Hydraulic drive axle without oil distributor

Abstract

The utility model discloses a hydraulic drive axle without an oil distributor, which comprises a drive axle shaft, motors and tires, each end of the drive axle shaft is connected with one motor and at least one tire, a stator is fixedly sleeved outside a main shaft, a main body part of the stator is provided with a plurality of plunger grooves, a plunger is movably arranged in each plunger groove, and the main shaft is provided with a piston. Plungers are pushed by hydraulic oil in plunger grooves to make contact with the wavy inner surface of the middle rotor and push the middle rotor to rotate, each plunger groove is provided with a first plunger groove oil channel, a control valve penetrates through the first plunger groove oil channels, and guide rails on the two end cover rotors push the control valve to move in a reciprocating mode so that the control valve can alternately close the two ends of the first plunger groove oil channels. The free moving assembly prevents the plunger from driving the inner surface of the middle rotor when the plunger is not subjected to the pressure of the hydraulic oil by applying elastic force to the plunger. According to the utility model, the motor shell can be driven forwards and backwards, the torque is large, the oil way sealing performance is good, the axial size and volume of the motor are small, the service life is long, and a vehicle is not subjected to plunger resistance when moving freely.

Description

Technical Field

[0001] The utility model belongs to the technical field of engineering vehicle drive axles, and particularly relates to a hydraulic drive axle without an oil distributor. Background Art

[0002] In engineering and technical fields such as wind power installation, mines, factory areas, port terminals, and special environment work areas, the construction sites are generally located in mountainous areas and other places with extremely poor road traffic conditions. The equipment required at the construction sites is often relatively large, such as wind turbine blades. This poses higher requirements for transportation engineering vehicles, demanding that the engineering vehicles have strong climbing ability, cross-country ability, and a safer downhill ability. In the prior art, there are still many defects in the above-mentioned engineering transport vehicles. For example, the driving motor and the drive axle shaft jointly bear the weight, resulting in problems such as short service life and easy damage of the driving motor. Due to the rugged mountain roads and the rotation of the drive axle shaft, the driving motor cannot be stably supported, affecting its safety. Again, there are many steep slopes on mountain roads. When the vehicle goes downhill, it often needs to continuously brake to make the vehicle go downhill safely. However, due to the large tonnage of the engineering vehicle, continuous braking will seriously affect the brake life. Currently, fire accidents and major accidents caused by friction heat generation due to the current braking mode occur frequently. In addition, many existing hydraulic drive motors require special and complex oil distributors to distribute hydraulic oil for the motor to achieve the periodic operation of the motor. This often results in a large axial dimension and volume of the motor, and the oil distributor itself operates or needs to cooperate with other operating components to achieve the periodic connection of the oil circuit, that is, the oil circuit is distributed on two components that move relative to each other, resulting in a complex oil circuit and poor sealing performance. Content of the Utility Model

[0003] Aiming at the above problems existing in the prior art, the purpose of the utility model is to provide a hydraulic drive axle without an oil distributor, which realizes the forward and reverse driving of the motor housing by changing the flow direction of the hydraulic oil, thereby realizing the forward and backward driving of the wheels. It can achieve a large driving torque, has a large load capacity, is flexible in operation, has good oil circuit sealing performance, does not require a complex oil distributor, greatly reduces the axial dimension and volume of the motor, has a higher service life and power of the motor, the vehicle will not be affected by the resistance of the plunger during free travel, is driven by hydraulic oil, is convenient for automatic and intelligent setting with other controls of the vehicle body, and is conducive to energy conservation and emission reduction.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A hydraulic drive axle without an oil distributor includes a drive axle shaft, a motor, and a tire. The drive axle shaft is a long rod-shaped structure with a hollow interior or a through hole. Each end of the drive axle shaft is connected to a motor and at least one tire. The motor includes a main shaft, a rotor, a stator, a free travel component, a plunger, and a control valve. The main shaft is coaxially connected to the drive axle shaft, and the stator is fixedly sleeved outside the main shaft;

[0006] The stator includes a stator main body part integrally connected and two stator connection parts respectively located on both sides of the stator main body part. A plurality of plunger grooves are provided on the stator main body part. The plunger grooves are grooves provided on the circumferential outer surface of the stator main body part. The plurality of plunger grooves are evenly arranged at intervals along the circumferential direction of the stator. A plunger is movably arranged in each plunger groove. Each plunger groove is equipped with a first oil passage of the plunger groove. The two ends of the first oil passage of the plunger groove are respectively the inlet and outlet of hydraulic oil, and the middle part is communicated with the plunger groove.

[0007] The tire is rotatably sleeved outside the rotor. The rotor includes a middle rotor and two end-cover rotors. The two end-cover rotors are respectively fixedly connected to the two end faces of the middle rotor. The two end-cover rotors are respectively sleeved outside the two stator connection parts through bearings. The inner surface of the middle rotor is wavy along the circumferential direction. The plunger contacts the inner surface of the middle rotor under the push of the hydraulic oil in the plunger groove and drives the middle rotor to rotate. A plurality of wavy guide rails located in the same ring are provided on the end face of each end-cover rotor facing the other end-cover rotor. The concave and convex trends of the guide rails on the two end-cover rotors are arranged staggeredly.

[0008] The control valve includes a connecting rod part and two large head parts thicker than the connecting rod part connected to both ends of the connecting rod part. The control valve passes through the first oil passage of the plunger groove. The outer diameter of the connecting rod part is smaller than the aperture of the first oil passage of the plunger groove. The two large head parts can be respectively inserted into and close the two ends of the first oil passage of the plunger groove. The two end parts of the control valve respectively contact the guide rails on the two end-cover rotors. As the rotor rotates, the guide rails on the two end-cover rotors push the control valve to reciprocate, so that the control valve alternately closes the two ends of the first oil passage of the plunger groove.

[0009] The free-travel component prevents the plunger from contacting and driving the inner surface of the middle rotor when the plunger is not under the pressure of hydraulic oil by applying a pulling force to the plunger.

