Low-speed and high-torque continuously variable electro-hydraulic drive system

Abstract

The present invention discloses a low-speed high-torque continuously variable electro-hydraulic drive system, which includes a hydraulic motor assembly, a motor housing assembly connected to the hydraulic motor assembly, and a rotor assembly, a stator assembly, a hydraulic pump assembly, a flow distribution block and a rotating cylinder accommodated in the motor housing assembly. The hydraulic pump assembly includes a flow distribution pair and a plunger pair. The flow distribution pair includes the end of the cylinder block and the flow distribution disc. The rotating cylinder is respectively connected to the rotor assembly and the cylinder block of the hydraulic pump assembly. The rotor assembly drives the rotating cylinder and the cylinder block of the hydraulic pump assembly to rotate under the action of electromagnetic force. The hydraulic pump assembly outputs high-pressure oil, which enters the hydraulic motor assembly through the flow distribution block, driving the hydraulic motor assembly to work, realizing the conversion from electrical energy to hydraulic energy and then to mechanical energy. The drive system of the present invention has a high degree of electro-hydraulic integration, and has the characteristics of compact structure, small size, light weight, stepless speed changeability, convenient variable displacement, low noise, high efficiency and energy saving, self-cooling, high power density, high reliability and long service life.

Description

Technical Field

[0001] The present invention belongs to the field of power transmission and control, and particularly relates to a low-speed high-torque continuously variable electro-hydraulic drive system. Background Art

[0002] Low-speed high-torque drive systems have extremely broad application prospects in industrial production, oilfield exploitation, mining machinery, construction machinery, building machinery, coal mining machinery, metallurgical machinery, water conservancy, ocean engineering, port hoisting, ship propulsion, aerospace and other fields. As Figure 1 shown, the current traditional low-speed high-torque drive system includes a mechanical reduction mechanism 1, an electric motor 2, a coupling 3, a cooling device 4, and a load system 7. The electric motor 2 outputs torque at a high speed. Through the transmission chain of the coupling 3 and the mechanical reduction mechanism 1, after the speed is reduced and the torque is increased, the load system 7 is driven to work. The cooling device 4 cools the electric motor to prevent the electric motor 2 from being burned out due to overheating. This structure has the following characteristics: (1) The mechanical reduction mechanism 1, the coupling 3, and the electric motor 2 are arranged axially, which occupies a large space, has a heavy weight, and a low power density, which is particularly disadvantageous for occasions where space and weight are limited; (2) The transmission structure is complex, and there are many energy conversion and power transmission links. It is not easy to ensure the coaxiality during assembly, and mechanical friction losses, vibration and noise are likely to occur; (3) The reduction mechanism has problems such as difficult processing, high price, poor operation reliability, high failure rate, easy occurrence of faults, and high maintenance costs; (4) The overall efficiency of the system is low, and additional cooling and lubrication devices need to be added, increasing the complexity of the equipment, additional energy losses, and construction and operation costs, which does not meet the requirements of economic development for energy conservation and environmental protection; (5) The traditional transmission mode has the problem of "fixed speed, fixed mode", and the production mode is difficult to be adjusted accordingly according to the working conditions.

[0003] Another new type of low-speed high-torque drive system - a low-speed high-torque permanent magnet direct drive system is developing rapidly and is favored by various industries. This system includes a permanent magnet direct drive motor and a load system. The permanent magnet direct drive motor is directly connected to the load system, eliminating the mechanical reduction mechanism 1, which significantly reduces the maintenance workload. However, the low-speed high-torque permanent magnet direct drive system also has the following problems: (1) Since a lower speed is required, the number of poles of the permanent magnet direct drive motor is very large, the number of slots is large, and the requirement for high efficiency forces the motor to increase its outer diameter, and the volume and weight of the motor increase significantly; (2) The permanent magnet direct drive motor uses a large amount of materials, especially rare metals (such as neodymium iron boron, cobalt, etc.), and its cost has been high due to the influence of raw materials; (3) The permanent magnet direct drive motor needs to add additional electronic components for frequency conversion regulation. High-power electronic components have high technical requirements and high prices. Summary of the Invention

[0004] The object of the present invention is to provide a new type of low-speed large-torque drive system with one or more characteristics of compact structure, small volume, light weight, stepless speed change, convenient variable, low noise, high efficiency and energy saving, high power density, high reliability, and long service life, aiming at the problems existing in the current traditional low-speed large-torque drive system.

[0005] The implementation manner of the technical solution of the present invention: A low-speed large-torque stepless speed change electro-hydraulic drive system, characterized in that it includes a hydraulic motor assembly, a motor housing assembly connected to the hydraulic motor assembly, and a rotor assembly, a stator assembly, a hydraulic pump assembly, a flow distribution block, and a rotating cylinder accommodated in the motor housing assembly. The hydraulic pump assembly includes a flow distribution pair and a plunger pair. The flow distribution pair includes the end of the cylinder block and the flow distribution disk. The rotating cylinder is respectively connected to the rotor assembly and the cylinder block. The rotor assembly drives the rotating cylinder and the cylinder block of the hydraulic pump assembly to rotate under the action of electromagnetic force. The hydraulic pump assembly outputs high-pressure oil and enters the hydraulic motor assembly through the flow distribution block, driving the hydraulic motor assembly to work, realizing the conversion from electrical energy to hydraulic energy and then to mechanical energy.

[0006] In the low-speed large-torque stepless speed change electro-hydraulic drive system of the present invention, the hydraulic pump assembly further includes a flow distribution sliding disk pair. The flow distribution sliding disk pair includes an inclined disk and a sliding disk supported on the inclined disk. The inclined disk is supported on the rear end cover of the motor housing assembly. The sliding disk is an integral disk-shaped structure, and a static pressure oil film support is formed between the sliding disk and the inclined disk.

[0007] In the low-speed large-torque stepless speed change electro-hydraulic drive system of the present invention, the flow distribution block is arranged in the housing cavity of the motor housing assembly. The flow distribution pair of the hydraulic pump assembly is supported on one end face of the flow distribution block. The hydraulic motor assembly includes a motor cylinder block and a flow distribution shaft, and the flow distribution shaft abuts against the other end face of the flow distribution block.

[0008] In the low-speed large-torque stepless speed change electro-hydraulic drive system of the present invention, the flow distribution block is provided with a flow distribution block oil inlet opening to the housing cavity, and the flow distribution disk is provided with a low-pressure flow distribution port. The flow distribution block oil inlet is communicated with the low-pressure flow distribution port. During operation, the low-pressure cold oil in the housing cavity enters the plunger holes of the cylinder block from the flow distribution block oil inlet, taking away the heat in the housing cavity to realize self-cooling.

[0009] In the low-speed large-torque stepless speed change electro-hydraulic drive system of the present invention, the flow distribution block is provided with a flow distribution block high-pressure oil groove, and the flow distribution shaft is provided with a flow distribution shaft high-pressure port. The flow distribution block high-pressure oil groove is respectively communicated with the flow distribution shaft high-pressure port and the high-pressure flow distribution port on the flow distribution disk. During operation, the high-pressure oil flowing out of the cylinder block plunger holes of the hydraulic pump assembly enters the flow distribution shaft high-pressure port through the flow distribution block high-pressure oil groove, driving the hydraulic motor assembly to rotate and drive the load to work.

[0010] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a flow distribution block oil outlet passage is provided on the flow distribution block, and the flow distribution block oil outlet passage opens to the housing cavity of the motor housing assembly, so that the low-pressure hydraulic fluid after the action of the hydraulic motor assembly is discharged into the housing cavity.

[0011] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a low-pressure oil distribution window is provided on the swash plate, the low-pressure oil distribution window is communicated with the oil inlet provided on the rear end cover, and an oil passage leading to the low-pressure oil distribution window of the swash plate and an oil passage leading to the housing cavity through the oil inlet fork are provided on the oil inlet of the rear end cover. During operation, the low-pressure hydraulic fluid enters the plunger holes of the cylinder block through the low-pressure oil distribution port of the flow distribution disk and the low-pressure oil distribution window of the swash plate from the flow distribution block oil inlet, realizing oil suction.

