Oil way on-off control method and device, bidirectional hydraulic equipment and self-energy-feedback brake device

Abstract

The invention relates to an oil way on-off control method and device, two-way hydraulic equipment and a self-energy-feedback brake device. The oil way on-off control device comprises a pressure difference control device and a pressure control device, and an outlet Py of the pressure control device is communicated with a variable displacement mechanism of a two-way variable displacement hydraulic pump / motor through a control oil way; an inlet PA and an inlet PB of the pressure difference control device are respectively communicated with an oil port A and an oil port B of the two-way variable hydraulic pump / motor, and an outlet P0 of the pressure difference control device is communicated with an inlet Py of the pressure control device; according to the oil way on-off control device and method, when the rotation direction of the input shaft of the two-way variable hydraulic pump is changed or the high-pressure inlet of the two-way variable hydraulic motor is changed, the inlet and the outlet of the two-way variable hydraulic pump / motor are exchanged; and a variable displacement mechanism of the hydraulic variable displacement pump / variable displacement motor can be always communicated with a high-pressure outlet or a high-pressure inlet, and the hydraulic variable displacement pump / variable displacement motor is particularly suitable for meeting the bidirectional working requirement of the hydraulic variable displacement pump / motor when the rotating directions of a left airplane wheel and a right airplane wheel in a self-energy-feedback braking system of an airplane are opposite.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic transmission technology, and specifically to an oil circuit on-off control method and device, as well as a bidirectional variable hydraulic pump, a bidirectional variable hydraulic motor and a self-feeding brake device based on the method, which are intended to solve the problem of ensuring that a variable mechanism of a bidirectional variable hydraulic pump / motor always communicates with a high-pressure end when the input shaft or high-pressure inlet direction of the bidirectional variable hydraulic pump / motor changes, thereby improving the versatility and working stability of the equipment, and are particularly suitable for solving the bidirectional working requirements of a hydraulic variable pump / motor when the left and right wheels turn in opposite directions in an aircraft self-feeding brake system. Background Art

[0002] As the power element of the hydraulic system, the hydraulic pump is a device that converts mechanical energy into hydraulic energy. In the field of self-feeding brake technology, since the relative rotation directions of the left and right wheels of the aircraft are opposite, that is, when the left wheel rotates clockwise, the right wheel rotates counterclockwise, so the input shaft rotation directions of the self-feeding variable pump installed on the left and right wheels need to be opposite.

[0003] In the existing structure, a one-way variable pump is mostly used in the self-feeding brake device. When the input steering direction changes, the inlet and outlet of the hydraulic pump are interchanged, that is, the outlet becomes the inlet, and the inlet becomes the outlet. Since the internal structure of the one-way variable pump is not symmetrical, changing the rotation direction of the input shaft will damage the one-way variable pump. Therefore, when it is necessary to realize the two-way output variable function, one-way variable pumps with different rotation directions are often installed for the left and right wheels respectively, that is, two types of one-way variable hydraulic pumps with different input shaft rotation directions are developed, which are not very universal.

[0004] In order to simultaneously meet the use requirements of the left and right wheel output shafts rotating in opposite directions, the variable pump needs to be able to work normally even when its input shaft switches direction, and a bidirectional variable pump is proposed. The variable mechanism of the bidirectional variable pump is always in communication with the high-pressure outlet. How to ensure that the variable mechanism is in communication with the high-pressure end when the high-pressure inlet of the bidirectional variable motor changes, and an oil circuit on-off control method and device are proposed.

[0005] It should be noted that the information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or suggestion in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0006] The present invention aims to provide an oil circuit on-off control method and device, as well as a bidirectional variable hydraulic pump, a bidirectional variable hydraulic motor and a self-feeding brake device based on the method / device, so as to solve the problem that when the input shaft of the bidirectional variable hydraulic pump changes the rotation direction or the bidirectional variable hydraulic motor changes the high-pressure inlet, the inlet and outlet of the bidirectional variable hydraulic pump / motor are interchanged, that is, the outlet becomes the inlet and the inlet becomes the outlet, the variable mechanism of the bidirectional variable hydraulic pump / motor is always in communication with the high-pressure end, that is, the bidirectional variable hydraulic pump can work normally in two rotation directions, the bidirectional variable hydraulic motor can realize normal work in two output shaft directions, and can effectively solve the use requirements of the opposite steering of the left and right wheels in the self-feeding brake device, and can make the variable pump work normally when its input shaft switches direction during normal forward and reverse, while improving the versatility of the product and reducing the development cost.

