-star hydraulic motor or a seven-star hydraulic motor.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Through the present invention, a traditional motor, which is a pure actuator, can be upgraded to a control component. By adopting the technology of the present invention, a traditional fixed-displacement motor can be changed into a stepless variable motor. After the improvement, not only its speed can be controlled, but also its torque can be controlled. In addition, the motor adopting the flow distribution system provided by the present invention also has an idling function, a locking function, a forward and reverse rotation control function, and a creeping control function, greatly expanding the application modes of traditional hydraulic / cycloid motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present invention (illustrated as a five-star hydraulic motor, and taking the structural setting of the flow distribution system of 1 piston as an example, omitting the flow distribution systems of the other 4 pistons with the same structure); Figure 2 is Figure 1 an enlarged schematic diagram of the connection structure of the control valve, the inlet pilot valve, and the outlet pilot valve in Figure 3 is a schematic control structure diagram of the present invention; Figure 4 is a schematic diagram (corresponding up and down) of the relationship between the piston displacement, the control signals of each valve (automatically provided after being judged by the ECU), and the piston chamber pressure of the present invention; The reference signs in the drawings are: hydraulic motor 1, piston cylinder 101, crankshaft 102, connecting rod 103, piston 104; piston chamber 105; absolute angle sensor 2; high-pressure pressure sensor 3; low-pressure pressure sensor 4; piston chamber pressure sensor 5; piston chamber temperature sensor 6; control valve 7, operation control chamber 701; oil inlet chamber 702; oil return chamber 703; oil inlet main valve 704; oil return main valve 705; spring 706; oil inlet main valve control chamber 707; oil return main valve control chamber 708; oil inlet pilot valve 8; oil return pilot valve 9; flow distribution system 10. Detailed implementation manners

[0018] Next, the technical solutions in the embodiments of the invention will be clearly and completely described in conjunction with the drawings in the embodiments of the invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments.

[0019] Embodiment 1. A valve-controlled hydraulic flow distribution motor with independent control of pilot-operated oil inlet and outlet. This motor is an improvement on the existing mechanical flow distribution five-star motor. The improvement point is that the mechanical flow distribution system of the motor is completely replaced by a valve-controlled hydraulic flow distribution system with independent control of pilot-operated oil inlet and outlet (hereinafter referred to as the flow distribution system 10) for electronic control digital flow distribution.

[0020] Specifically, the structure is as Figure 1-2 shown, including a hydraulic motor 1 with five pistons. Each piston chamber 105 of the hydraulic motor 1 is provided with a set of flow distribution systems 10; the flow distribution system 10 includes five control valves 7. An oil inlet main valve 704 and an oil return main valve 705 are arranged in the control valve 7. The piston chamber 105 is controlled through the operation control chamber 701 between the oil inlet main valve 704 and the oil return main valve 705; the oil inlet main valve 704 is controlled by the oil inlet pilot valve 8; the oil return main valve 705 is controlled by the oil return pilot valve 9.

[0021] In this motor, an angular displacement sensor is arranged on the main shaft of the motor, the traditional mechanical flow distribution mechanism is cancelled, and a set of digital flow distribution systems are arranged in each oil cylinder chamber. The digital flow distribution system is composed of a two-position three-way normally open pilot solenoid valve controlling an oil inlet high-pressure main valve and a two-position three-way normally closed pilot solenoid valve controlling an oil return (low-pressure) main valve. The purpose of the two-stage valve is to increase the control flow rate.

[0022] In the control valve 7, an oil inlet main valve control chamber 707 is arranged at the top of the oil inlet main valve 704, and an oil inlet chamber 702 is arranged at the lower part; an oil return main valve control chamber 708 is arranged at the top of the oil return main valve 705, and an oil return chamber 703 is arranged at the lower part; and compression springs 706 are respectively arranged in the oil inlet main valve control chamber 707 and the oil return main valve control chamber 708 to push against the oil inlet main valve 704 and the oil return main valve 705; the piston diameters D1 of the oil inlet main valve 704 and the oil return main valve 705 are both larger than the flow passage hole diameter D2.