[0012] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a check valve is provided on the flow distribution block, the check valve is communicated with the high-pressure oil tank of the flow distribution block, and the check valve only allows oil to enter the high-pressure oil tank of the flow distribution block unidirectionally from the housing cavity. When the hydraulic motor assembly changes to the pump working condition, the check valve plays a role in supplementary oil supply.

[0013] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a high-pressure oil tank and a low-pressure oil tank are provided on the flow distribution block, a high-pressure port and a low-pressure port are provided on the flow distribution shaft, the high-pressure oil tank of the flow distribution block is respectively communicated with the high-pressure port of the flow distribution shaft and the high-pressure oil distribution port on the flow distribution disk, and the low-pressure oil tank of the flow distribution block is respectively communicated with the low-pressure port of the flow distribution shaft and the low-pressure oil distribution port on the flow distribution disk. During operation, the high-pressure hydraulic fluid flowing out of the plunger holes of the cylinder block of the hydraulic pump assembly enters the high-pressure port of the flow distribution shaft through the high-pressure oil tank of the flow distribution block, and the low-pressure hydraulic fluid after the action of the hydraulic motor assembly returns to the plunger holes of the cylinder block of the hydraulic pump assembly through the low-pressure oil tank of the flow distribution block.

[0014] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, the supporting surface of the swash plate opposite to the rear end cover has a cylindrical sliding arc surface formed as a cylinder, and a groove-shaped low-pressure port and a groove-shaped high-pressure port configured as a groove are provided on the cylindrical sliding arc surface of the swash plate. The groove-shaped low-pressure port is communicated with the oil inlet, and the groove-shaped high-pressure port is communicated with the high-pressure oil hole provided on the rear end cover.

[0015] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a valve group is connected to the rear end cover, the oil inlet of the valve group is communicated with the high-pressure oil hole, the valve group is used for controlling the pressure, flow rate and direction of the hydraulic pump assembly, and the valve group includes one or a combination of a pressure valve, a flow valve and a direction valve.

[0016] The low-speed high-torque continuously variable electro-hydraulic drive system of the present invention is provided with an accumulator on the electro-hydraulic drive system. The accumulator includes a high-pressure accumulator and / or a low-pressure accumulator. The accumulator is connected to the valve group, and the accumulator has one or more functions of assisting in starting, stabilizing pressure, supplementing leaked oil, and providing an auxiliary control oil source.

[0017] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, a variable mechanism for controlling the displacement of the hydraulic pump assembly is provided on the motor housing assembly. The variable mechanism is set as a swash plate angle control type variable structure. The variable mechanism includes a variable piston, a control valve, and a variable spring. The variable piston drives the swash plate to rotate.

[0018] In the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention, the outer peripheral surface of the drum is connected to the rotor assembly. An inwardly extending connecting portion is provided inside the drum. A plurality of oil passing holes are circumferentially provided in the connecting portion. The oil passing holes communicate with the two-side housing cavities of the motor housing assembly, enabling the low-pressure oil to pass through smoothly. The connecting portion of the drum is cooperatively connected with the cylinder block.

[0019] The hydraulic pump assembly of the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention is of a shaft-supported structure. It further includes a main shaft, a first bearing, and a second bearing. The axis of the main shaft coincides with the axis of the cylinder block. One end of the main shaft penetrates through the flow distribution pair to the flow distribution block and is supported on the first bearing, and the other end penetrates through the flow distribution slide pair to the rear end cover of the motor housing assembly and is supported on the second bearing. The cylinder block is supported on the main shaft and is synchronously rotated with the main shaft through a key connection. The plunger pair includes the plunger hole wall of the cylinder block and the plunger. The plunger reciprocates in the plunger cavity of the cylinder block to achieve oil suction and discharge work.

[0020] The hydraulic pump assembly of the low-speed high-torque continuously variable electro-hydraulic drive system of the present invention is of a drum-supported structure. It further includes a fourth bearing and / or a fifth bearing. The fourth bearing and the fifth bearing are respectively clamped between the drum and the motor housing assembly, or the fourth bearing is supported between the drum and the flow distribution block. The rotor assembly and the hydraulic pump assembly are supported on the fourth bearing and / or the fifth bearing through the drum and achieve synchronous rotation. The plunger pair includes the plunger hole wall of the cylinder block and the plunger. The plunger reciprocates in the plunger cavity of the cylinder block to achieve oil suction and discharge work.

[0021] Based on the above technical solutions, the beneficial effects of the present invention are:

[0022] (1) The present invention significantly reduces the weight and volume of the low-speed high-torque drive system, and improves the overall power density of the system. In the present invention, devices such as hydraulic pumps, hydraulic motors, motors, and controls are highly integrated, and the mechanical reduction mechanism in the traditional low-speed high-torque drive system is eliminated, giving full play to the high power-to-weight ratio characteristic of hydraulic transmission, so that the overall volume and weight of the power drive system are significantly reduced. Therefore, the low-speed high-torque drive system of the present invention has outstanding high power-to-weight ratio advantages, and is particularly suitable for fields with strict requirements for space and weight, such as mobile machinery, ship propulsion systems, and aerospace fields.

[0023] (2) The present invention is easy to achieve stepless speed change control. In the present invention, devices such as hydraulic pumps, hydraulic motors, motors, and variable controls are highly integrated, and stepless speed regulation can be achieved by adjusting the swash plate angle and other methods. The speed regulation is a soft regulation, which can better adapt to the speed change control under different working conditions, eliminating complex and expensive electronic components such as frequency converters, reducing power loss, and lowering costs.

[0024] (3) The present invention has high transmission efficiency. In the present invention, devices such as hydraulic pumps, hydraulic motors, motors, and variable controls are highly integrated, eliminating components such as the mechanical reduction mechanism, drive shaft, and coupling in the transmission link, eliminating additional electronic components such as frequency converters, and eliminating components such as cooling devices. Therefore, the additional energy losses in the energy conversion and power transmission links, as well as the cooling devices and electronic components, are reduced. At the same time, the mechanical friction loss is also significantly reduced, making the overall efficiency of the drive system higher and the operation more reliable.

[0025] (3) The present invention significantly reduces noise and vibration. The main sources of noise and vibration in traditional power drive systems are: mechanical reduction mechanisms, motors, mechanical vibrations and noises generated by the coaxiality error of coupling connections, and noises and vibrations generated by motor air cooling devices; in the present invention, devices such as hydraulic pumps, hydraulic motors, motors, and variable controls are highly integrated, the motor assembly and the hydraulic pump assembly are coaxial and co-shell, eliminating the coupling, air cooling device, and connecting pipeline between the hydraulic pump and the hydraulic motor, and the noise is significantly reduced.

[0026] (4) The present invention has self-cooling and is easy to dissipate heat. Traditional motors and mechanical reduction mechanisms have energy dissipation during operation, which is finally dissipated into the external environment in the form of heat, and additional cooling devices or lubrication devices are required. In the present invention, devices such as hydraulic pumps, hydraulic motors, motors, and variable controls are highly integrated, and the low-pressure cold oil in the shell cavity flows through the three friction pairs of the motor stator assembly, rotor assembly, and hydraulic pump assembly, and brings the heat generated by them into the hydraulic system to achieve self-cooling.

[0027] (5) The present invention has a long service life and high reliability. In the electro-hydraulic drive system of the present invention, all components are highly integrated, and each mechanical component is highly integrated, simplifying the structural complexity; the sliding disk in the flow distribution sliding disk pair is an integral structure, and the plunger in the plunger pair is a conical structure. The unique designs of both significantly reduce the lateral force exerted by the plunger on the cylinder block, significantly improve the working conditions of the three major friction pairs, improve the oil film stability, and enable the hydraulic rotor part to have higher speed, higher pressure, larger flow rate, and longer service life.

[0028] (6) The present invention can be easily designed into a closed circuit, which is beneficial to reducing the volume of the fuel tank, facilitating the setting of energy storage devices, facilitating the forward and reverse direction transformation, and improving the operating efficiency of the system at the same time.