[0010] As a further improvement of the above technical solution:

[0011] Each plunger groove is further equipped with a first stator oil passage, a second stator oil passage, and a second oil passage of the plunger groove. One inlet and outlet of the first stator oil passage are provided on the inner surface of the stator main body part, and the other inlet and outlet are communicated with one end of the first oil passage of the plunger groove. The other end of the first oil passage of the plunger groove is communicated with one end of the second stator oil passage. The inlet and outlet of the other end of the second stator oil passage are provided on the inner surface of the stator main body part. One end of the second oil passage of the plunger groove is communicated with the middle part of the first oil passage of the plunger groove, and the other end is communicated with the plunger groove.

[0012] One of the first stator oil passage and the second stator oil passage is an oil inlet passage, and the other is an oil outlet passage. The first stator oil passage and the second stator oil passage are both passages provided in the radial direction of the stator main body part. The length direction of the first oil passage of the plunger groove is parallel to the axial direction of the stator.

[0013] The free travel component includes a plunger top roller and two springs. The plunger top roller passes through one end of the plunger that extends beyond the plunger groove. The two springs are respectively connected to both ends of the plunger top roller. One end of each spring is fixed on the stator, and the other end is connected to one end of the plunger top roller.

[0014] The two springs are respectively located in two auxiliary holes on both sides of the corresponding plunger groove.

[0015] The stator main body is also provided with a stator oil drain passage for guiding and discharging the leaked hydraulic oil in the motor. The stator oil drain passage includes a first stator oil drain passage and a second stator oil drain passage. The first stator oil drain passage is a groove provided on the inner surface of the stator and is arranged in a circle along the circumferential direction of the inner surface of the stator. One end of the second stator oil drain passage communicates with the first stator oil drain passage, and the port of the other end is arranged on the circumferential outer surface of the stator main body.

[0016] The inner surface of the stator is also provided with a first groove and a second groove. Both the first groove and the second groove are grooves provided on the inner surface of the stator and are both grooves arranged in a circle along the circumferential direction of the inner surface of the stator. Each stator first oil passage communicates with the first groove, and each stator second oil passage communicates with the second groove. The main shaft is provided with radial first holes, second holes and an oil drain hole. When the stator is sleeved on the main shaft, the first hole communicates with the first groove, the second hole communicates with the second groove, and the oil drain hole communicates with the first stator oil drain passage. The first hole, the second hole and the oil drain hole on the main shaft all communicate with the axial through hole of the main shaft.

[0017] An oil inlet pipe, an oil return pipe and an oil drain pipe are inserted into the drive axle shaft from the middle of the drive axle shaft towards each end of the drive axle shaft. The oil inlet pipe, the oil return pipe and the oil drain pipe pass through the drive axle shaft and then are inserted into the main shaft. The oil drain pipe passes through the axial through hole of the main shaft and is inserted into the oil drain hole. The oil inlet pipe passes through the axial through hole of the main shaft and is inserted into the first hole or the second hole. The oil return pipe passes through the axial through hole of the main shaft and is inserted into the second hole or the first hole.

[0018] The tire is sleeved outside the steel rim. The steel rim is installed on the hub. The hub is installed on the drive axle shaft through bearings. The rotor of the motor is installed on the steel rim.

[0019] The beneficial effects of the present utility model are:

[0020] (1) By changing the flow direction of the hydraulic oil, the motor housing is driven forward and backward, thereby realizing the forward and backward driving of the wheel.

[0021] (2) The adjustment of the vehicle body's dynamic torque is achieved by adjusting the pressure of the hydraulic oil. The vehicle speed can be adjusted flexibly, enabling a relatively large driving torque. It has a large load capacity and is flexible in operation. It overcomes the drawback of existing vehicles that can only reduce speed by stepping on the brake. It can achieve a slow-speed drive by reducing the pressure of the hydraulic oil, thereby reducing speed. It can be used as an additional brake for heavy vehicles, increasing the braking efficiency, improving the safety factor of the vehicle and the service life of the brakes. It is applicable to the transportation of medium and large-sized equipment in areas with harsh road conditions such as factories, mines, port terminals, mountainous areas, and the military.

[0022] (3) The weight of the motor is borne by the steel ring instead of the combined bridge bearing, making the motor support and operation smoother, enabling a more stable drive, overcoming the contradiction that the drive and load cannot be separated, thus ensuring the reliability of operation and the convenience of maintenance, and effectively improving the service life of the hydraulic motor.

[0023] (4) The oil inlet and outlet of each plunger groove are controlled by the reciprocating movement of the control valve. The reciprocating movement of the control valve is pushed by the guide rails on the two rotating rotor end covers. It is a pure mechanical structure with precise control. The control valve passes through the stator, without the need to separately occupy a large axial space. The hydraulic oil channels on the motor are all on the stator and are not distributed on the two moving parts. The oil circuit has good sealing performance, without the need to set up a complex oil distributor, greatly reducing the axial size and volume of the motor, and increasing the service life and power of the motor.

[0024] (5) The free movement component prevents the plunger from contacting the inner surface of the middle rotor when not under the pressure of the hydraulic oil, thereby preventing the plunger from generating frictional resistance to the rotor when the vehicle equipped with the drive axle is in free movement. Free movement means the operation of the vehicle when it is being towed and not driven by the motor.

[0025] (6) The hollow design inside the hollow shaft or the drilled hole in the shaft facilitates the layout of the oil passage, making the overall structure more compact. The non-exposed oil pipes are more conducive to safe driving.

[0026] (7) Driven by hydraulic oil, it is convenient for automatic and intelligent settings with other controls of the vehicle body and is conducive to energy conservation and emission reduction. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of an embodiment of the present utility model.

[0028] Figure 2 is a schematic structural diagram of the motor of an embodiment of the present utility model.

[0029] Figure 3 is Figure 2 an enlarged schematic diagram of part A of

[0030] Figure 4Schematic diagram of the matching structure between the middle rotor and the plunger of a motor according to an embodiment of the present invention.