[0023] The inlet pilot valve 8 is a two-position three-way normally open solenoid valve, and the outlet pilot valve 9 is a two-position three-way normally closed solenoid valve; the inlet of the inlet pilot valve 8 and the inlet chamber 702 are connected to the high-pressure pipeline P h communicate, and the outlet of the inlet pilot valve 8 is connected to the control chamber 707 of the inlet main valve; the inlet of the outlet pilot valve 9 is connected to the high-pressure pipeline P h communicate, and the outlet of the outlet pilot valve 9 is connected to the control chamber 708 of the outlet main valve; the outlet chamber 703 is connected to the low-pressure pipeline P l communicate; the return ports of the inlet pilot valve 8 and the outlet pilot valve 9 are both connected to the atmosphere; and the low-pressure hydraulic pressure acting on the D1-D2 ring of the outlet main valve 705 is greater than the spring force of the spring 706 at the other end of the outlet main valve 705.

[0024] An absolute angle sensor 2 is provided on the main shaft of the hydraulic motor 1; a high-pressure pressure sensor 3 is provided in the high-pressure pipeline P h ; a low-pressure pressure sensor 4 is provided in the chamber connected to the atmosphere; a piston chamber pressure sensor 5 and a piston chamber temperature sensor 6 are provided on the connecting chamber path between the operation control chamber 701 and the piston chamber 105; the absolute angle sensor 2, the high-pressure pressure sensor 3, the low-pressure pressure sensor 4, the piston chamber pressure sensor 5, the piston chamber temperature sensor 6, the inlet pilot valve 8 and the outlet pilot valve 9 are all connected to the ECU. The control method of the ECU for each component is shown in Figure 3 Figure 3 Among them, the 5 groups of inlet pilot valves 8 and outlet pilot valves 9 indicate that the ECU controller is respectively connected to 10 pilot solenoid valves.

[0025] For the above-mentioned pilot type inlet and outlet oil independent control valve-controlled hydraulic flow distribution motor, the following method is used for control: When the inlet pilot valve 8 and the outlet pilot valve 9 are not energized, the inlet pilot valve 8 is in the normally open position, and the control chamber 707 of the inlet main valve is connected to the high-pressure pipeline P h communicate. Under the action of this high pressure, the inlet main valve 704 is in the closed state, and the high-pressure oil cannot enter the piston chamber 105. At this time, the outlet pilot valve 9 is in the normally closed state, and the control chamber 708 of the outlet main valve is connected to the low-pressure pipeline P l communicate. The outlet main valve 705 moves upward under the action of the low-pressure pipeline pressure, and the outlet main valve 705 opens. At this time, the hydraulic motor 1 is in the idling state; among them, the high-pressure pipeline P h provides high-pressure oil, and the low-pressure pipeline P l provides low-pressure oil; When the hydraulic motor 1 is operating normally, the ECU controls the opening and closing of the inlet main valve 704 and the outlet main valve 705 according to the angular displacement information of the absolute angle sensor 2 and the rotational speed or torque command signal of the hydraulic motor 1, thereby controlling the effective working high-pressure stroke of the piston in the piston cylinder 101, and thus controlling the rotational speed or torque of the hydraulic motor 1.

[0026] The specific working principle and control method are as follows. Refer to Figure 4 , when the piston 104 reaches the top dead center, at this time the return oil pilot valve 9 of the port plate assembly 10 corresponding to this piston 104 is energized, the control chamber 708 of the outlet main valve is connected to high pressure, and the outlet main valve 705 closes. At the same time, the inlet pilot valve 8 is also energized, the control chamber 707 of the inlet main valve is connected to low pressure, and the oil pressure in the inlet chamber 702 pushes the inlet main valve 704 upward to open the inlet main valve 704. The high-pressure oil enters the piston chamber 105 through the operation control chamber 701, pushing the piston 104 downward to output power; at a certain moment K point when the piston 104 reaches the bottom dead center, control the inlet pilot valve 8 and the return oil pilot valve 9 to be de-energized at the same time. At the same time, the control chamber 707 of the inlet main valve is connected to high pressure. Under the combined action of the high-pressure oil and the spring force, the inlet main valve 704 closes. At the same time, the control chamber 708 of the outlet main valve is connected to the atmosphere and moves upward under the action of the low outlet oil pressure, and the outlet main valve 705 opens. Before the piston 104 reaches the bottom dead center, as the piston 104 moves downward, the low-pressure oil enters the piston chamber 105 through the outlet main valve 705; after the piston 104 reaches the bottom dead center and the piston 104 moves upward, the hydraulic motor 1 pushes the oil in the piston chamber 105 into the low-pressure pipeline P l , until the piston 104 returns to the top dead center. In the stage from point K until it returns to the top dead center, the corresponding piston 104 does not do work and is in an idling state.