[0007] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present application provides an oil circuit on-off control method, which is applied to a bidirectional variable hydraulic pump or a bidirectional variable hydraulic motor, and the method comprises: (1) A pressure control device is provided, wherein the outlet Pk is connected to the variable mechanism of the bidirectional variable hydraulic pump or the bidirectional variable hydraulic motor through a control oil circuit, and the outlet T is connected to the oil tank through an oil return oil circuit; (2) a pressure differential control device is provided, wherein the inlet PA and the inlet PB are connected to the oil port A and the oil port B of the bidirectional variable hydraulic pump / motor through the oil inlet oil passage at the A port and the oil inlet oil passage at the B port, respectively, and the outlet P0 is connected to the inlet Py of the pressure control device; (3) The pressure difference control device enables the oil port with higher oil pressure among the oil port B of the oil port A to communicate with the pressure control device. The pressure control device controls the action of the variable mechanism according to the oil pressure value to ensure that the variable mechanism always maintains communication with the high-pressure oil port.

[0008] In a second aspect, the present invention provides an oil channel control device for a bidirectional variable hydraulic pump or a bidirectional variable hydraulic motor, the device comprising: A pressure differential control device, comprising a pressure differential control device valve seat, a pressure differential control device valve body, a pressure differential control device valve core, a pressure differential spring, an inlet PA, an inlet PB and an outlet P0; wherein the inlet PA and the inlet PB are respectively connected to the oil port A and the oil port B of a two-way variable hydraulic pump or a two-way variable hydraulic motor; the pressure differential control device valve core slides in the valve body according to the pressure differential value between the inlet PA and the inlet PB, and the position of the pressure differential control device valve core is changed, so that one of the inlet PA and the inlet PB is connected to the outlet P0 or both are disconnected from the outlet P0; A pressure control device, comprising a pressure control device valve seat, a pressure control device valve body, a pressure control device valve core, a pressure regulating spring, an inlet Py, an outlet Pk and an outlet T; wherein the inlet Py is connected to the outlet P0 of the pressure difference control device, the outlet Pk is connected to the variable mechanism of a two-way variable hydraulic pump or a two-way variable hydraulic motor through a control oil circuit, and the outlet T is connected to an oil tank; when the pressure of the inlet Py is lower than the set value of the pressure control device, the inlet Py is disconnected from the outlet Pk, and the outlet Pk is connected to the outlet T, and when the pressure of the inlet Py reaches the set value of the pressure control device, the inlet Py is connected to the outlet Pk, and the outlet Pk communicates with the follower chamber of the variable mechanism through the control oil circuit.

[0009] In a third aspect, the present invention provides a bidirectional variable hydraulic pump, the pump comprising: A two-way hydraulic device, which is used as a hydraulic pump, wherein the oil return chamber of the two-way hydraulic device communicates with the oil tank through the oil return oil passage of the housing; a variable mechanism, which is used to adjust the displacement of the hydraulic pump, the oil return chamber of the variable mechanism communicates with the oil return chamber of the bidirectional hydraulic device through the variable mechanism oil return oil circuit, and the follower chamber of the variable structure communicates with the oil circuit on-off device through the control oil circuit; An oil circuit on-off control device, as described in the second aspect above, wherein the outlet of the pressure control device of the oil circuit on-off control device communicates with the follower chamber of the variable mechanism through the control oil circuit, and the outlet of the pressure control device of the oil circuit on-off control device communicates with the oil tank through the return oil circuit; the inlet PA and the inlet PB of the pressure difference control device of the oil circuit on-off control device communicate with the oil port A and the oil port B of the bidirectional hydraulic device through the A port inlet oil circuit and the B port inlet oil circuit respectively, and the oil circuit on-off control device is used to control the on-off of the oil circuit between the variable mechanism and the bidirectional hydraulic device, so that the variable mechanism always maintains communication with the high-pressure oil port of the bidirectional hydraulic device; An oil tank is used to collect the return oil.