[0031] Figure 5 Schematic diagram of the end - cover rotor structure according to an embodiment of the present invention.

[0032] Figure 6 Schematic diagram of the stator structure of a motor according to an embodiment of the present invention.

[0033] Figure 7 Schematic diagram of the operation of the control valve after the circumferential expansion of the end - cover rotor of a motor according to an embodiment of the present invention. Detailed implementation manners

[0034] The following will describe the detailed implementation manners of the present invention in conjunction with the accompanying drawings. It should be understood that the detailed implementation manners described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0035] For the sake of convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations are made for the spatial relative descriptions used here.

[0036] A hydraulic drive axle without an oil distributor, as Figures 1 to 7 shown, includes a drive axle shaft 1, a motor 2, a wheel hub 3, a steel rim 4, a tire 5, a connecting flange 6, a wheel hub bearing 7, a brake drum 8, and a brake shoe bracket 9.

[0037] As Figure 1 shown, the drive axle shaft 1 is a long rod - shaped structure with a hollow interior or a through - hole. Each end of the drive axle shaft 1 is connected to a motor 2 and at least one tire 5. In this embodiment, each end of the drive axle shaft 1 is connected to a motor 2 and two tires 5.

[0038] In this embodiment, there are two steel rings 4 at each end of the drive axle shaft 1, and a tire 5 is sleeved outside each steel ring 4. The two steel rings 4 at each end of the drive axle shaft 1 are coaxially connected to the wheel hub 3, and the two steel rings 4 are arranged axially along the drive axle shaft 1. The wheel hub 3 is installed on the drive axle shaft 1 through wheel hub bearings 7, that is, the wheel hub 3 is rotatable relative to the drive axle shaft 1. The connecting flange 6 and the motor 2 are located in the inner ring of one steel ring 4, and the wheel hub 3 is located in the inner ring of the other steel ring 4. In this way, the axial space of the drive axle is fully utilized, making the overall structure more compact. Specifically as follows:

[0039] Each end of the drive axle shaft 1 is connected to the motor 2 and the tire 5 through the wheel hub 3. Each wheel hub 3 is sleeved outside the drive axle shaft 1 through two wheel hub bearings 7. The two wheel hub bearings 7 are arranged in parallel at intervals on the drive axle shaft 1, and both ends of the wheel hub 3 are sleeved on the outer rings of the two wheel hub bearings 7. In this way, the wheel hub 3 is rotatably installed on the drive axle shaft 1. Preferably, there is a shaft shoulder on the drive axle shaft 1 for limiting the wheel hub bearing 7. One end face of a wheel hub bearing 7 contacts the shaft shoulder position, and the other end face contacts the limiting protrusion of the wheel hub 3; one end face of the other wheel hub bearing 7 contacts another limiting protrusion of the wheel hub 3, and the other end face contacts the motor 2, so as to realize the axial limitation of the two wheel hub bearings 7 and the wheel hub 3 on the drive axle shaft 1. Obviously, there are two wheel hubs 3, and one wheel hub 3 is provided at each end of the drive axle shaft 1.

[0040] The steel ring 4 is annular, the steel ring 4 and the drive axle shaft 1 are arranged with a common central axis, the steel ring 4 is fixedly connected to the wheel hub 3. Preferably, the inner diameter of the steel ring 4 is greater than the outer diameter of the connecting flange 6. The tire 5 is sleeved outside the steel ring 4.

[0041] The connecting flange 6 is annular, the connecting flange 6 and the drive axle shaft 1 are arranged with a common central axis, the connecting flange 6 is fixedly connected to the steel ring 4. Preferably, the connecting flange 6 is located on one side of a wheel hub 3 away from the other wheel hub 3. The motor 2 and the drive axle shaft 1 have a common central axis, and the motor 2 is fixedly connected to the connecting flange 6 while connecting one end of the drive axle shaft 1. Preferably, the diameter of the connecting flange 6 is greater than the outer diameter of the drive axle shaft 1 and the outer diameter of the wheel hub 3, and the motor 2 is located in the inner ring of the connecting flange 6.

[0042] Based on the above structure, both the connecting flange 6 and the wheel hub 3 are fixedly connected to the steel ring 4, and the motor 2 is connected through the connecting flange 6 and the steel ring 4, that is, the motor 2 is supported by the steel ring 4.

[0043] The brake drum 8 and the brake shoe support 9 are both fixedly connected to the steel ring 4. Preferably, both the brake drum 8 and the brake shoe support 9 are connected to the wheel hub 3 and are located in the inner ring of the steel ring 4 where the wheel hub 3 is located.

[0044] The motor 2 is a hydraulic motor. As Figure 2As shown, the motor 2 includes a main shaft 29, a rotor, a stator 24, a free travel assembly 26, a plunger 27, and a control valve 25. The stator 24 is fixedly connected to the main shaft 29, and the rotor can rotate relative to the stator 24 with the main shaft 29 as the central axis. The main shaft 29 and the drive axle shaft 1 are coaxially and fixedly connected. It is also possible to use one end of the drive axle shaft 1 as the main shaft 29, that is, the rotor and the stator 24 are directly installed at one end of the drive axle shaft 1.

[0045] The main shaft 29 is provided with an axial hole communicating with the through hole on the drive axle shaft 1 and a through hole communicating with the oil passage on the stator 24.