[0029] (7) The present invention reduces external leakage. The electro-hydraulic of the drive system is highly integrated, avoiding the corrosion and wear of the seals at multiple pipeline connection parts and the shaft extension of the hydraulic pump under long-term working conditions, which may cause external leakage, resulting in environmental pollution and inconvenience in management and maintenance, and is especially suitable for occasions with strict environmental requirements.

[0030] (8) The present invention can achieve series-parallel connection of multiple machines. Since the devices such as hydraulic pumps, hydraulic motors, motors, and controls in the present invention are highly integrated into one body, with large power, small volume, and light weight, when ultra-high power is required, multiple electro-hydraulic drive systems can be connected in series-parallel to achieve a doubling of the output power. Brief Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of a traditional low-speed high-torque drive system.

[0032] Figure 2 is a schematic structural diagram of the electro-hydraulic drive system of the present invention.

[0033] Figure 3 is an embodiment of an open electro-hydraulic drive system in the present invention.

[0034] Figure 4 is Figure 3 the A-A sectional view in

[0035] Figure 5 is the internal liquid flow diagram of the electro-hydraulic drive system in the present invention.

[0036] Figure 6 is the plan view of one end of the sliding disk in the present invention.

[0037] Figure 7 is Figure 6 the B-B sectional view of the sliding disk structure in

[0038] Figure 8 is the plan view of the other end of the sliding disk in the present invention.

[0039] Figure 9 This is a plan view of one support surface of the swash plate in the present invention.

[0040] Figure 10 This is a plan view of the other support surface of the swash plate in the present invention.

[0041] Figure 11 This is a plan view of one support surface of the valve plate in the present invention

[0042] Figure 12 This is a plan view of one end of the cylinder block in the present invention.

[0043] Figure 13 This is a sectional view of the rotating cylinder along the axis in the present invention.

[0044] Figure 14 This is a plan view of one side of the rotating cylinder in the present invention.

[0045] Figure 15 This is a sectional view of the valve block along the axis in the present invention.

[0046] Figure 16 It is Figure 15 the C-C sectional view in

[0047] Figure 17 This is a sectional view of the valve block along the axis at another angle in the present invention.

[0048] Figure 18 This is an embodiment of the electro-hydraulic drive system with a one-way valve in the present invention.

[0049] Figure 19 This is an embodiment of the closed electro-hydraulic drive system in the present invention.

[0050] Figure 20 This is an embodiment of the electro-hydraulic drive system with a valve group and an accumulator in the present invention.

[0051] Figure 21 This is in the present invention Figure 20 a plan view of one support surface of the swash plate of the embodiment.

[0052] Figure 22 This is in the present invention Figure 20 a plan view of the other support surface of the swash plate of the embodiment.

[0053] Figure 23 This is an embodiment of the rotating cylinder supported electro-hydraulic drive system in the present invention.

[0054] Figure 24 This is another embodiment of the rotating cylinder supported electro-hydraulic drive system in the present invention.

[0055] Figure 25This is another embodiment of the permanent magnet rotor assembly in the present invention.

[0056] Markings in the figure: 1 is a mechanical reduction mechanism, 2 is an electric motor, 3 is a coupling, 4 is a cooling device, 5 is an electro-hydraulic drive system, 6 is an outlet box, 7 is a load system, 8 is a stator assembly, 8a is a stator core, 8b is a stator winding, 9 is a rotor assembly, 9a is a rotor core, 9b is a rotor winding, 9c is a permanent magnet, 9d is an end ring, 10 is a main shaft, 10C is the axis of the main shaft, 11 is a rotating cylinder, 12 is a connecting part, 13 is an oil passage hole, 14 is a connecting key, 15 is a convex part, 16 is a first stop block, 17 is a second stop block, 21 is a first bearing, 22 is a second bearing, 23 is a third bearing, 24 is a fourth bearing, 25 is a fifth bearing, 31 is a motor housing, 33 is a rear end cover, 33a is an oil inlet, 33c is an oil inlet fork, 34 is a housing cavity, 35 is a flow distribution block, 36 is a flow distribution block oil inlet, 37 is a high-pressure oil groove of the flow distribution block, 38 is an oil outlet passage of the flow distribution block, 39 is a low-pressure oil groove of the flow distribution block, 40 is a swash plate, 41a is a swash plate support stop part, 42 is a flow distribution oil groove, 43 is a low-pressure flow distribution window, 44 is a high-pressure flow distribution window, 45 is a cylindrical sliding arc surface, 46 is a groove-shaped low-pressure port, 47 is a groove-shaped high-pressure port, 50 is a sliding disk, 50C is the axis of the sliding disk, 51 is a static pressure support surface of the sliding disk, 52 is a convex table surface of the sliding disk, 53 is a waist-shaped hole of the sliding disk, 54 is an outer sealing part of the sliding disk, 55 is an inner sealing part of the sliding disk, 56 is an interval sealing part of the sliding disk, 58 is a plunger ball socket, 60 is a pressure plate, 70 is a plunger, 71 is a plunger ball head, 72 is a central hole of the plunger, 73 is a tapered rod part, 74 is a plunger part, 80 is a cylinder block, 81 is a plunger hole, 82 is a main shaft assembly hole, 83 is a static pressure support surface of the cylinder block, 84 is an oil passage hole, 85 is a waist-shaped hole of the cylinder block, 90 is a flow distribution disk, 91 is a support surface, 92 is a low-pressure flow distribution port, 93 is a high-pressure flow distribution port, 100 is a central spring, 101 is a retaining ring, 102 is a ball hinge, 110 is a variable mechanism, 111 is a variable piston, 112 is a control valve, 113 is a variable spring, 120 is a hydraulic motor assembly, 121 is an output shaft, 122 is a motor cylinder block, 123 is a motor plunger, 124 is a cross beam, 125 is a roller, 126 is a flow distribution shaft, 126a is a low-pressure port of the flow distribution shaft, 126b is a high-pressure port of the flow distribution shaft, 127 is a motor housing, 130 is a valve group, 131 is a high-pressure oil hole, 132 is a high-pressure accumulator, 133 is a low-pressure accumulator, 141 is a circlip, 150 is a check valve, 160 is a make-up oil pump. Detailed implementation manners

[0057] The present invention will be described in detail below with reference to the accompanying drawings.

[0058] Although the present invention admits of various forms of embodiments, only some specific forms, such as examples of the present invention, are disclosed in this specification and the accompanying drawings. However, the present invention is not intended to be limited to the described embodiments. The scope of the present invention is given in the appended claims.

[0059] For convenience of description, the embodiments of the present invention are shown in a typical orientation, which is such that when the central axis of the main shaft of the electro-hydraulic drive system 5 is horizontally stationary, with the side of the hydraulic motor assembly being on the left and the rear end cover being on the right, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "horizontal", "bottom", "inner", "outer", etc. used in the description are all referenced to this position. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, as well as a specific orientation structure and operation. It should be understood that the present invention can be manufactured, stored, transported, used, and sold in an orientation different from the described position.

[0060] Embodiment 1:

[0061] As Figures 2 to 5 shown, it is a preferred embodiment of the electro-hydraulic drive system 5 of the present invention. In the shown preferred embodiment, the electro-hydraulic drive system 5 is of a shaft-supported structure and an open system, and includes a hydraulic motor assembly, a motor housing assembly connected to the hydraulic motor assembly, and a rotor assembly 9, a stator assembly 8, a hydraulic pump assembly, a flow distribution block 35, a rotating cylinder 11, a main shaft 10, a first bearing 21, and a second bearing 22 accommodated in the motor housing assembly. The hydraulic pump assembly includes a flow distribution sliding disc pair, a flow distribution pair, and a plunger pair. The flow distribution pair includes the end of a cylinder block 80 and a flow distribution disc 90. The cylinder block 80 abuts against the flow distribution disc 90, and a static pressure oil film support is formed therebetween. The rotating cylinder 11 is respectively connected to the rotor assembly 9 and the cylinder block 80 of the hydraulic pump assembly. The rotor assembly 9 drives the rotating cylinder 11 and the cylinder block 80 of the hydraulic pump assembly to rotate synchronously under the action of electromagnetic force. The hydraulic pump assembly outputs high-pressure oil and enters the hydraulic motor assembly through the flow distribution block 35, driving the hydraulic motor assembly to work, realizing the conversion from electrical energy to hydraulic energy and then to mechanical energy.