[0010] In a fourth aspect, the present invention provides a bidirectional variable hydraulic motor, the motor comprising: A bidirectional hydraulic device, which is used as a hydraulic motor, wherein the oil return chamber of the bidirectional hydraulic device communicates with the oil tank through the oil return oil passage of the housing; A variable mechanism, which is used to adjust the output torque and torque of the hydraulic motor, the return oil chamber of the variable mechanism communicates with the return oil chamber of the bidirectional hydraulic device through the variable mechanism return oil circuit, and the follower chamber of the variable structure communicates with the oil circuit on-off device through the control oil circuit; An oil circuit on-off control device, as described in the second aspect above, wherein the outlet of the pressure control device of the oil circuit on-off control device communicates with the follower chamber of the variable mechanism through the control oil circuit, and the outlet of the pressure control device of the oil circuit on-off control device communicates with the oil tank through the return oil circuit; the inlet PA and the inlet PB of the pressure difference control device of the oil circuit on-off control device communicate with the oil port A and the oil port B of the bidirectional hydraulic device through the A port inlet oil circuit and the B port inlet oil circuit respectively, and the oil circuit on-off control device is used to control the on-off of the oil circuit between the variable mechanism and the bidirectional hydraulic device, so that the variable mechanism always maintains communication with the high-pressure oil port of the bidirectional hydraulic device; An oil tank is used to collect the return oil.

[0011] In a fifth aspect, the present invention provides a self-powered braking device, the device comprising: One wheel; a mechanical energy extraction mechanism, which is connected to the wheel and the bidirectional variable hydraulic pump and is used to extract energy from the rotation of the wheel; a bidirectional variable displacement hydraulic pump, as described in the third aspect above, for converting mechanical energy into hydraulic energy or vice versa; A control valve, which connects the bidirectional variable hydraulic pump and the actuator and is used for on-off control of the oil circuit between the bidirectional variable hydraulic pump and the actuator; An actuator is used to brake the wheel.

[0012] The beneficial effects of this application are: 1. Ensure that when the input shaft or high-pressure inlet direction of the bidirectional variable hydraulic pump / motor changes, the variable mechanism always communicates with the high-pressure end to improve the working stability and reliability of the equipment; 2. Improve the versatility of products and reduce development costs; 3. Meet the requirement of opposite steering of left and right wheels in self-feeding brake device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 According to Embodiment 1 of the present application, a control principle diagram of an oil circuit on-off control method is shown; Figure 2 According to Example 2 of the present application, a structural principle diagram of an oil circuit on-off control device is shown; Figure 3 According to Embodiment 3 of the present application, a functional principle diagram of a bidirectional variable hydraulic pump is shown; Figure 4 According to Embodiment 4 of the present application, a functional principle diagram of a bidirectional variable hydraulic motor is shown; Figure 5 According to Example 5 of the present application, a structural schematic diagram of a left wheel self-feeding brake device is shown; Figure 6 According to Example 5 of the present application, a structural schematic diagram of a right wheel self-feeding braking device is shown. DETAILED DESCRIPTION

[0014] The technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention. Example 1

[0015] Embodiment 1 of the present invention provides an oil circuit on-off control method, which is applied to a bidirectional variable hydraulic pump / bidirectional variable hydraulic motor. Figure 1 , the method comprising: (1) A pressure control device a is provided, and an outlet Pk of the pressure control device a is connected to the variable mechanism of the bidirectional variable hydraulic pump / bidirectional variable hydraulic motor through a control oil circuit c, and an outlet T of the pressure control device a is connected to the oil tank through an oil return oil circuit d; (2) A pressure differential control device b is provided, wherein the inlet PA of the pressure differential control device b is connected to one of the oil ports A of the bidirectional variable hydraulic pump / bidirectional variable hydraulic motor through the A-port oil inlet oil line e, and the inlet PB is connected to the other oil port B of the bidirectional variable hydraulic pump / bidirectional variable hydraulic motor through the B-port oil inlet oil line f; (3) The pressure difference control device b enables the oil port with higher oil pressure between the oil port A and the oil port B to communicate with the inlet Py of the pressure control device a. The pressure control device a controls the action of the variable mechanism according to the oil pressure value to ensure that the variable mechanism always communicates with the oil port with higher oil pressure between the oil port A and the oil port B.

[0016] The working principle of the oil circuit on-off control method of the embodiment of the present invention is as follows: when the oil at the high-pressure outlet (or high-pressure inlet) of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) enters the high-pressure inlet PA of the pressure difference control device b through the A-port oil inlet oil circuit e, its valve core moves downward, and the oil circuit between the inlet PA and the outlet P0 is connected. When the pressure value is lower than the set pressure of the pressure control device a, the inlet Py is disconnected, and the outlet Pk is connected to the outlet T. At this time, the oil circuit between the high-pressure outlet (or high-pressure inlet) of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) and the control oil circuit c is disconnected. When the pressure value reaches the set pressure of the pressure control device a, the inlet Py is connected to the outlet Pk, and the oil enters the variable mechanism follower chamber of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) through the control oil circuit c.