[0046] The rotor includes a middle rotor 21 and end cover rotors. There are two end cover rotors, namely a front end cover rotor 22 and a rear end cover rotor 23. The front end cover rotor 22 and the rear end cover rotor 23 are respectively fixedly connected to the two end faces of the middle rotor 21. The front end cover rotor 22 and the rear end cover rotor 23 are fixedly connected to the middle rotor 21 by bolts. The middle rotor 21 is as Figures 2 to 4 As shown, the middle rotor 21 is of a cylindrical structure, that is, the middle rotor 21 is hollow. The middle rotor 21 has an outer surface 211, an inner surface 212, and two end faces, as Figure 4 shown. The outer surface 211 of the middle rotor 21 is a cylindrical outer surface. The inner surface 212 of the middle rotor 21 is a curved surface. Specifically, in a plane perpendicular to the axial direction of the middle rotor 21, the inner surface 212 of the middle rotor 21 is wavy, and the wavy shape is formed by sequentially connecting a plurality of wave units end to end. An object fits along the inner surface 212 of the middle rotor 21 and moves clockwise along the circumferential direction of the middle rotor 21 as Figure 4 shown. When passing through one of the wave units, the object will first gradually approach the central axis of the middle rotor 21. Let this section of the path of the wave unit be the descending section 2121; the object will then gradually move away from the central axis of the middle rotor 21. Let this section of the path of the wave unit be the ascending section 2122.

[0047] The front end cover rotor 22, the rear end cover rotor 23, and the middle rotor 21 are connected to form the outer shell or housing of the motor 2. The housing has an internal cavity, that is, the front end cover rotor 22, the rear end cover rotor 23, and the middle rotor 21 have an enclosed space. The housing of the motor 2 is fixedly connected to the connecting flange 6.

[0048] The end cover rotor is as Figure 5As shown, it is a thin-walled cylindrical structure, or an annular plate-like structure. On one end face of the end cover rotor, there are a plurality of guide rails 20. The guide rails 20 protrude from the end face of the end cover rotor. The guide rails 20 are in an arch shape or a wave shape, that is, along the length direction of the guide rails 20, the height of the guide rails 20 first gradually increases and then gradually decreases. In other words, when an object moves along the upper surface B of the guide rails 20, the distance between the object and the end face C of the end cover rotor first increases and then decreases, changing periodically in this way. The plurality of guide rails 20 are evenly arranged on the same ring, and this ring and the end cover rotor share the same central axis. During installation, the side of the front end cover rotor 22 with the guide rails 20 faces the side of the rear end cover rotor 23 with the guide rails 20, and the guide rails 20 on the front end cover rotor 22 and the guide rails 20 on the rear end cover rotor 23 are staggered, that is, the top of the guide rails 20 on the front end cover rotor 22 faces the connection point between two adjacent guide rails 20 on the rear end cover rotor 23. The connection point between two adjacent guide rails 20 is the bottom or the lowest point of the guide rails 20. In this way, axially, the distance from any point on the upper surface B of the guide rails 20 of the front end cover rotor 22 to the guide rails 20 on the rear end cover rotor 23 is equal everywhere.

[0049] The stator 24 is as Figure 6 shown. The stator 24 has a central through hole. The shape of the through hole is cylindrical, and this through hole is for the main shaft 29 to pass through. The stator 24 is fixedly sleeved on one end of the main shaft 29. Preferably, there is a circle of teeth on the inner wall of the through hole of the stator 24, and there is a circle of teeth on the outer surface of one end of the main shaft 29. The teeth on the stator 24 and the teeth on the main shaft 29 are engaged with each other, so that the stator 24 and the main shaft 29 are relatively fixedly connected together.

[0050] The stator 24 includes a stator main body part 201 integrally connected and two stator connection parts 202. The two stator connection parts 202 are respectively located on both sides of the main body part 201. The stator main body part 201 and the stator connection parts 202 are both cylindrical. The outer diameter of the stator main body part 201 is larger than the outer diameter of the stator connection parts 202. The front end cover rotor 22 is sleeved outside one stator connection part 202 through a bearing 28, and the rear end cover rotor 23 is sleeved outside the other stator connection part 202 through another bearing 28. The main body part 201 is located in the space enclosed by the front end cover rotor 22, the rear end cover rotor 23 and the middle rotor 21, and the stator main body part 201 does not contact the middle rotor 21, the front end cover rotor 22 and the rear end cover rotor 23. The stator 24, the middle rotor 21, the front end cover rotor 22 and the rear end cover rotor 23 share the same central axis.

[0051] On the stator main body part 201, there are a stator first oil passage 241, a stator second oil passage 242, a stator oil drain passage, a plunger groove first oil passage 245, a plunger groove second oil passage 246 and a plunger groove 244, as Figure 2 、 3As shown in FIGS. 5 and 6. The plunger groove 244 is a groove provided on the circumferential outer surface of the stator main body 201. There are a plurality of plunger grooves 244, and the plurality of plunger grooves 244 are evenly spaced along the circumferential direction of the stator 24.

[0052] There are a plurality of plungers 27, and the plurality of plungers 27 can be respectively inserted into the plurality of plunger grooves 244. The plunger 27 is equivalent to a piston, placed in the plunger groove 244 without being fixedly connected. The plunger 27 fits against the circumferential wall surface of the plunger groove 244, so that a volume space is formed between the plunger 27 and the bottom surface of the plunger groove 244. When the plunger 27 reciprocates in the plunger groove 244 in a piston-like manner, the volume of the volume space changes. In this embodiment, one end of the plunger 27 close to the bottom surface of the plunger groove 244 is cylindrical, and the other end away from the bottom surface of the plunger groove 244 is conical-like. One end of the plunger 27 is located inside the plunger groove 244, and the other end is located outside the plunger groove 244, that is, the plunger 27 extends beyond the plunger groove 244.