[0062] Specifically, the flow distribution sliding disk pair includes a swash plate 40 and a sliding disk 50 supported on the swash plate 40. The sliding disk 50 is an integral structure, and a static pressure oil film support is formed between the sliding disk 50 and the swash plate 40. The axis of the main shaft 10 coincides with the axis of the cylinder block 80. One end of the main shaft 10 penetrates through the flow distribution pair to the flow distribution block 35 and is supported on the first bearing 21, and the other end penetrates through the flow distribution sliding disk pair to the rear end cover 33 of the housing assembly and is supported on the second bearing 22. The cylinder block 80 is supported on the main shaft 10 and is connected to the main shaft 10 by a key to achieve synchronous rotation. The plunger pair includes the plunger hole wall of the cylinder block 80 and the plunger 70. Preferably, the plunger 70 is a conical structure with a large central hole in the center. The plunger 70 reciprocates in the plunger cavity of the cylinder block 80 to achieve oil suction and discharge work.

[0063] Specifically, the motor includes, but is not limited to, an induction asynchronous motor, a permanent magnet DC motor, a permanent magnet synchronous motor, etc. Preferably, the motor is an induction asynchronous motor, including existing squirrel-cage asynchronous motors and wound-rotor asynchronous motors. The motor assembly includes a stator assembly 8 and a rotor assembly 9. The stator assembly 8 includes components such as a stator core 8a and a stator winding 8b. Among them, the stator core 8a is a part of the magnetic circuit and circuit of the motor, which is punched and laminated by thin silicon steel sheets coated with insulating paint on the surface. Its outer peripheral surface is fixedly connected to the motor housing 31 of the housing assembly. A plurality of notches (not shown) are provided on the inner peripheral surface of the stator core 8a. The stator winding 8b is embedded in the notches of the stator core 8a. The stator winding 8b is wound by insulated copper wire or insulated aluminum wire. The lead-out ends of the stator winding 8b are led to an outlet box 6 provided on the motor housing 31. The rotor assembly 9 of the motor includes components such as a rotor core 9a and a rotor winding 9b. Among them, the rotor core 9a is also punched and laminated by thin silicon steel sheets coated with insulating paint on the surface. Its inner peripheral surface is fixedly connected to the rotating cylinder 11. The two side surfaces of the rotor core 9a are abutted against the protruding part 15 of the rotating cylinder 11 by a first stop block 16 to limit the axial displacement of the rotor core 9a and the rotating cylinder 11. A plurality of notches (not shown) are provided on the outer peripheral surface of the rotor core 9a. The rotor winding 9b is embedded in the notches of the rotor core 9a. The rotor winding 9b includes, but is not limited to, a squirrel-cage structure and a wound-rotor structure rotor winding. Among them, the squirrel-cage structure is to insert copper bars or aluminum bars into the slots on the rotor core 9a as conducting bars and connect them with copper rings or aluminum rings at both ends to form a cage-like structure. The wound-rotor structure is to provide a coil winding on the rotor core 9a.

[0064] Wherein, a certain air gap is maintained between the stator assembly 8 and the rotor assembly 9 of the motor to ensure reasonable power factor and starting performance during motor operation. Alternatively, the air gap can also be filled with low-pressure cold oil in the housing cavity 34 of the housing assembly to dissipate the heat of the stator assembly 8 and the rotor assembly 9 of the motor.

[0065] Specifically, the hydraulic motor assembly 120 is used to convert hydraulic energy into mechanical energy, and includes but is not limited to radial piston motors and axial piston motors. Preferably, the hydraulic motor assembly 120 is a radial piston motor, including a crankshaft-type radial piston motor and an internal curve-type radial piston motor. Further preferably, the hydraulic motor assembly 120 is a crossbeam-force transmission internal curve piston motor, such as Figure 3 As shown, the hydraulic motor assembly 120 includes a motor housing 127, an output shaft 121 connected to the load, a motor cylinder block 122 connected to the output shaft 121, a radially displaced motor plunger 123, a crossbeam 124 in contact with the motor plunger 123, a roller 125, and a distribution shaft 126. The motor plunger 123 transmits force to the crossbeam 124. The crossbeam 124 is supported on the roller 125 and can slide in the radial groove of the motor cylinder block 122. The top of the motor plunger 123 has a configuration of a spherical surface or a conical surface and is in contact with the crossbeam 124 to transmit hydraulic pressure. The motor plunger 123 can be arranged in a multi-row structure to increase the displacement, preferably 2-3 rows. The distribution shaft 126 includes a distribution shaft low-pressure port 126a and a distribution shaft high-pressure port 126b.

[0066] Predictably, the load system 7 connected to the hydraulic motor includes but is not limited to open mills, internal mixers, extruders in industrial production machinery, crushers, coal mills, scraper conveyors, bucket wheel machines and various belt conveying equipment in mining machinery, drilling rigs for oilfield exploitation, ship propulsion systems, helicopter blades, port lifting and winching equipment, etc.

[0067] Specifically, the flow distribution sliding disc pair includes a sliding disc 50 and an inclined disc 40 supported on the rear end cover 33. The sliding static pressure supporting surface 51 of the sliding disc 50 is supported on the inclined disc 40 and is in close fit with the supporting surface of the inclined disc 40. A plurality of sliding disc waist-shaped holes 53 are provided at one end of the sliding disc 50, and a plurality of plunger ball sockets 58 are provided on the other end surface of the sliding disc 50. The sliding disc waist-shaped holes 53 on the sliding disc 50 penetrate through to the plunger ball sockets 58. A low-pressure flow distribution window 43 and a flow distribution oil groove 42 are provided on the inclined disc 40. The low-pressure flow distribution window 43 is communicated with the oil inlet 33a provided on the rear end cover 33 through the flow distribution oil groove 42. More specifically, the supporting surface of the inclined disc 40 facing the rear end cover 33 has a cylindrical sliding arc surface 45 formed in a cylindrical shape, and a groove-shaped low-pressure port 46 configured in a groove shape is provided on the cylindrical sliding arc surface 45 of the inclined disc 40. The groove-shaped low-pressure ports 46 are respectively communicated with the low-pressure flow distribution window 43 and the oil inlet 33a.

[0068] Specifically, the plunger pair includes a plunger 70 and the cylinder block hole wall. The plunger 70 is of a conical structure, and a large-diameter plunger central hole 72 for oil inlet and outlet and communicating the plunger ball socket 58 and the plunger hole 81 is provided on the plunger.

[0069] Specifically, the flow distribution pair includes the end of the cylinder block 80 and the flow distribution disc 90. The end surface of the end of the cylinder block 80 facing the flow distribution disc 90 is provided with a cylinder block static pressure supporting surface 83. The cylinder block static pressure supporting surface 83 is supported on the flow distribution disc 90 and is in sliding fit with the supporting surface 91 of the flow distribution disc 90. A low-pressure flow distribution port 92 and a high-pressure flow distribution port 93 are provided on the flow distribution disc 90, as Figure 11 shown.

[0070] Specifically, the motor housing assembly includes a motor housing 31 and a rear end cover 33 connected to the motor housing 31. The motor housing 31 and the rear end cover 33 enclose a housing cavity 34 for accommodating a rotor assembly, a stator assembly, and a hydraulic pump assembly. The rear end cover 33 is used to close one end opening of the motor housing 31, and an oil inlet 33a is provided on the rear end cover 33.