[0017] Similarly, when the oil at the high-pressure outlet (or high-pressure inlet) of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) enters the inlet PB of the pressure difference control device b through the oil inlet f of port B, the valve core moves upward, and the oil circuit between the inlet PB and the outlet P0 is connected. When the pressure value is lower than the set pressure of the pressure control device a, the inlet Py is disconnected, and the outlet Pk is connected to the outlet T. At this time, the oil circuit between the high-pressure outlet (or high-pressure inlet) of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) and the control oil circuit c is disconnected. When the pressure value reaches the set pressure of the pressure control device a, the inlet Py is connected to the outlet Pk, and the oil enters the variable mechanism follower chamber of the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) through the control oil circuit c.

[0018] When the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) is not working, the pressures at the inlet PA and the inlet PB of the pressure difference control device b are equal, the valve core does not move and is in the middle position, and the inlet PA and the inlet PB are disconnected from the outlet P0. Example 2

[0019] Embodiment 2 of the present invention provides an oil circuit on-off control device for implementing the method of embodiment 1, see Figure 2 , the device includes a pressure control device a and a pressure difference control device b.

[0020] The pressure differential control device b includes: a pressure differential control device valve seat 201, a spring support seat 202, a left pressure differential spring 203, a right pressure differential spring 204, a pressure differential control device valve body 205, a first sealing ring 206, a second sealing ring 207, a pressure differential control device valve core 208, a third sealing ring 209, and a first plug 210; the pressure differential control device valve seat 201 is provided with an inlet PA, an inlet PB and an outlet P0. A PA hole 211 connected to the inlet PA and a PB hole 212 connected to the inlet PB are provided inside the valve seat 201 of the differential pressure control device. An a hole 213 connected to the PA hole 211, a b hole 214 connected to the PB hole 212, and a P0 hole 215 connected to the outlet P0 are provided inside the valve body 205 of the differential pressure control device. The first sealing ring 206 and the second sealing ring 207 are respectively used for sealing the oil circuits between the PA hole / a hole and the P0 hole, and the PB hole / b hole and the P0 hole. The third sealing ring 209 is used for sealing between the first plug 210 and the valve seat 201 of the differential pressure control device. A P0-Py oil circuit 216 connecting the outlet P0 and the inlet Py of the pressure control device a is also provided on the valve seat 201 of the differential pressure control device.

[0021] The pressure control device a includes: a fourth sealing ring 101, a fifth sealing ring 102, a sixth sealing ring 103, an adjusting screw 104, a locking nut 105, a pressure adjusting spring 106, a seventh sealing ring 107, a pressure control device valve seat 108, a pressure control device valve core 109, a pressure control device valve body 110, an eighth sealing ring 111, and a second plug 112. The pressure control device valve seat 108 is provided with an inlet Py, an outlet Pk, and an outlet T, and the inside of the pressure control device valve seat 108 is provided with a Py hole 113, a Pk hole 116, and a T hole 117 connected to the inlet Py, the outlet Pk, and the outlet T, respectively, and the inside of the pressure control device valve body 110 is provided with a c hole 114 connected to the Py hole 113 and a d hole 115 connected to the Pk hole 116. The fourth sealing ring 101 is used for sealing the oil between the P0-Py oil circuit 216 and the inlet Py, the fifth sealing ring 102 is used for sealing the outlet T, the sixth sealing ring 103 is used for sealing the outlet Pk, the seventh sealing ring 107 is used for sealing the left part of the oil chamber inside the valve body, and the eighth sealing ring 111 is used for sealing between the second plug 112 and the valve seat 108 of the pressure control device; in the pressure control device a, the preload force of the pressure regulating spring 14 is adjusted by setting the adjusting screw 104, so that the opening pressure of the pressure control device a can be adjusted according to the needs of use. When the oil pressure at the inlet Py is less than the preload of the pressure regulating spring 14, the valve core 109 of the pressure control device remains stationary, and the oil circuit between the inlet Py and the outlet Pk is cut off; when the pressure at the inlet Py is greater than the preload of the pressure regulating spring 14, the oil pushes the valve core 109 of the pressure control device to slide to the left to overcome the elastic force, and the oil circuit between the inlet Py and the outlet Pk is connected, and the oil can pass through the Py hole 113, the c hole 114, the Pk hole 116, and the outlet Pk in sequence.