[0053] The stator first oil passage 241, the stator second oil passage 242, the stator oil drain passage, the plunger groove first oil passage 245, and the plunger groove second oil passage 246 are all passages provided on the stator main body 201. Each plunger groove 244 is equipped with a stator first oil passage 241, a stator second oil passage 242, a plunger groove first oil passage 245, and a plunger groove second oil passage 246. One of the stator first oil passage 241 and the stator second oil passage 242 is an oil inlet passage, and the other is an oil outlet passage. The hydraulic oil sequentially passes through the plunger groove first oil passage 245, the plunger groove second oil passage 246 into the plunger groove 244 from the oil inlet passage to push the plunger 27 to move. The hydraulic oil in the plunger groove 244 sequentially flows to the oil outlet passage through the plunger groove second oil passage 246 and the plunger groove first oil passage 245, as Figure 2 and 3 shown, one inlet and outlet of the stator first oil passage 241 is provided on the inner surface of the stator main body 201, and the other inlet and outlet communicates with one end of the plunger groove first oil passage 245. The other end of the plunger groove first oil passage 245 communicates with one end of the stator second oil passage 242. The inlet and outlet of the other end of the stator second oil passage 242 is provided on the inner surface of the stator main body 201. One end of the plunger groove second oil passage 246 communicates with the middle part of the plunger groove first oil passage 245, and the other end communicates with the plunger groove 244. The connection part between the plunger groove 244 and the plunger groove second oil passage 246 is located on the bottom surface of the plunger groove 244. Specifically, viewed from the axial direction of the stator 24, the stator first oil passage 241 and the stator second oil passage 242 are respectively located on both sides of the plunger groove 244. The stator first oil passage 241 and the stator second oil passage 242 are both passages provided in the radial direction of the stator main body 201. The length direction of the plunger groove first oil passage 245 is parallel to the axial direction of the stator 24, and the plunger groove first oil passage 245 is located between the plunger groove 244 and the middle through hole of the stator 24.

[0054] The stator oil drain passage is used to guide and discharge the leaked hydraulic oil in the motor 2. The stator oil drain passage includes a first stator oil drain passage 243 and a second stator oil drain passage (not shown in the figure). The first stator oil drain passage 243 is a groove provided on the inner surface of the stator 24. The first stator oil drain passage 243 is arranged in a circle along the circumferential direction of the inner surface of the stator 24. When the main shaft 29 is connected to the stator 24, the outer surface of the main shaft 29 fits the inner surface of the stator 24, and a channel for accommodating hydraulic oil is formed between the outer surface of the main shaft 29 and the first stator oil drain passage 243. The second stator oil drain passage is a radial through hole on the stator main body 201. One end of the second stator oil drain passage communicates with the first stator oil drain passage 243, and the port of the other end is arranged on the circumferential outer surface of the stator main body 201. There are multiple second stator oil drain passages, and one second stator oil drain passage is provided between two adjacent plunger grooves 244.

[0055] There are multiple control valves 25, and each plunger groove 244 is equipped with a control valve 25. The control valve 25 includes a connecting rod portion 252 and two large head portions 251. The two large head portions 251 are respectively connected to both ends of the connecting rod portion 252. The large head portion 251 and the connecting rod portion 252 are both rod-shaped structures, and the length directions of the large head portion 251 and the connecting rod portion 252 are the same. The diameter of the large head portion 251 is larger than the diameter of the connecting rod portion 252. The diameter of the connecting rod portion 252 is smaller than the aperture of the first oil passage 245 of the plunger groove, and the diameter of the large head portion 251 is not less than the aperture of the first oil passage 245 of the plunger groove. The length direction of the control valve 25 is parallel to the axial direction of the stator 24. The control valve 25 passes through the stator main body 201. Specifically, the control valve 25 passes through the first oil passage 245 of the plunger groove. The two end portions in the length direction of the control valve 25 respectively contact the upper surface B of the guide rail 20 on the front end cover rotor 22 and the upper surface B of the guide rail 20 on the rear end cover rotor 23. In other words, one large head portion 251 contacts the upper surface B of the guide rail 20 on the front end cover rotor 22, and the other large head portion 251 contacts the upper surface B of a guide rail 20 on the rear end cover rotor 23.

[0056] Based on the above structure, when the rotor rotates relative to the stator 24, the control valve 25 can move along the length direction of the first oil passage 245 of the plunger groove under the action of the guide rail 20 on the front end cover rotor 22 and the guide rail 20 on the rear end cover rotor 23. Specifically, as Figure 7 shown in the schematic diagram after unfolding the front end cover rotor 22 and the rear end cover rotor 23 along their respective circumferences, the synchronous rotation of the front end cover rotor 22 and the rear end cover rotor 23 is equivalent to the synchronous up and down movement of the unfolded front end cover rotor 22 and the rear end cover rotor 23 in Figure 7 . When one large head portion 251 of the control valve 25 contacts the connection point between two adjacent guide rails 20 of the front end cover rotor 22 and the other large head portion 251 contacts the top of the upper surface B of a guide rail 20 of the rear end cover rotor 23, as Figure 7The control valve 25 shown by the solid line. As the front end cover rotor 22 and the rear end cover rotor 23 rotate, the front end cover rotor 22 will push the control valve 25 towards the Figure 7 right side shown, until a large head 251 of the control valve 25 contacts the top of the upper surface B of a guide rail 20 of the front end cover rotor 22, and another large head 251 contacts the junction between two adjacent guide rails 20 of the rear end cover rotor 23, as shown by the Figure 7 dashed line in. As the front end cover rotor 22 and the rear end cover rotor 23 continue to rotate, the rear end cover rotor 23 will push the control valve 25 towards the Figure 7 left side in, until the control valve 25 reaches the Figure 7 state shown by the solid line in. Obviously, the left and right movement of the control valve 25 is the reciprocating movement of the control valve 25 in the stator 24 or the axial direction of the rotor. It should be noted that in Figure 7 , the front end cover rotor 22 and the rear end cover rotor 23 move up or down relative to the control valve 25. In order to clarify the changes of the control valve 25, in Figure 7 , the solid line and the dashed line are used to represent two states of the control valve 25.