[0071] Further, an oil circuit leading to the low-pressure oil distribution window 43 on the inclined disc 40 and an oil circuit leading to the inside of the housing cavity 34 through the oil inlet fork 33c are provided on the oil inlet 33a of the rear end cover 33. During operation, low-pressure oil enters the plunger holes 81 of the cylinder block 80 through the low-pressure flow distribution port 92 of the flow distribution disc 90 and the low-pressure oil distribution window 43 of the inclined disc 40 in a dual path from the oil inlet of the flow distribution block 36 to achieve oil suction.

[0072] Specifically, a flow distribution block 35 is provided in the housing cavity 34 of the motor housing assembly. The flow distribution pair of the hydraulic pump assembly is supported on one side end surface of the flow distribution block 35, and the flow distribution shaft 126 of the hydraulic motor assembly abuts against the other side end surface of the flow distribution block 35.

[0073] Further, as shown in Figure 15 and 16 , a flow distribution block oil inlet 36 opening to the housing cavity 34 is provided on the flow distribution block 35, a low-pressure flow distribution port 92 is provided on the flow distribution disk 90, and the flow distribution block oil inlet 36 is communicated with the low-pressure flow distribution port 92. During operation, the low-pressure cold oil in the housing cavity 34 enters the plunger hole 81 of the cylinder block 80 from the flow distribution block oil inlet 36, taking away the heat of the housing cavity 34 to achieve self-cooling.

[0074] Further, a high-pressure oil groove 37 is provided on the flow distribution block 35. The high-pressure oil groove 37 of the flow distribution block is communicated with the high-pressure port 126b of the flow distribution shaft and the high-pressure flow distribution port 93 on the flow distribution disk 90 respectively. During operation, the high-pressure oil flowing out of the plunger hole 81 of the cylinder block of the hydraulic pump assembly enters the high-pressure port 126b of the flow distribution shaft through the high-pressure oil groove 37 of the flow distribution block, driving the rotation of the hydraulic motor assembly and driving the load to work.

[0075] Further, as shown in Figure 17 , an oil outlet passage 38 is provided on the flow distribution block 35. The oil outlet passage 38 of the flow distribution block opens to the housing cavity 34 of the motor housing assembly, so that the low-pressure oil after the action of the hydraulic motor assembly is discharged into the housing cavity 34.

[0076] Further, as shown in Figure 18 , a check valve 150 is provided on the flow distribution block 35. The check valve 150 is communicated with the high-pressure oil groove 37 of the flow distribution block. The check valve 150 only allows oil to enter unidirectionally from the housing cavity 34 to the high-pressure oil groove 37 of the flow distribution block, and does not allow oil to be discharged from the high-pressure oil groove 37 of the flow distribution block to the housing cavity 34. When the hydraulic motor assembly 120 is in the pump working condition, the check valve 150 plays a role in oil replenishment.

[0077] Specifically, the flow distribution block 35 may be a part of the flow distribution shaft 126 extending into the housing cavity 34, that is, the flow distribution block 35 and the flow distribution shaft 126 are of an integral structure; or the flow distribution block 35 may be a part of the motor housing 127 in the motor assembly extending into the housing cavity 34, that is, the flow distribution block 35 and the motor housing 127 are of an integral structure.

[0078] As shown in Figure 5As shown in the figure, it is the internal oil flow diagram of the electro-hydraulic drive system 5. Low-pressure cold oil enters the plunger holes 81 of the hydraulic pump assembly in two paths from the oil inlet 33a of the rear end cover 33 in the motor housing assembly. The first path passes through the low-pressure oil distribution window 43 on the swash plate 40, the waist-shaped hole 53 of the sliding plate, and the large central hole 72 of the conical plunger to enter the cylinder block plunger hole 81. The second path leads to the housing cavity 34 through the oil inlet fork 33c, and enters the cylinder block plunger hole 81 through the oil inlet 36 of the distribution block and the low-pressure oil distribution port 92. The low-pressure cold oil in the second path flows through the three major friction pairs of the stator assembly, rotor assembly, and hydraulic pump assembly of the motor assembly.

[0079] Based on the above structural design, the remarkable effects are as follows: When the low-pressure cold oil entering from the oil inlet fork 33c of the rear end cover 33 flows through the housing cavity 34, the various friction pairs placed in the housing cavity 34 and the rotor assembly and stator assembly components of the motor assembly are immersed in the low-temperature oil, and the heat generated by the three major friction pairs of the stator assembly, rotor assembly, and hydraulic motor assembly of the motor assembly is taken away and enters the hydraulic system.

[0080] From the above analysis, it can be known that this structure has the characteristics of self-cooling and easy heat dissipation, which are specifically manifested in: on the one hand, it can keep the key components such as the motor stator, rotor, and three major hydraulic friction pairs always immersed in the low-temperature oil, preventing the motor stator and rotor from burning out and the oil film stability of the three major friction pairs from being damaged; on the other hand, due to the lack of the liquid resistance effect of the oil pipeline, the self-priming ability can be greatly improved.

[0081] At the same time, this structure also has the characteristics of small volume, light weight, high power density, high efficiency, and low noise. As Figure 1 shown, it is a traditional low-speed high-torque drive system, which consists of a mechanical reduction mechanism 1, a motor 2, a coupling 3, etc., arranged axially as independent components, with a long axial length, large occupied space, and heavy weight. Figure 2 This is the electro-hydraulic drive system in the present invention. It cancels the reduction mechanism 1 in the traditional drive system, gives full play to the high power-to-weight ratio characteristics of hydraulic transmission, and greatly reduces the overall volume and total weight of the drive system, which is irreplaceable by other drive systems; the motor, hydraulic motor assembly, and hydraulic pump assembly are highly integrated into one body, eliminating connecting components such as couplings and cooling devices, reducing the energy conversion and power transmission links and the additional energy loss of the cooling device; the motor and hydraulic pump are coaxial and co-shell, canceling the coupling and cooling device, and the noise is significantly reduced.

[0082] Specifically, as Figure 13 and 14As shown, the outer peripheral surface of the rotating cylinder 11 is connected to the rotor assembly 9 of the motor assembly. An inwardly extending connecting portion 12 is provided inside the rotating cylinder 11. A plurality of oil passing holes 13 are circumferentially provided in the connecting portion 12. The oil passing holes 13 communicate with the housing cavities 34 on both sides, enabling the low-pressure hydraulic fluid to pass through smoothly. A connecting key 14 that is circumferentially matched with the outer periphery of the cylinder block 80 is provided inside the connecting portion 12 in the circumferential direction. Alternatively, the connection between the connecting portion of the rotating cylinder and the cylinder block may also include, but is not limited to, interference fit connection, bolt connection, etc.

[0083] Further, a restraining device for restricting axial movement is provided on the rotating cylinder 11. The restraining device includes protruding portions 15 that protrude outward on both sides of the rotating cylinder 11 for restricting the axial displacement of the motor rotor, and a first stopper 16 clamped between the motor rotor and the protruding portions 15. The restraining device further includes a second stopper 17 provided on the outer circumference of the cylinder block 80 for restricting the axial displacement of the rotating cylinder 11. The second stopper 17 is connected to the connecting portion 12 of the rotating cylinder 11.

[0084] Further, the electro-hydraulic drive system 5 further includes a variable mechanism 110. The variable mechanism is used to adjust the displacement of the hydraulic pump assembly to achieve stepless speed control. The variable mechanism is a swash plate angle control type variable structure. The swash plate angle control type variable mechanism includes a variable piston 111, a control valve 112, and a variable spring 113. The control valve 112 is connected to the rear end cover 33. A plurality of fluid flow channels are provided inside the control valve 112. The control valve 112 controls the movement of the variable piston 111 by controlling the oil fluid entering the variable piston 111 to achieve a change in the angle of the swash plate 40. The control valve 112 can be set with a variety of variable control methods according to the working condition parameters. The variable spring 113 functions to reset.