[0027] The point K is the α angle, and α can vary arbitrarily between π / 2 and 3π / 2 according to the control command of the ECU. When α = π, the hydraulic motor 1 outputs the maximum power. When α = π / 2, the output power of the hydraulic motor 1 is 1 / 2 of the rated power. When α = 0, the output power of the hydraulic motor 1 is zero; When the rotational speed of the hydraulic motor 1 is the control target, the α angle is controlled according to the control command of the ECU. When the rotational speed is lower than the target value, increase the α angle to increase the effective working stroke of the hydraulic motor 1. When the rotational speed is higher than the target value, decrease the α angle to reduce the effective working stroke of the hydraulic motor 1; by the foregoing method, by changing the target value, the rotational speed of the hydraulic motor 1 can be steplessly adjusted.

[0028] When the torque of the hydraulic motor 1 is the control target, the above method is used to control the effective working time of the piston 104 and control the peak pressure of the piston chamber 105, and the torque can be steplessly adjusted.

[0029] In addition to the above main functions, the hydraulic motor 1 can also achieve corresponding functions according to the following methods: Close all the oil inlet main valves 704 of the hydraulic motor 1 and open all the oil return main valves 705. At this time, the hydraulic motor 1 is in an idling state, achieving the idling function; Set all the oil inlet main valves 704 and oil return main valves 705 of the hydraulic motor 1 in the closed state. At this time, each piston cylinder 101 of the hydraulic motor 1 is in a locked state, and the hydraulic motor 1 is locked, achieving the locking function; Control different piston cylinders 101 to enter the corresponding working states according to the angular position of the motor main shaft. The hydraulic motor 1 can rotate forward or backward, achieving the forward and reverse rotation function; When the hydraulic motor 1 is in the locked state, briefly open and close the oil inlet main valve 704 corresponding to the piston cylinder 101 in the power output state and the oil return main valve 705 corresponding to the piston cylinder 101 in the oil discharge state at the same time. The hydraulic motor 1 can then rotate slightly, and the creep angle of the slight rotation is determined by the length of this short time, achieving creep control.

[0030] Embodiment 2. A pilot-operated independently controlled valve-controlled hydraulic distribution seven-star motor. This motor is an improvement on the existing mechanical distribution seven-star motor. The improvement point is that the mechanical distribution system of the seven-star motor is completely replaced by a valve-controlled hydraulic distribution system (hereinafter referred to as the distribution system 10) with pilot-operated independently controlled oil inlet and outlet for electronic control digital distribution. Its working principle and control method are the same as those described in Embodiment 1.

[0031] Embodiment 3. A pilot-operated independently controlled valve-controlled hydraulic distribution cycloid motor. This motor is an improvement on the existing mechanical distribution cycloid motor. The improvement point is that the mechanical distribution system of the cycloid motor is completely replaced by a valve-controlled hydraulic distribution system (hereinafter referred to as the distribution system 10) with pilot-operated independently controlled oil inlet and outlet for electronic control digital distribution. Its working principle and control method are similar to those described in Embodiment 1, except that in Embodiment 1, the piston chamber is operated, while for the cycloid motor, it is the working chamber.

[0032] The above is only a preferred specific embodiment of the invention, but the protection scope of the invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the invention, according to the technical solution and its concept of the invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the invention.

Claims

1. A valve-controlled hydraulic flow distribution system with independent control of pilot-operated inlet and outlet oil, characterized in that: It includes a control valve (7). An oil inlet main valve (704) and an oil return main valve (705) are arranged inside the control valve (7). The piston chamber (105) is controlled through an operation control chamber (701) between the oil inlet main valve (704) and the oil return main valve (705); the oil inlet main valve (704) is controlled by an oil inlet pilot valve (8); the oil return main valve (705) is controlled by an oil return pilot valve (9).