[0057] The above-mentioned reciprocating movement of the control valve 25 is to control that only one of the oil inlet passage and the oil outlet passage of the plunger groove 244 is in the open state at the same time. In other words, the control valve 25 can control the connection and disconnection of the passage between the first oil passage 241 of the stator and the first oil passage 245 of the plunger groove, and the passage between the second oil passage 242 of the stator and the first oil passage 245 of the plunger groove. Specifically, the control valve 25 can move to a large head 251 to block and cut off the passage between the first oil passage 241 of the stator and the first oil passage 245 of the plunger groove while the other large head 251 does not block the passage between the second oil passage 242 of the stator and the first oil passage 245 of the plunger groove. In other words, under the action of the control valve 25, when one of the passage between the first oil passage 241 of the stator and the first oil passage 245 of the plunger groove and the passage between the second oil passage 242 of the stator and the first oil passage 245 of the plunger groove is connected, the other is disconnected, that is, the two must be one disconnected and the other connected at the same time, and cannot be connected at the same time or disconnected at the same time.

[0058] In order to ensure that the above two passages are one disconnected and the other connected at the same time, the length of the connecting rod portion 252 is equal to the length of the first oil passage 245 of the plunger groove. The length of the first oil passage 245 of the plunger groove is its axial dimension, and the outer diameter of the large head 251 is equal to the aperture of the first oil passage 245 of the plunger groove, that is, the large head 251 can be inserted into the first oil passage 245 of the plunger groove. When the control valve 25 is in Figure 7When in the position and state shown by the solid line, the large head 251 in the first stator oil passage 241 does not insert into the first oil passage 245 of the plunger groove. There is a space between the first oil passage 245 of the plunger groove and the connecting rod portion 252, and this space communicates with the first stator oil passage 241, that is, the passage between the first stator oil passage 241 and the first oil passage 245 of the plunger groove is connected; the large head 251 in the second stator oil passage 242 partially inserts into the first oil passage 245 of the plunger groove and blocks one end of the first oil passage 245 of the plunger groove, that is, the passage between the second stator oil passage 242 and the first oil passage 245 of the plunger groove is cut off. When the control valve 25 moves to the right, the large head 251 in the first stator oil passage 241 gradually approaches the first oil passage 245 of the plunger groove, and the large head 251 in the second stator oil passage 242 gradually withdraws from the first oil passage 245 of the plunger groove. When the large head 251 of the first stator oil passage 241 just enters the first oil passage 245 of the plunger groove, the large head 251 in the second stator oil passage 242 completely withdraws from the first oil passage 245 of the plunger groove. At this time, the passage between the first stator oil passage 241 and the first oil passage 245 of the plunger groove is cut off, and the passage between the second stator oil passage 242 and the first oil passage 245 of the plunger groove is about to be connected. When the control valve 25 continues to move to the right, the large head 251 at one end of the first stator oil passage 241 continues to penetrate into the first oil passage 245 of the plunger groove, the large head 251 at one end of the second stator oil passage 242 continues to move away from the first oil passage 245 of the plunger groove, the left end of the first oil passage 245 of the plunger groove continues to be in a blocked state, and the right end communicates with the second stator oil passage 242, as Figure 3 shown.

[0059] It should be noted that during processing, for the convenience of processing the first stator oil passage 241 and the second stator oil passage 242. A radial hole that radially penetrates the stator main body 201 can be machined on the circumferential outer surface of the stator main body 201. This radial hole is divided into two sections by the control valve 25. One section close to the central axis of the stator 24 is the first stator oil passage 241 or the second stator oil passage 242, and the section far from the central axis of the stator 24 is the auxiliary hole 247, and the two can be separated by a seal.

[0060] The free travel assembly 26 is used to hold the plunger 27 in check to prevent the plunger 27 from contacting the inner surface of the middle rotor 21 and hindering the rotation of the middle rotor 21 without the pressure of hydraulic oil. The free travel assembly 26 includes a plunger top roller 261 and two springs 262. The plunger top roller 261 passes through the end of the plunger 27 that exceeds the plunger groove 244. The two springs 262 are respectively connected to both ends of the plunger top roller 261, and the two springs 262 are respectively located in two auxiliary holes 247 on both sides of the plunger groove 244. One end of the spring 262 is fixed in the auxiliary hole 247, and the other end is connected to one end of the plunger top roller 261.

[0061] It should be noted that when installing the spring 262, one end of the spring 262 can be first connected to a connecting block, the connecting block is placed into the auxiliary hole 247, and then a bolt or screw is horizontally passed through the auxiliary hole 247 from the outside. When the bolt or screw passes through the auxiliary hole 247, it will pass through the connecting block, thus fixing one end of the spring 262 located in the auxiliary hole 247.

[0062] The two springs 262 should ensure that the pulling force on the plunger 27 meets the following conditions: when the vehicle where the drive axle is located is moving freely, the two springs 262 pull the plunger 27 so that the plunger 27 does not contact the inner surface of the middle rotor 21. To meet the above conditions, in the specific design and manufacture, the centrifugal force of the plunger 27 can be obtained based on data such as the set free travel speed and the outer diameter of the middle rotor 21. According to this centrifugal force, the spring 262 and the position of the spring 262 located in the auxiliary hole 247 are selected so that the movement of the plunger 27 caused by the elongation of the spring 262 under this centrifugal force does not touch the inner surface of the middle rotor 21. Those skilled in the art can calculate the specific dimension values based on physical theorems and specific design requirements, which will not be elaborated here.

[0063] The number of the guide rails 20 is the same as the number of the wave units. The number of the wave units is determined according to the driving torque, rotational speed, and power requirements, and can be flexibly determined in the specific design. The process of oil inlet and outlet in the plunger groove 244 corresponds to one working cycle of the plunger 27. The plunger 27 passes through one wave unit corresponding to one working cycle, and the control valve 25 passes through one guide rail 20 also corresponding to one working cycle of the plunger 27. The opening and closing moments or positions of each end of the first oil passage 245 of the plunger groove are determined by the two end positions of the reciprocating movement of the plunger 27, that is, the upper and lower dead points. In other words, in the specific design, the upper and lower dead point positions of the reciprocating movement of the plunger 27 are first determined. When the plunger 27 is at the dead point position, the control valve 25 is exactly at the position where one end of the first oil passage 245 of the plunger groove is changed from open to closed and the other end is changed from closed to open. The number of the plungers 27 is greater than the number of the wave units. Preferably, the number of the plungers 27 is twice the number of the wave units.