[0085] More specifically, a plurality of plunger ball sockets 58 are provided at the circumferential position of the end face of the swash plate 50 facing the cylinder block 80. As shown in FIGS. Figure 6 、 7 and 8, the plunger ball sockets 58 form concave portions with an opening approximately in a hemispherical shape on the end face of the swash plate 50. The plunger ball sockets 58 support the plunger ball heads 71 in a state of being evenly spaced in a common circumference centered on the swash plate axis 50C. After the plungers 70 are installed in the plunger ball sockets 58, they are fixed to the end face of the swash plate 50 by a pressing plate 60, restricting the movement of the plungers 70 away from the end face of the swash plate 50. Specifically, the method for fixing the plungers 70 to the end face of the swash plate 50 is not limited to using a pressing plate. For example, a clamping device (not shown) with form locking may be provided on the swash plate 50, and the clamping device can fix the plunger ball heads 71 by wrapping more than 180 degrees.

[0086] Among them, a swashplate static pressure support surface 51 is provided on the end surface of the swashplate 50 facing the inclined disk 40. As Figure 7 shown, the swashplate axis 50C forms a certain angle with the main shaft axis. The swashplate static pressure support surface 51 is supported on the inclined disk 40 and always maintains a sliding fit with the inclined disk 40. A plurality of swashplate waist-shaped holes 53 configured as waist-shaped are provided on the swashplate static pressure support surface 51. Preferably, the swashplate waist-shaped holes 53 are evenly distributed on the swashplate static pressure support surface 51 centered on the swashplate axis 50C. The swashplate waist-shaped holes 53 communicate with the plunger ball socket 58.

[0087] Furthermore, a protruding swashplate convex surface 52 extending from the swashplate axis 50C toward the inclined disk 40 is provided on the end surface of the swashplate 50 facing the inclined disk 40. The swashplate convex surface 52 is composed of a region surrounded by an inner diameter R1 and an outer diameter R2. The swashplate convex surface 52 and the support surface of the inclined disk 40 are in sliding contact with each other. A plurality of swashplate waist-shaped holes 53 are provided at positions corresponding to the plunger ball socket 58 on the swashplate convex surface 52. Preferably, the swashplate waist-shaped holes 53 are evenly spaced in a common circumference centered on the swashplate axis 50C on the swashplate convex surface 52.

[0088] Among them, an effective static pressure oil film support is formed between the swashplate convex surface 52 and the support surface of the inclined disk 40. A sealing portion for sealing the action of the oil is provided on the swashplate convex surface 52. The sealing portion is provided on the inner and outer circumferences of the swashplate waist-shaped holes 53 in a state of surrounding the swashplate waist-shaped holes 53. The sealing portion includes a swashplate inner sealing portion 55, a swashplate outer sealing portion 54 distributed radially inside and outside the swashplate waist-shaped holes 53, and a swashplate interval sealing portion 56 distributed between adjacent swashplate waist-shaped holes 53. The swashplate inner sealing portion 55 is a region surrounded by the inner edge of the swashplate waist-shaped hole 53 and the inner diameter R1 of the swashplate convex surface 52. The swashplate outer sealing portion 54 is a region surrounded by the outer edge of the swashplate waist-shaped hole 53 and the outer diameter R2 of the swashplate convex surface 52. The swashplate interval sealing portion 56 is an interval convex surface region between adjacent swashplate waist-shaped holes 53. A certain reasonable gap is always maintained between the sealing portion of the swashplate convex surface 52 and the support surface of the inclined disk 40 so that the oil film leakage is at a reasonable level.

[0089] As Figure 12As shown, the cylinder block 80 has a columnar configuration with a circular radial cross-section and is accommodated in the housing cavity 34 of the housing assembly. The cylinder block 80 has a plurality of plunger holes 81 evenly distributed circumferentially around the axis of the cylinder block and a main shaft assembly hole 82 at the center for accommodating the main shaft 10. The cylinder block 80 has a plurality of plunger holes 81. Preferably, the number of the plunger holes is generally set to 7 or 9. The main shaft 10 passes through the main shaft assembly hole 82 of the cylinder block 80 and is connected to the cylinder block 80 by means of a connection key provided on the outer peripheral surface of its shaft body. The cylinder block 80 is supported on the main shaft 10 in a manner that moves synchronously with the main shaft 10.

[0090] Wherein, the other end face of the cylinder block 80 abuts against the distribution plate 90 to form a distribution pair, and the two ends are supported in a hydrostatic manner, as Figure 12 and 13 As shown, on the end face of the cylinder block 80 opposite to the distribution plate 90, there is provided a hydrostatic support surface 83 of the cylinder block. The hydrostatic support surface 83 of the cylinder block is supported on the distribution plate 90 and always maintains a sliding fit with the distribution plate 90. On the hydrostatic support surface 83 of the cylinder block, there are provided a plurality of kidney-shaped holes 85 of the cylinder block. Preferably, the kidney-shaped holes 85 of the cylinder block are evenly distributed on the hydrostatic support surface 83 of the cylinder block with the axis of the cylinder block as the center. On the end of the cylinder block, there is provided an oil passage hole 84 communicating the plunger hole 81 and the kidney-shaped hole 85 of the cylinder block.

[0091] During operation, the hydraulic pressure acts on the end of the cylinder block and is further transmitted to the distribution plate 90. Generally, the axial force of the hydraulic pressure acting on the end of the cylinder block 80 is greater than the support force of the distribution plate 90 acting on the end of the cylinder block through the oil film. Therefore, the end of the cylinder block always abuts against the distribution plate 90 and slides through a layer of oil film.

[0092] Specifically, the plunger 70 includes a plunger ball head 71 supported at one end on the plunger ball socket 58 of the sliding plate 50 and fixed to the end face of the sliding plate 50 via a pressing plate 60, a plunger center hole 72 for communicating the plunger hole 81 and the plunger ball socket 58, a tapered rod portion 73 with a conical outer peripheral surface, and a plunger portion 74 that is in clearance fit with the wall of the plunger hole of the cylinder block and can reciprocate therein. The plunger ball head 71 is spherical and can slide freely on the plunger ball socket 58 of the sliding plate 50. The plunger center hole 72 is a through-hole structure with a large aperture and serves as an oil suction and / or discharge passage. At least one sealing ring is often provided on the plunger portion 74 for sealing the liquid. The tapered rod portion 73 is generally tapered gradually from the plunger ball end to the plunger portion 74. When the plunger 70 moves to a certain position, the tapered rod portion 74 contacts the inner circumferential surface of the plunger hole 81 to play a role in force transmission. It should be noted that the plunger 70 is not limited to the tapered plunger type and may also include a connecting rod-plunger with ball heads at both ends or a spherical plunger with a universal hinge.

[0093] During operation, the hydraulic pressure acts on the plunger 70 and is further transmitted to the swash plate 50. Generally, the axial force exerted by the plunger 70 on the swash plate 50 is greater than the sum of the supporting force exerted by the swash plate 40 on the swash plate 50 through the oil film and the return force of the plunger 70. Therefore, the swash plate 50 always slides while abutting against the swash plate 40 through an oil film.

[0094] Considering that an initial seal is still required between the swash plate and the inclined plate during startup to establish the oil pressure as soon as possible, an initial sealing device must be provided on one side of the flow distribution swash plate pair.

[0095] Preferably, one type of initial sealing device, such as Figure 20 shown, a spring preloading device is provided between the swash plate 50 and the cylinder block 80. The spring preloading device gives a certain initial contact force between the flow distribution swash plate pair and the flow distribution pair. The spring preloading device includes a central spring 100, a retaining ring 101, and a ball joint 102. One end of the preloading spring force of the central spring 100 acts on the pressure plate 60 through the ball joint 102 and is further transmitted to the swash plate 50, and the other end acts on the end of the cylinder block and the flow distribution plate 90 through the retaining ring 101 with the preloading force.

[0096] Preferably, another type of initial sealing device, such as Figure 3 and 4 shown, a restraining device can also be provided on the swash plate 50 and / or the cylinder block 80. The restraining device has the function of restricting the swash plate 50 of the flow distribution swash plate pair from moving away from the swash plate 40 and restricting the cylinder block 80 of the flow distribution pair from moving away from the flow distribution plate 90.