2. The pilot-operated inlet and outlet oil independent control valve-controlled hydraulic flow distribution system according to claim 1, characterized in that: Inside the control valve (7), an oil inlet main valve control chamber (707) is provided at the top of the oil inlet main valve (704), and an oil inlet chamber (702) is provided at the lower part; an oil return main valve control chamber (708) is provided at the top of the oil return main valve (705), and an oil return chamber (703) is provided at the lower part; and springs (706) in a compressed state are respectively arranged inside the oil inlet main valve control chamber (707) and the oil return main valve control chamber (708) to push against the oil inlet main valve (704) and the oil return main valve (705); the piston diameters D1 of the oil inlet main valve (704) and the oil return main valve (705) are both larger than the flow channel hole diameter D2.

3. The pilot-operated inlet and outlet oil independent control valve-controlled hydraulic flow distribution system according to claim 2, wherein: The inlet pilot valve (8) is a two-position three-way normally open solenoid valve, and the outlet pilot valve (9) is a two-position three-way normally closed solenoid valve; the inlet port of the inlet pilot valve (8) and the inlet oil cavity (702) are connected to the high-pressure pipeline P h communicate, and the outlet port of the inlet pilot valve (8) is connected to the control cavity (707) of the inlet main valve; the inlet port of the outlet pilot valve (9) is connected to the high-pressure pipeline P h communicate, and the outlet port of the outlet pilot valve (9) is connected to the control cavity (708) of the outlet main valve; the outlet oil cavity (703) is connected to the low-pressure pipeline P l communicate; the outlet ports of the inlet pilot valve (8) and the outlet pilot valve (9) are both connected to the atmosphere; the low-pressure liquid pressure acting on the D1-D2 ring of the outlet main valve (705) is greater than the spring force of the spring (706) at the other end of the outlet main valve (705).

4. A valve-controlled hydraulic flow distribution motor with independent control of pilot-operated inlet and outlet oil, characterized in that: The motor is a hydraulic motor or a cycloid motor; each piston chamber of the hydraulic motor or each working chamber of the cycloid motor is respectively provided with a set of valve-controlled hydraulic flow distribution system with independent control of inlet and outlet oil by the pilot type as described in claim 3.

5. The pilot-operated inlet and outlet oil independent control valve-controlled hydraulic flow distribution motor according to claim 4, characterized in that: When the motor is a hydraulic motor, an absolute angle sensor (2) is provided on the main shaft of the motor; a high-pressure pressure sensor (3) is provided in the high-pressure pipeline P h ; a low-pressure pressure sensor (4) is provided in the cavity connected to the atmosphere; a piston chamber pressure sensor (5) and a piston chamber pressure and temperature sensor (6) are provided on the communication pipeline between the operation control chamber (701) and the piston chamber (105); the absolute angle sensor (2), the high-pressure pressure sensor (3), the low-pressure pressure sensor (4), the piston chamber pressure sensor (5), the piston chamber pressure and temperature sensor (6), the oil inlet pilot valve (8) and the oil return pilot valve (9) are all connected to the ECU.

6. A valve-controlled hydraulic flow distribution control method with independent control of pilot-operated inlet and outlet oil, characterized in that: It includes controlling the valve-controlled hydraulic flow distribution motor with independent control of inlet and outlet oil by the pilot type as described in claim 5 by adopting the following method: When the oil inlet pilot valve (8) and the oil return pilot valve (9) are not energized, the oil inlet pilot valve (8) is in the normally open position, and the oil inlet main valve control chamber (707) is connected to the high-pressure pipeline P h Under the action of the high pressure, the main oil inlet valve (704) is in a closed state, and the high-pressure oil cannot enter the piston chamber (105). At this time, the oil return pilot valve (9) is in a normally closed state, and the main oil return valve control chamber (708) is connected to the low-pressure pipeline P l The return oil main valve (705) is connected to the low pressure pipeline P l It moves upward under the action of pressure, and the main oil return valve (705) opens. At this time, the motor is in an idling state; When the motor is working normally, the ECU controls the opening and closing of the oil inlet main valve (704) and the oil return main valve (705) according to the angular displacement information of the absolute value angle sensor (2) and the motor speed or torque command signal, so as to control the effective working high-pressure stroke of the piston in the piston cylinder (101), and thus control the speed or torque of the motor.