[0022] During operation, when the inlet PA is connected to the high-pressure oil circuit, the high-pressure oil enters the PA hole 211 in the pressure differential control device valve seat 201 and the a hole 213 on the pressure differential control device valve body 205 in turn through the inlet PA on the pressure differential control device valve seat 201 to act on the left end of the pressure differential control device valve core 208. The pressure differential control device valve core 208 is subjected to a rightward force and moves to the right. The high-pressure oil flows through the P0 hole 215 on the pressure differential control device valve body 205 to the outlet P0, and then enters the inlet Py through the P0-Py oil circuit 216, and then passes through the Py hole 113 in the pressure control device valve seat 108 and the pressure control device valve. The c hole 114 in the body 110 enters the internal oil chamber and acts on the right end of the pressure control device valve core 109. When the oil pressure is lower than the set pressure (i.e., the preload of the pressure regulating spring 106), the pressure control device valve core 109 abuts against the end face of the second plug 112 under the elastic force of the pressure regulating spring 106, and the high-pressure oil does not communicate with the d hole 115 of the pressure control device valve body 110. The oil in the variable mechanism follower chamber flows back to the oil tank through the Pk hole 116 of the pressure control device valve seat 108, the d hole 115 of the pressure control device valve body 110, and the T hole 117 of the pressure control device valve seat 108. When the oil pressure is higher than the set pressure (i.e., the preload of the pressure regulating spring 106), the valve core 109 of the pressure control device moves to the left under the action of the oil pressure to overcome the elastic force of the pressure regulating spring 106, and the high-pressure oil is connected with the d hole 115 in the valve body 110 of the pressure control device. The oil enters the Pk hole 116 of the valve seat 108 of the pressure control device through the d hole 115, and flows out of the outlet Pk to the follower chamber of the variable mechanism. At this time, the Pk hole 116 and the T hole 117 are disconnected due to the movement isolation of the valve core 109 of the pressure control device. The pressure regulating spring 106 is supported between the adjusting screw 104 and the valve core 109 of the pressure control device. The adjusting screw 104 is screwed into the valve seat 108 of the pressure control device and fixed by the locking nut 105. By screwing the adjusting screw 104, the preload of the pressure regulating spring 106 can be changed, thereby adjusting the opening pressure of the pressure control device a.

[0023] Similarly, when the inlet PB is connected to the high-pressure oil circuit, the high-pressure oil enters the PB hole 212 in the pressure differential control device valve seat 201 and the b hole 214 of the pressure differential control device valve body 205 in turn through the inlet PA on the pressure differential control device valve seat 201, and acts on the right end of the pressure differential control device valve core 208. The pressure differential control device valve core 208 is moved to the left by the left force, and the high-pressure oil flows through the P0 hole 215 of the pressure differential control device valve body 205 to the outlet P0, and then enters the inlet Py through the P0-Py oil circuit 216, and then passes through the Py hole 113 of the pressure control device valve seat 108 and the pressure control device valve body 205. The c hole 114 in 110 enters the internal oil chamber and acts on the right end of the pressure control device valve core 109. When the pressure is lower than the set pressure (i.e., the preload of the pressure regulating spring 106), the pressure control device valve core 109 is pressed against the end face of the second plug 112 under the elastic force of the pressure regulating spring 106. The high-pressure oil does not communicate with the d hole 115 of the pressure control device valve body 110. The oil in the variable mechanism follower chamber flows back to the oil tank through the Pk hole 116 of the pressure control device valve seat 108, the d hole 115 of the pressure control device valve body 110, and the T hole 117 of the pressure control device valve seat 108. When the pressure is higher than the set pressure (i.e., the preload of the pressure regulating spring 106), the valve core 109 of the pressure control device moves to the left under the action of the oil pressure to overcome the elastic force of the pressure regulating spring 106, and the high-pressure oil communicates with the d hole 115 of the valve body 110 of the pressure control device. The oil enters the Pk hole 116 of the valve seat 108 of the pressure control device from the d hole 115, and flows out of the outlet Pk to the follower chamber of the variable mechanism. At this time, due to the movement of the valve core 109 of the pressure control device, the Pk hole 116 and the T hole 117 are isolated and not in communication.