[0097] Furthermore, the restraining device includes a swash plate stop portion that protrudes outward on the side of the swash plate 50 close to the hydrostatic bearing surface 51 of the swash plate and an engaging device provided on the swash plate support stop portion 41a. The stop portion is used to restrict the movement of the third bearing 23. The engaging device includes an engaging circumferential groove provided on the swash plate support stop portion 41a adjacent to the third bearing 23 and a snap ring (not shown) provided on the engaging inner circumferential groove. The snap ring restricts the swash plate from moving away from the end face of the swash plate 40 in a way that restrains the outward movement of the third bearing 23.

[0098] Predictably, an elastic gasket (not shown) can be appropriately provided between the stop portion and the third bearing 23 or between the snap ring and the third bearing 23, so that in addition to restricting the sliding disk from moving away from the end face of the swash plate, the constraint assembly also has a certain initial pre-tightening force to maintain the pre-tightened state between the sliding disk and the swash plate. Similarly, the constraint manner of the engaging device can also be realized by the interference fit between the third bearing 23 and the swash plate support stop portion 41a. An engaging circumferential groove and a snap ring cooperating with the engaging circumferential groove are provided on the swash plate support stop portion 41a adjacent to the third bearing 23 to further play a role in constraint. On one side of the cylinder block, the constraint device further includes a snap ring 141, which is used to restrict the movement of the end of the cylinder block away from the thrust plate.

[0099] Embodiment 2:

[0100] As Figures 19 to 22 shown, the difference from Embodiment 1 is that this embodiment is a closed system. Therefore, its manifold block structure and oil inlet and outlet channels are also different, and other structures can refer to those described in Embodiment 1.

[0101] Specifically, a high-pressure oil groove 37 and a low-pressure oil groove 39 are provided on the manifold block 35. The high-pressure oil groove 37 of the manifold block is respectively communicated with the high-pressure port 126b of the distribution shaft and the high-pressure distribution port 93 on the distribution disk 90. The low-pressure oil groove 39 of the manifold block is respectively communicated with the low-pressure port 126a of the distribution shaft and the low-pressure distribution port 92 on the distribution disk 90. During operation, the high-pressure oil flowing out of the cylinder block plunger hole 81 of the hydraulic pump assembly enters the high-pressure port 126b of the distribution shaft through the high-pressure oil groove 37 of the manifold block, and the low-pressure oil after the action of the hydraulic motor assembly returns to the cylinder block plunger hole 81 of the hydraulic pump assembly through the low-pressure oil groove 39 of the manifold block. This closed circuit is beneficial to reducing the volume of the fuel tank and improving the operating efficiency of the system.

[0102] Embodiment 3:

[0103] As Figure 20 shown, the difference from Embodiment 2 is that a valve group 130 for pressure and flow regulation is provided on the rear end cover 33, and other structures can refer to those described in Embodiment 2.

[0104] Specifically, a low-pressure distribution window 43, a high-pressure distribution window 44, and a distribution oil groove 42 are provided on the swash plate 40. The low-pressure distribution window 43 is communicated with the oil inlet 33a provided on the rear end cover 33 through the distribution oil groove 42. Further, the support surface of the swash plate 40 opposite to the rear end cover 33 has a cylindrical sliding arc surface 45 formed in a cylindrical shape. On the cylindrical sliding arc surface 45 of the swash plate 40, there are a groove-shaped low-pressure port 46 and a groove-shaped high-pressure port 47 configured in a groove shape. The groove-shaped low-pressure port 46 is communicated with the oil inlet 33a, and the groove-shaped high-pressure port 47 is communicated with the high-pressure oil hole 131 provided on the rear end cover 33.

[0105] Further, a valve group 130 is connected to the rear end cover 33. The oil inlet of the valve group 130 is communicated with the high-pressure oil hole 131. The valve group 130 is used for controlling the pressure, flow rate, and direction of the hydraulic pump assembly, and the flow rate. The valve group 130 includes one or a combination of a pressure valve, a flow valve, and a direction valve.

[0106] Embodiment 4:

[0107] As Figure 20 、 23 shown in FIGS. 24 to 25, the difference from Embodiments 2 and 3 is that an accumulator is provided on the electro-hydraulic drive system 5, and the other structures can refer to those described in Embodiments 2 and 3.

[0108] Specifically, an accumulator is provided on the rear end cover 33. The accumulator includes a high-pressure accumulator 132 and / or a low-pressure accumulator 133. The high-pressure accumulator 132 is connected to the valve group 130. The high-pressure accumulator has functions such as assisting in starting, stabilizing pressure, supplementing leaked oil, and providing an auxiliary control oil source. It can be predicted that the energy storage assembly can also be not connected to the rear end cover but placed independently, and the energy storage assembly is connected to the valve group through a hydraulic oil pipe.

[0109] Embodiment 5:

[0110] As Figure 23 and 24 shown, the main difference from other embodiments is that this embodiment is a rotary drum supported electro-hydraulic drive system.

[0111] Specifically, the electro-hydraulic drive system 5 includes a fourth bearing 24 and a fifth bearing 25. The fourth bearing 24 and the fifth bearing 25 are respectively clamped between the rotary drum 11 and the housing assembly, as Figure 23 shown; particularly, another rotary drum support method, as Figure 24 shown, includes a fourth bearing 24, and the fourth bearing 24 is clamped between the rotary drum 11 and the flow distribution block 35. The rotor assembly 9 of the motor and the hydraulic pump assembly are supported on the fourth bearing 24 and / or the fifth bearing 25 through the rotary drum 11 and rotate synchronously. The plunger 70 reciprocates in the plunger cavity of the cylinder block 80 to achieve oil suction and discharge work.

[0112] Embodiment 6:

[0113] As Figure 25 shown, the difference from other embodiments is that the structure of the rotor assembly is different.

[0114] Specifically, the rotor assembly 9 of the motor includes a rotor core 9a connected to the outer peripheral surface of the rotating cylinder 11 and permanent magnets 9c nested within the rotor core 9a. End rings 9d are provided at both ends of the permanent magnets 9c to restrict the axial movement of the permanent magnets.

[0115] Embodiment 7:

[0116] As Figure 19 shown, the difference from other embodiments is that an auxiliary oil supply pump 160 is provided on the rear end cover 33.

[0117] Specifically, one end of the main shaft 10 is connected to an oil supply pump 160 through a connecting device. The oil supply pump 160 is used to supply oil to the hydraulic pump assembly or provide hydraulic control operating force. The oil supply pump 160 is bolted to the rear end cover 33, and the externally connected oil supply pump 160 can be a gear pump, a vane pump, or the like.

[0118] The above content is a further detailed description of the present invention in combination with specific preferred technical solutions. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can be made. All technical solutions and their improvements that do not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims

1. A low-speed and high-torque stepless variable speed electro-hydraulic drive system, characterized in that: It includes a hydraulic motor assembly, a motor housing assembly connected to the hydraulic motor assembly, and a rotor assembly (9), a stator assembly (8), a hydraulic pump assembly, a flow distribution block (35), and a rotating cylinder (11) accommodated in the motor housing assembly. The hydraulic pump assembly includes a flow distribution pair and a plunger pair. The flow distribution pair includes an end of a cylinder block (80) and a flow distribution disc (90). The rotating cylinder (11) is respectively connected to the rotor assembly (9) and the cylinder block (80). The rotor assembly (9) drives the rotating cylinder (11) and the cylinder block (80) of the hydraulic pump assembly to rotate under the action of electromagnetic force. The hydraulic pump assembly outputs high-pressure oil and enters the hydraulic motor assembly through the flow distribution block (35), driving the hydraulic motor assembly to work, realizing the conversion from electrical energy to hydraulic energy and then to mechanical energy; The hydraulic pump assembly further includes a flow distribution sliding disc pair, which includes an inclined disc (40) and a sliding disc (50) supported on the inclined disc (40). The inclined disc (40) is supported on the rear end cover (33) of the motor housing assembly. The flow distribution block (35) is arranged in the housing cavity (34) of the motor housing assembly. A flow distribution block oil inlet (36) opening to the housing cavity (34) is arranged on the flow distribution block (35). A low-pressure oil distribution window (43) is arranged on the inclined disc (40). The low-pressure oil distribution window (43) is communicated with an oil inlet (33a) arranged on the rear end cover (33). An oil passage leading to the low-pressure oil distribution window (43) of the inclined disc (40) and an oil passage leading to the inside of the housing cavity (34) through an oil inlet fork (33c) are arranged on the oil inlet (33a) of the rear end cover (33). During operation, low-pressure oil enters the plunger holes (81) of the cylinder block (80) from the flow distribution block oil inlet (36) and the low-pressure oil distribution window (43) of the inclined disc (40) in a dual path to realize oil suction. The low-pressure cold oil entering the housing cavity (34) through the oil inlet fork (33c) flows through the stator assembly (8), the rotor assembly (9) of the motor assembly, and the three major friction pairs of the hydraulic pump assembly; The outer peripheral surface of the rotating cylinder (11) is connected to the rotor assembly (9). An inwardly extending connecting portion (12) is arranged inside the rotating cylinder (11). A plurality of oil passing holes (13) are arranged circumferentially on the connecting portion (12). The oil passing holes (13) communicate the two side housing cavities (34) of the motor housing assembly, enabling the smooth passage of low-pressure oil. The connecting portion (12) of the rotating cylinder (11) is in mating connection with the cylinder block (80).

2. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 1, characterized in that: The sliding disc (50) is of an integral disc-shaped structure, and a static pressure oil film support is formed between the sliding disc (50) and the inclined disc (40).

3. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 2, characterized in that: The flow distribution pair of the hydraulic pump assembly is supported on one side end face of the flow distribution block (35). The hydraulic motor assembly includes a motor cylinder block (122) and a flow distribution shaft (126). The flow distribution shaft (126) abuts against the other side end face of the flow distribution block (35).

4. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 3, characterized in that: A low-pressure distribution port (92) is provided on the distribution disk (90). The distribution block inlet port (36) is communicated with the low-pressure distribution port (92). During operation, the low-pressure cold oil in the housing cavity (34) enters the plunger hole (81) of the cylinder block (80) from the distribution block inlet port (36), taking away the heat in the housing cavity (34) to achieve self-cooling.

5. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 4, characterized in that: A distribution block high-pressure oil groove (37) is provided on the distribution block (35). A distribution shaft high-pressure port (126b) is provided on the distribution shaft (126). The distribution block high-pressure oil groove (37) is communicated with the distribution shaft high-pressure port (126b) and the high-pressure distribution port (93) on the distribution disk (90) respectively. During operation, the high-pressure oil flowing out of the cylinder block plunger hole (81) of the hydraulic pump assembly enters the distribution shaft high-pressure port (126b) through the distribution block high-pressure oil groove (37), driving the hydraulic motor assembly to rotate and drive the load to work.

6. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 1, characterized in that: A distribution block oil outlet passage (38) is provided on the distribution block (35). The distribution block oil outlet passage (38) opens to the housing cavity (34) of the motor housing assembly, so that the low-pressure oil after the action of the hydraulic motor assembly is discharged into the housing cavity (34).

7. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 5, characterized in that: During operation, the low-pressure oil enters the plunger hole (81) of the cylinder block (80) through the low-pressure distribution port (92) of the distribution disk (90) and the low-pressure oil distribution window (43) of the swash plate (40) from the distribution block inlet port (36) to achieve oil suction.

8. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 7, wherein: A check valve (150) is provided on the distribution block (35). The check valve (150) is communicated with the distribution block high-pressure oil groove (37). The check valve (150) only allows oil to enter unidirectionally from the housing cavity (34) to the distribution block high-pressure oil groove (37). When the hydraulic motor assembly changes to the pump working condition, the check valve (150) plays a role in supplementary oil supply.

9. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 3, wherein: A distribution block high-pressure oil groove (37) and a distribution block low-pressure oil groove (39) are provided on the distribution block (35). A distribution shaft high-pressure port (126b) and a distribution shaft low-pressure port (126a) are provided on the distribution shaft (126). The distribution block high-pressure oil groove (37) is communicated with the distribution shaft high-pressure port (126b) and the high-pressure distribution port (93) on the distribution disk (90) respectively. The distribution block low-pressure oil groove (39) is communicated with the distribution shaft low-pressure port (126a) and the low-pressure distribution port (92) on the distribution disk (90) respectively. During operation, the high-pressure oil flowing out of the cylinder block plunger hole (81) of the hydraulic pump assembly enters the distribution shaft high-pressure port (126b) through the distribution block high-pressure oil groove (37), and the low-pressure oil after the action of the hydraulic motor assembly returns to the cylinder block plunger hole (81) of the hydraulic pump assembly through the distribution block low-pressure oil groove (39).

10. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 9, wherein: The bearing surface of the swash plate (40) facing the rear end cover (33) has a cylindrical sliding arc surface (45) formed in a cylindrical shape. On the cylindrical sliding arc surface (45) of the swash plate (40), there are a grooved low-pressure port (46) and a grooved high-pressure port (47) configured in a groove shape. The grooved low-pressure port (46) communicates with the oil inlet (33a), and the grooved high-pressure port (47) communicates with a high-pressure oil hole (131) provided on the rear end cover (33).

11. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 10, wherein: A valve group (130) is connected to the rear end cover (33). The oil inlet of the valve group (130) communicates with the high-pressure oil hole (131). The valve group (130) is used for controlling the pressure, flow rate, and direction of the hydraulic pump assembly. The valve group (130) includes one or a combination of a pressure valve, a flow valve, and a direction valve.

12. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 11, characterized in that: An accumulator is provided on the electro-hydraulic drive system (5). The accumulator includes a high-pressure accumulator (132) and / or a low-pressure accumulator (133). The accumulator is connected to the valve group (130). The accumulator includes one or more functions such as assisting in starting, stabilizing pressure, supplementing leaked oil, and providing an auxiliary control oil source.

13. The low-speed high-torque continuously variable electro-hydraulic drive system according to claim 1, wherein: A variable mechanism (110) for controlling the displacement of the hydraulic pump assembly is provided on the motor housing assembly. The variable mechanism (110) is set as a swash plate angle control type variable structure. The variable mechanism (110) includes a variable piston (111), a control valve (112), and a variable spring (113). The variable piston (111) drives the swash plate (40) to rotate.

14. The low-speed high-torque continuously variable electro-hydraulic drive system according to any one of claims 1 to 13, characterized in that: The hydraulic pump assembly is of a shaft-supported structure, and it further includes a main shaft (10), a first bearing (21), and a second bearing (22). The axis of the main shaft of the main shaft (10) coincides with the axis of the cylinder block of the cylinder block (80). One end of the main shaft (10) penetrates through the distribution pair to the distribution block (35) and is supported on the first bearing (21), and the other end penetrates through the distribution sliding disk pair to the rear end cover (33) of the motor housing assembly and is supported on the second bearing (22). The cylinder block (80) is supported on the main shaft (10) and is connected to the main shaft (10) through a key connection to achieve synchronous rotation. The plunger pair includes the plunger hole wall of the cylinder block (80) and the plunger (70). The plunger (70) reciprocates in the plunger cavity of the cylinder block (80) to achieve oil suction and discharge work.

15. The low-speed high-torque continuously variable electro-hydraulic drive system according to any one of claims 1 to 13, characterized in that: The hydraulic pump assembly is of a rotating cylinder-supported structure, and it further includes a fourth bearing (24) and / or a fifth bearing (25). The fourth bearing (24) and the fifth bearing (25) are respectively clamped between the rotating cylinder (11) and the motor housing assembly, or the fourth bearing (24) is supported between the rotating cylinder (11) and the distribution block (35). The rotor assembly (9) and the hydraulic pump assembly are supported on the fourth bearing (24) and / or the fifth bearing (25) through the rotating cylinder (11) and achieve synchronous rotation. The plunger pair includes the plunger hole wall of the cylinder block (80) and the plunger (70). The plunger (70) reciprocates in the plunger cavity of the cylinder block (80) to achieve oil suction and discharge work.

Images