[0064] Based on the above structure, the working principle and process of the present utility model are as follows: The oil inlet pipe 11, the oil return pipe 12, and the oil drain pipe 13 are inserted into the drive axle shaft 1 from the middle of the drive axle shaft 1 towards each end of the drive axle shaft 1. The oil inlet pipe 11, the oil return pipe 12, and the oil drain pipe 13 pass through the drive axle shaft 1 and then are inserted into the main shaft 29. Specifically, a first groove and a second groove are further provided on the inner surface of the stator 24. The first groove, the second groove, and the first stator oil drain passage 243 are all grooves provided on the inner surface of the stator 24, and are all grooves along the circumferential direction of the inner surface of the stator 24. Each stator first oil passage 241 communicates with the first groove, and each stator second oil passage 242 communicates with the second groove. The main shaft 29 is provided with a radial first hole, a second hole, and an oil drain hole. When the stator 24 is sleeved on the main shaft 29, the inner surface of the stator 24 fits the outer surface of the main shaft 29. The first hole communicates with the first groove, the second hole communicates with the second groove, and the oil drain hole communicates with the first stator oil drain passage 243. The first hole, the second hole, and the oil drain hole on the main shaft 29 all communicate with the axial through hole of the main shaft 29. The oil inlet pipe 11, the oil return pipe 12, and the oil drain pipe 13 pass through the axial through hole of the main shaft 29 and are respectively inserted into the first hole, the second hole, and the oil drain hole. At this time, the external oil supply sequentially passes through the oil inlet pipe 11, the first hole, and the first groove and enters each stator first oil passage 241.

[0065] Taking a plunger groove 244 and a plunger 27 in this plunger groove 244 as an example, assume that in the initial state, the stator first oil passage 241 corresponding to this plunger groove 244 communicates with the first oil passage 245 in the plunger groove, and the plunger 27 faces the downward section 2121 of one of the wave units. The hydraulic oil in the stator first oil passage 241 sequentially passes through the first oil passage 245 in the plunger groove and the second oil passage 246 in the plunger groove and then enters the plunger groove 244. The oil in the plunger groove 244 overcomes the elastic force of the spring 262 and pushes the plunger 27. At this time, the plunger 27 contacts the Figure 4 downward section 2121 in and moves in a direction away from the central axis of the middle rotor 21. The plunger 27 pushes the middle rotor 21, so that Figure 4The middle rotor 21 in it rotates clockwise. The middle rotor 21 drives the front end cover rotor 22 and the rear end cover rotor 23 to rotate synchronously, and the connecting flange 6, the steel ring 4 and the tire 5 rotate synchronously, realizing the drive of the tire 5. As the rotor continues to rotate, the passages of the stator first oil passage 241 and the plunger groove first oil passage 245 corresponding to the plunger groove 244 are cut off by the control valve 25, and the stator second oil passage 242 is communicated with the plunger groove first oil passage 245. Under the elastic force of the spring 262, the plunger 27 moves back. The oil in the plunger groove 244 sequentially passes through the plunger groove second oil passage 246, the plunger groove first oil passage 245, the stator second oil passage 242, the second groove, and the second hole on the main shaft 29 and then enters the oil return pipe 12. The process of the oil flowing out of the plunger groove 244 corresponds to the upward section 2122 of the plunger 27 passing through the next wave unit. When the plunger 27 reaches the downward section 2121 of the next wave unit, the stator first oil passage 241 and the plunger groove first oil passage 245 are reconnected, and the above process is repeated, and the plunger 27 can continuously push the middle rotor 21 to rotate clockwise.

[0066] In the initial state, a part of the plungers 27 are facing the downward section 2121, and their stator first oil passages 241 and plunger groove first oil passages 245 are communicated; another part of the plungers 27 are facing the upward section 2122, and their stator second oil passages 242 and plunger groove first oil passages 245 are communicated. At this time, when the stator first oil passage 241 is used as the oil inlet passage, the middle rotor 21 can be pushed to rotate Figure 4 clockwise in it. If in the initial state, a part of the plungers 27 are facing the upward section 2122, and their stator first oil passages 241 and plunger groove first oil passages 245 are communicated; another part of the plungers 27 are facing the downward section 2121, and their stator second oil passages 242 and plunger groove first oil passages 245 are communicated. At this time, when the stator first oil passage 241 is used as the oil inlet passage, the middle rotor 21 can be pushed to rotate Figure 4 counterclockwise in it.

[0067] In a specific case, the initial state of the motor 2 is fixed. When it is necessary to drive the middle rotor 21 to rotate in the reverse direction, the flow direction of the hydraulic oil can be changed. That is, the hydraulic oil enters the motor 2 from the oil return pipe 12 and flows out from the oil inlet pipe 11.

[0068] Finally, it is necessary to state here: The above embodiments are only used to further illustrate the technical solutions of the present invention in detail, and cannot be understood as a limitation on the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all belong to the protection scope of the present invention.