[0024] When the bidirectional variable hydraulic pump (or bidirectional variable hydraulic motor) is not working, the hydraulic pressures at the inlet PA and the inlet PB of the pressure differential control device valve seat 201 are equal, and the valve core 208 of the pressure differential control device does not move under the simultaneous action of the left pressure differential spring 203 and the right pressure differential spring 204, and is in the middle position, and the inlet PA and the inlet PB are disconnected from the outlet P0 and are not in communication. Example 3

[0025] Based on the oil circuit on-off control device of embodiment 2, the embodiment of the present invention further provides a bidirectional variable hydraulic pump, see Figure 3The bidirectional variable hydraulic pump mainly includes a bidirectional hydraulic device 301, a variable mechanism 302, the above-mentioned oil circuit on-off control device 303 and an oil tank 304. The bidirectional hydraulic device 301 is used as a hydraulic pump, and its return oil communicates with the oil tank 304 through the housing return oil circuit 305. The oil in the return chamber (left chamber) of the variable mechanism 302 communicates with the oil tank 304 through the variable mechanism return oil circuit 306, the pressure control device outlet Pk of the oil circuit on-off control device 303 communicates with the follower chamber (right chamber) of the variable mechanism 302 through the control oil circuit 307, the pressure control device outlet T of the oil circuit on-off control device 303 communicates with the oil tank 304 through the return oil circuit 308, the pressure difference control device inlet PA of the oil circuit on-off control device 303 communicates with the high pressure outlet / low pressure inlet A of the bidirectional variable hydraulic pump through the A port inlet oil circuit 309, and the pressure difference control device inlet PB of the oil circuit on-off control device 303 communicates with the low pressure inlet / high pressure outlet B of the bidirectional variable hydraulic pump through the B port inlet oil circuit 310. The direction changing work and specific working process of the bidirectional variable hydraulic pump will not be described in detail. Example 4

[0026] Based on the oil circuit on-off control device of embodiment 2, the embodiment of the present invention further provides a bidirectional variable hydraulic motor, see Figure 4 The bidirectional variable hydraulic motor mainly includes a bidirectional hydraulic device 301, a variable mechanism 302, the above-mentioned oil circuit on-off control device 303 and an oil tank 304. The bidirectional hydraulic device 301 is used as a hydraulic motor, and its return oil communicates with the oil tank 304 through the housing return oil circuit 305. The outlet Pk of the pressure control device of the oil circuit on-off control device 303 communicates with the return chamber (left chamber) of the variable mechanism 302 through the control oil circuit 306, the outlet T of the pressure control device of the oil circuit on-off control device 303 communicates with the oil tank 304 through the return oil circuit 307, the outlet P0 of the pressure difference control device of the oil circuit on-off control device 303 communicates with the follower chamber (right chamber) of the variable mechanism 302 through the pilot control oil circuit 308, the inlet PA of the pressure difference control device of the oil circuit on-off control device 303 communicates with the high pressure outlet / low pressure inlet A of the bidirectional variable hydraulic motor through the A port inlet oil circuit 309, and the inlet PB of the pressure difference control device of the oil circuit on-off control device 303 communicates with the low pressure inlet / high pressure outlet B of the bidirectional variable hydraulic motor through the B port inlet oil circuit 310. The direction changing work and specific working process of the bidirectional variable hydraulic motor will not be described in detail. Example 5

[0027] Based on the bidirectional variable hydraulic pump of embodiment 3, the left self-feeding brake device and the right self-feeding brake device provided by the embodiment of the present invention are shown in FIG. Figure 5 and Figure 6The brake device mainly includes: a wheel 1, a mechanical energy taking mechanism 2, a bidirectional variable hydraulic pump 3 according to an embodiment of the present invention, an oil circuit switching solenoid valve 4, an oil outlet check valve 5, an oil tank 6, an oil filter 7, a safety valve 8, a brake control valve 9 and an actuator 10. The left self-feeding brake device and the right self-feeding brake device correspond to the left and right wheels of the aircraft respectively, and their directions are opposite, and the corresponding bidirectional variable hydraulic pump 3 has the opposite direction, and the inlet and outlet are just interchanged.