7. The pilot-operated independent control method for inlet and outlet oil valve-controlled hydraulic flow distribution according to claim 6, characterized in that: It also includes that when the piston (104) reaches the top dead center, the oil return pilot valve (9) of the flow distribution system (10) corresponding to the piston (104) is electrified at this time, the high pressure is applied to the oil return main valve control chamber (708), the oil return main valve (705) is closed. At the same time, the oil inlet pilot valve (8) is also electrified, the oil inlet main valve control chamber (707) is connected to the low pressure, and the oil pressure in the oil inlet chamber (702) pushes the oil inlet main valve (704) upward to open the oil inlet main valve (704). The high-pressure oil enters the piston chamber (105) through the operation control chamber (701) to push the piston (104) to move downward and output power. At a certain moment K when the piston (104) reaches the bottom dead center, the oil inlet pilot valve (8) and the oil return pilot valve (9) are simultaneously de-energized. At the same time, the oil inlet main valve control chamber (707) is connected to the high pressure. Under the combined action of the high-pressure oil and the spring force, the oil inlet main valve (704) is closed. At the same time, the oil return main valve control chamber (708) is connected to the atmosphere and moves upward under the action of the oil return low pressure, and the oil return main valve (705) is opened. Before the piston (104) reaches the bottom dead center, as the piston (104) moves downward, the low-pressure oil enters the piston chamber (105) through the oil return main valve (705). After the piston (104) reaches the bottom dead center and the piston (104) moves upward, the motor pushes the oil in the piston chamber (105) to the low-pressure pipeline P l , until the piston (104) returns to the top dead center. In the stage from point K until it returns to the top dead center, the corresponding piston (104) does not do work and is in an idling state.

8. The pilot-operated independent control method for inlet and outlet oil valve-controlled hydraulic flow distribution according to claim 7, characterized in that: The point K is the α angle. α can arbitrarily change between π / 2 and 3π / 2 according to the control command of the ECU. When α = π, the motor output power is the largest. When α = π / 2, the motor output power is 1 / 2 of the rated power. When α = 0, the motor output power is zero; When the motor takes the speed as the control target, the α angle is controlled according to the control command of the ECU. When the speed is lower than the target value, the α angle is increased to increase the effective working stroke of the motor. When the speed is higher than the target value, the α angle is decreased to decrease the effective working stroke of the motor; by the foregoing method, by changing the target value, the speed of the motor can be steplessly adjusted; When the motor takes the torque as the control target, the above method is adopted to control the effective working time of the piston (104) and control the peak pressure of the piston chamber (105), so as to steplessly adjust the torque.

9. The pilot-operated independent control method for inlet and outlet oil valve-controlled hydraulic flow distribution according to claim 8, characterized in that: The motor realizes the corresponding functions according to the following method: Close all the oil inlet main valves (704) of the motor and open all the oil return main valves (705). At this time, the motor is in an idling state, realizing the idling function; Set all the oil inlet main valves (704) and oil return main valves (705) of the motor in a closed state. At this time, each piston cylinder (101) of the motor is in a locked state, and the motor is locked, realizing the locking function; Controlling different piston cylinders (101) to enter corresponding working states according to the angular position of the motor main shaft, the motor can rotate forward or backward to achieve the forward and reverse functions; When the motor is in a locked state, the oil inlet main valve (704) corresponding to the piston cylinder (101) in the power output state and the oil return main valve (705) corresponding to the piston cylinder (101) in the oil discharge state are briefly switched on and off at the same time, and the motor can rotate slightly. The creeping angle of the slight rotation is determined by the length of this short time to achieve creeping control.

10. The pilot-operated independent control method for inlet and outlet oil valve-controlled hydraulic flow distribution according to claim 9, characterized in that: The motor is a five-star hydraulic motor or a seven-star hydraulic motor.

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