Claims

1. A hydraulic drive axle without an oil distributor, characterized in that It includes a drive axle shaft (1), a motor (2) and a tire (5). The drive axle shaft (1) is a long rod-shaped structure with a hollow interior or a through hole. Each end of the drive axle shaft (1) is connected to a motor (2) and at least one tire (5). The tire (5) is sleeved outside a steel rim (4), and the steel rim (4) is installed on a wheel hub (3). The wheel hub (3) is installed on the drive axle shaft (1) through a bearing. The motor (2) includes a main shaft (29), a rotor, a stator (24), a free travel assembly (26), a plunger (27) and a control valve (25). The main shaft (29) is coaxially connected to the drive axle shaft (1). The stator (24) is fixedly sleeved outside the main shaft (29). The rotor of the motor (2) is installed on the steel rim (4). The stator (24) includes an integrally connected stator main body part (201) and two stator connection parts (202) respectively located on both sides of the stator main body part (201). The stator main body part (201) is provided with a plurality of plunger grooves (244). The plunger grooves (244) are grooves provided on the circumferential outer surface of the stator main body part (201). The plurality of plunger grooves (244) are evenly spaced along the circumferential direction of the stator (24). A plunger (27) is movably arranged in each plunger groove (244). Each plunger groove (244) is equipped with a first oil passage (245) of the plunger groove. The two ends of the first oil passage (245) of the plunger groove are respectively the inlet and outlet of hydraulic oil, and the middle part is communicated with the plunger groove (244). The tire (5) is rotatably sleeved outside the rotor. The rotor includes a middle rotor (21) and two end cover rotors. The two end cover rotors are respectively fixedly connected to the two end faces of the middle rotor (21). The two end cover rotors are respectively sleeved outside the two stator connection parts (202) through bearings. The inner surface (212) of the middle rotor (21) is wavy along the circumferential direction. The plunger (27) contacts the inner surface of the middle rotor (21) and pushes the middle rotor (21) to rotate under the push of the hydraulic oil in the plunger groove (244). A plurality of wavy guide rails (20) located in the same ring are provided on the end face of each end cover rotor facing the other end cover rotor. The concave-convex trends of the guide rails (20) on the two end cover rotors are arranged staggeredly. The control valve (25) includes a connecting rod part (252) and two large head parts (251) thicker than the connecting rod part (252) connected to both ends of the connecting rod part (252). The control valve (25) passes through the first oil passage (245) of the plunger groove. The outer diameter of the connecting rod part (252) is smaller than the aperture of the first oil passage (245) of the plunger groove. The two large head parts (251) can be respectively inserted into and block both ends of the first oil passage (245) of the plunger groove. The two end parts of the control valve (25) respectively contact the guide rails (20) on the two end cover rotors. As the rotor rotates, the guide rails (20) on the two end cover rotors push the control valve (25) to reciprocate to alternately block both ends of the first oil passage (245) of the plunger groove. The free travel assembly (26) prevents the plunger (27) from contacting and driving the inner surface of the middle rotor (21) when the plunger (27) is not under the pressure of hydraulic oil by applying a pulling force to the plunger (27).

2. The hydraulic drive axle according to claim 1, wherein: Each plunger groove (244) is also equipped with a first stator oil passage (241), a second stator oil passage (242), and a second plunger groove oil passage (246). One inlet and outlet of the first stator oil passage (241) is provided on the inner surface of the stator main body (201), and the other inlet and outlet communicates with one end of the first plunger groove oil passage (245). The other end of the first plunger groove oil passage (245) communicates with one end of the second stator oil passage (242). The inlet and outlet at the other end of the second stator oil passage (242) is provided on the inner surface of the stator main body (201). One end of the second plunger groove oil passage (246) communicates with the middle of the first plunger groove oil passage (245), and the other end communicates with the plunger groove (244).

3. The hydraulic drive axle according to claim 2, wherein: One of the first stator oil passage (241) and the second stator oil passage (242) is an oil inlet passage, and the other is an oil outlet passage. Both the first stator oil passage (241) and the second stator oil passage (242) are passages provided in the radial direction of the stator main body (201). The length direction of the first plunger groove oil passage (245) is parallel to the axial direction of the stator (24).

4. The hydraulic drive axle according to claim 1, wherein: The free travel assembly (26) includes a plunger top roller (261) and two springs (262). The plunger top roller (261) passes through one end of the plunger (27) that extends beyond the plunger groove (244). The two springs (262) are respectively connected to both ends of the plunger top roller (261). One end of the spring (262) is fixed on the stator (24), and the other end is connected to one end of the plunger top roller (261).

5. The hydraulic drive axle according to claim 4, wherein: The two springs (262) are respectively located in two auxiliary holes (247) on both sides of the corresponding plunger groove (244).

6. The hydraulic drive axle according to claim 1, wherein: A stator oil drain passage is also provided on the stator main body (201). The stator oil drain passage is used to guide and discharge the leaked hydraulic oil in the motor (2). The stator oil drain passage includes a first stator oil drain passage (243) and a second stator oil drain passage. The first stator oil drain passage (243) is a groove provided on the inner surface of the stator (24). The first stator oil drain passage (243) is arranged in a circle along the circumferential direction of the inner surface of the stator (24). One end of the second stator oil drain passage communicates with the first stator oil drain passage (243), and the port at the other end is provided on the circumferential outer surface of the stator main body (201).

7. The hydraulic drive axle according to claim 6, wherein: A first groove and a second groove are also provided on the inner surface of the stator (24). Both the first groove and the second groove are grooves provided on the inner surface of the stator (24), and both are grooves arranged in a circle along the circumferential direction of the inner surface of the stator (24). Each first stator oil passage (241) communicates with the first groove, and each second stator oil passage (242) communicates with the second groove. The main shaft (29) is provided with a radial first hole, a second hole, and an oil drain hole. When the stator (24) is sleeved on the main shaft (29), the first hole communicates with the first groove, the second hole communicates with the second groove, and the oil drain hole communicates with the first stator oil drain passage (243). The first hole, the second hole, and the oil drain hole on the main shaft (29) all communicate with the axial through hole of the main shaft (29).

8. The hydraulic drive axle according to claim 7, wherein: Insert the inlet pipe (11), the return pipe (12) and the drain pipe (13) from the middle of the drive axle shaft (1) towards each end of the drive axle shaft (1). The inlet pipe (11), the return pipe (12) and the drain pipe (13) pass through the drive axle shaft (1) and then are inserted into the main shaft (29). The drain pipe (13) passes through the axial through-hole of the main shaft (29) and then is inserted into the drain hole. The inlet pipe (11) passes through the axial through-hole of the main shaft (29) and then is inserted into the first hole or the second hole. The return pipe (12) passes through the axial through-hole of the main shaft (29) and then is inserted into the second hole or the first hole.

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