[0028] See also Figure 5 When the aircraft moves forward, the input shaft of the two-way variable hydraulic pump 3 of the left self-feeding brake device rotates right, the oil port PB is the high-pressure outlet, the oil port PA is the low-pressure inlet, the upper end of the oil circuit switching solenoid valve 4 is energized, the valve core moves downward, and is in the upper position, the oil port PB is connected to the oil port P, and the oil port PA is connected to the oil port T. The high-pressure oil flows through the high-pressure check valve 5 through the brake control valve 9 and enters the brake actuator 10 to achieve braking; when the aircraft reverses, the oil circuit switching solenoid valve 4 is not energized, the valve core does not move, and is in the middle position, the oil port PB is connected to the oil port PA, and under the blockage of the high-pressure check valve 5, the two-way variable hydraulic pump 3 realizes internal oil circulation and is in a no-load operation state.

[0029] Similarly, see Figure 6 When the aircraft moves forward, the input shaft of the two-way variable hydraulic pump 3 of the right self-feeding brake device rotates left, the oil port PA is the high-pressure outlet, the oil port PB is the low-pressure inlet, the lower end of the oil circuit switching solenoid valve 4 is energized, the valve core moves upward and is in the lower position, the oil port PA is connected to the oil port P, and the oil port PB is connected to the oil port T. The high-pressure oil flows through the high-pressure check valve 5 through the brake control valve 9 and enters the brake actuator 10 to achieve braking. When the aircraft is reversing, the oil circuit switching solenoid valve 4 is not energized, the valve core does not move, and is in the middle position. The oil port PB is connected to the oil port PA. Under the obstruction of the high-pressure check valve 5, the two-way variable hydraulic pump 3 realizes internal oil circulation and is in a no-load operation state.

[0030] Therefore, the oil circuit on-off control method and device of the embodiment of the present invention can be applied to a bidirectional variable hydraulic pump or a bidirectional variable hydraulic motor. When the hydraulic pump or hydraulic motor works in both directions, that is, the high-pressure outlet or high-pressure inlet is interchanged with the low-pressure inlet or low-pressure outlet, the hydraulic pump or hydraulic motor can still realize the function of variable adjustment. That is, as a hydraulic pump, when the input direction changes, the inlet and outlet of the hydraulic pump are interchanged, that is, the outlet becomes the inlet, and the inlet becomes the outlet. As a hydraulic motor, when the input high-pressure oil port changes, the output shaft of the hydraulic motor rotates in the opposite direction. The bidirectional variable output function of the hydraulic pump and hydraulic motor can be realized. The bidirectional variable hydraulic pump of the embodiment of the present invention is used in a self-feeding brake device, and the left and right wheels can be installed with the same type of bidirectional variable hydraulic pump, avoiding the installation of variable hydraulic pumps with specific rotation directions (left-hand or right-hand) for the left and right wheels, which can realize product universalization and reduce development costs and cycles.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling oil circuit on and off, applied to a bidirectional variable hydraulic pump or a bidirectional variable hydraulic motor, characterized in that The following steps are involved: (1) A pressure control device is provided, wherein the outlet Pk is connected to the variable mechanism of the bidirectional variable hydraulic pump or the bidirectional variable hydraulic motor through a control oil circuit, and the outlet T is connected to the oil tank through an oil return oil circuit; (2) a pressure differential control device is provided, wherein the inlet PA and the inlet PB are connected to the oil port A and the oil port B of the bidirectional variable hydraulic pump / motor through the oil inlet oil passage at the A port and the oil inlet oil passage at the B port, respectively, and the outlet P0 is connected to the inlet Py of the pressure control device; (3) The pressure difference control device enables the oil port with higher oil pressure in the oil port B of the oil port A to communicate with the pressure control device. The pressure control device controls the action of the variable mechanism according to the oil pressure value to ensure that the variable mechanism always maintains communication with the high-pressure oil port.

2. The oil circuit on-off control method according to claim 1, characterized in that: The pressure control device comprises a pressure control device valve seat, a pressure control device valve body, a pressure control device valve core, a pressure regulating spring, and the inlet Py, the outlet Pk and the outlet T, wherein: (a) When the pressure of the inlet Py is lower than the preset threshold of the pressure control device, the valve core of the pressure control device is in the disconnected position, so that the inlet Py is disconnected from the outlet Pk, and the outlet Pk is connected to the outlet T, allowing the control oil to flow back to the tank; (b) When the pressure of the inlet Py reaches or exceeds the preset threshold, the valve core of the pressure control device moves to the connection position, so that the inlet Py is connected to the outlet Pk, and the outlet Pk communicates with the follower chamber of the variable mechanism through the control oil circuit, thereby controlling the action of the variable mechanism.

3. The oil circuit on-off control method according to claim 1 or 2, characterized in that: The pressure difference control device comprises a pressure difference control device valve seat, a pressure difference control device valve body, a pressure difference control device valve core, a pressure difference spring, and the inlet PA, the inlet PB and the outlet P0, wherein: (a) the valve core of the pressure difference control device slides in the valve body of the pressure difference control device under the pressure difference between the inlet PA and the inlet PB to change the connection state between the inlet PA and the inlet PB and the outlet P0; (b) when the oil pressure of the inlet PA is higher than the oil pressure of the inlet PB, the valve core of the pressure difference control device connects the inlet PA with the outlet P0; (c) when the oil pressure of the inlet PB is higher than the oil pressure of the inlet PA, the valve core of the pressure difference control device connects the inlet PB with the outlet P0; (d) When the oil pressures of the two inlets are equal or both are lower than a certain threshold, the valve core of the pressure difference control device can be configured to disconnect both inlets from the outlet P0.

4. The oil circuit on-off control method according to claim 3, characterized in that: The preset threshold is adjustable.

5. An oil circuit on-off control device for a bidirectional variable hydraulic pump or a bidirectional variable hydraulic motor, characterized in that include: a pressure difference control device as claimed in claim 3, used to control the communication between the high pressure oil port and the pressure control device according to the oil pressure difference between the oil port A and the oil port B; A pressure control device, as described in claim 2, is used to control the action of the variable mechanism according to the received oil pressure value, ensuring that the variable mechanism is always in communication with the high-pressure oil port.

6. The oil circuit on-off control device according to claim 5, characterized in that: The pressure control device also includes an adjustment mechanism, which is used to adjust the preload force of the pressure adjustment spring, thereby adjusting the preset threshold value.

7. The oil circuit on-off control device according to claim 5, characterized in that: It also includes at least one control valve for adjusting or blocking the control oil circuit and / or the oil return oil circuit under specific conditions to further optimize the accuracy and response speed of the oil circuit on-off control.

8. A bidirectional variable hydraulic pump, characterized in that include: A two-way hydraulic device, used as a hydraulic pump, whose oil return chamber communicates with the oil tank through the shell oil return oil circuit; a variable mechanism for adjusting the displacement of the hydraulic pump, the oil return chamber of which communicates with the oil return chamber of the bidirectional hydraulic device through the variable mechanism oil return oil circuit, and the follower chamber of which communicates with the outlet of the pressure control device of the oil circuit on-off control device as claimed in claim 5 or 6 through the control oil circuit; The oil circuit on-off control device according to claim 5 or 6, used to control the on-off of the oil circuit between the variable mechanism and the bidirectional hydraulic device, ensuring that the variable mechanism always maintains communication with the high-pressure oil port of the bidirectional hydraulic device; An oil tank is used to collect the return oil.

9. A bidirectional variable hydraulic motor, characterized in that include: A two-way hydraulic device, used as a hydraulic motor, whose oil return chamber communicates with the oil tank through the shell oil return oil circuit; A variable mechanism, used to adjust the output torque and torque of the hydraulic motor, whose return oil chamber is communicated with the return oil chamber of the bidirectional hydraulic device through the variable mechanism return oil circuit, and whose follower chamber is connected with the outlet of the pressure control device of the oil circuit on-off control device as claimed in claim 5 or 6 through the control oil circuit; The oil circuit on-off control device according to claim 5 or 6, used to control the on-off of the oil circuit between the variable mechanism and the bidirectional hydraulic device, ensuring that the variable mechanism always maintains communication with the high-pressure oil port of the bidirectional hydraulic device; An oil tank is used to collect the return oil.

10. A self-feeding braking device, characterized in that include: One wheel; a mechanical energy extraction mechanism, connected to the wheel and the bidirectional variable hydraulic pump as claimed in claim 8, for extracting energy from the rotation of the wheel; A bidirectional variable hydraulic pump as claimed in any one of claims 6, for converting mechanical energy into hydraulic energy or vice versa; A control valve, which connects the bidirectional variable hydraulic pump and the actuator and is used for on-off control of the oil circuit between the bidirectional variable hydraulic pump and the actuator; An actuator is used to brake the wheel.

11. The self-powered braking device according to claim 10, characterized in that: The control valve includes: an oil circuit switching solenoid valve, an oil outlet one-way valve, a brake control valve and a safety valve. The bidirectional variable hydraulic pump is connected to the actuator via the oil circuit switching solenoid valve, the oil outlet one-way valve and the brake control valve in sequence.

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