Transmission structure of stepless speed change hydraulic motor

Abstract

The utility model relates to a transmission structure of a stepless speed change hydraulic motor, which comprises a cylinder body and a working shaft, the working shaft is rotatably connected in the cylinder body, an outer shaft body of the working shaft is sleeved with a pressure spring, one end of the pressure spring is abutted against the bottom surface of an outer spline of the working shaft, and the other end of the pressure spring is abutted against the cylinder body. By arranging the compression spring structure, the reset capacity and the transmission stability of the working shaft are effectively enhanced, the number of parts is reduced through structure simplification, assembly and maintenance are convenient, and the reliability and the production efficiency of the whole system are improved. The HST hydraulic motor solves the technical problems that in an existing HST hydraulic motor structure, a cylinder body and a return sleeve are connected in a split mode, so that supporting stability is poor, the bearing capacity of a deep groove ball bearing is insufficient, and the assembly technology is complex.

Description

TECHNICAL FIELD

[0001] The utility model relates to a transmission structure of stepless speed change hydraulic motor. BACKGROUND

[0002] In modern agricultural machinery, HST (hydrostatic transmission) system has been widely applied to many small and medium-sized devices, including rice transplanter, harvester and orchard operation vehicle, due to its strong stepless speed change ability, compact structure, sensitive control and other advantages. The HST hydraulic stepless speed changer is usually composed of a variable displacement pump, a fixed displacement motor and an oil supplement pump, forming a closed hydraulic circulation system, and the stepless adjustment of power is realized by controlling the displacement of the variable displacement pump to adapt to the driving demand under different working conditions.

[0003] In the prior art, the pump and motor transmission structure of such system is mostly composed of an input shaft, a cylinder body, a return sleeve, a plurality of supporting rods, a spring and a bearing. The cylinder body and the return sleeve are usually designed in a split body and connected and positioned by three or more supporting rods. This structure has a certain stability problem in long-term operation. Especially under high load or frequent start-stop working conditions, the supporting rods are prone to micro deformation or loosening, which affects the transmission accuracy of the whole machine and the service life of the system. In addition, although the deep groove ball bearing commonly used in this structure is suitable for bearing radial load, there is also a large axial load in the motor system, and the carrying capacity of the deep groove ball bearing is difficult to meet the actual demand, which easily leads to premature wear or failure.

[0004] At the same time, due to the plurality of connecting components involved in the above structure, the overall assembly process is complex, the number of parts is large, and the machining precision is high, which not only increases the manufacturing cost, but also limits the automation assembly efficiency and batch production capacity. With the increasing requirements of agricultural equipment industry on product reliability, lightweight and cost control, the traditional HST hydraulic motor structure gradually exposes the problems of complex structure, low installation efficiency and insufficient carrying capacity. Therefore, it is urgent to optimize the design of the core transmission structure, starting from the aspects of structure integration, stress path and material selection, to realize the technical breakthrough of high reliability, modularization and low cost. Utility model content:

[0005] The utility model aims at solving the above technical problems, and provides a transmission structure of stepless speed change hydraulic motor.

[0006] A transmission structure of stepless speed change hydraulic motor, comprising a cylinder body and a working shaft, the working shaft is rotatably connected in the cylinder body, a compression spring is sleeved on the outer side shaft body of the working shaft, one end of the compression spring abuts against the bottom surface of the outer side spline of the working shaft, and the other end of the compression spring abuts against the cylinder body.

[0007] Further, the working shaft is sleeved with a return sleeve outside, one part of the return sleeve is connected with the working shaft, and the other part is connected with the cylinder body.

[0008] Further, the return sleeve is integrally formed with the cylinder body.

[0009] Further, the two ends of the compression spring are provided with a first spring seat and a second spring seat, the first spring seat is abutted on the bottom surface of the spline, and the second spring seat is abutted on the baffle plate, and the baffle plate is embedded on the inner side wall connected between the cylinder body and the outer side surface of the working shaft.

[0010] Further, the working shaft is rotatably connected in the cylinder body through a bearing.

[0011] Further, the bearing is a tapered roller bearing.

[0012] Further, the cylinder body is of a split structure, comprising a cylinder base and a cylinder cover.

[0013] Beneficial effects: compared with the prior art, the utility model has the following advantages:

[0014] The utility model discloses a transmission structure of stepless speed change hydraulic motor, which is characterized by the following technical scheme.

[0015] Secondly, the utility model discloses a transmission structure of stepless speed change hydraulic motor, which is characterized by the following technical scheme.

[0016] In addition, the tapered roller bearing is used to replace the deep groove ball bearing at the key position, and the system carrying capacity is significantly enhanced.

[0017] As a whole, the technical scheme of the utility model ensures the transmission performance, reduces the manufacturing and maintenance cost, improves the product standardization and batch production adaptation ability, is especially suitable for the small and medium-sized agricultural machinery with high reliability and assembly efficiency requirement, and helps to promote the further popularization and technical upgrading of the HST hydraulic system in the agricultural equipment field. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic view of the transmission structure in the embodiment;

[0019] Figure 2 is Figure 1 is a partial enlarged view of A in the figure;

[0020] Figure 3 is a schematic view of the transmission structure in the prior art;

[0021] Figure 4 is Figure 3 is a partial enlarged view of B in the figure;

[0022] In the figure, 1 is a working shaft, 2 is a compression spring, 3 is a spline, 4 is a first spring seat, 5 is a second spring seat, 6 is a baffle, 8 is a return sleeve, 9 is a cylinder cover, 10 is a cylinder base, and 11 is a support rod. DETAILED DESCRIPTION

[0023] In order to deepen the understanding of the utility model, the utility model will be further described in combination with the embodiment and the drawings below, and the embodiment is only used for explaining the utility model and does not constitute the limitation on the protection scope of the utility model.

[0024] A transmission structure of a continuously variable hydraulic motor comprises a cylinder body and a working shaft 1, the working shaft 1 is rotationally connected in the cylinder body, a compression spring 2 is sleeved on the outer side shaft body of the working shaft 1, one end of the compression spring 2 abuts against the bottom surface of a spline 3 on the outer side of the working shaft 1, and the other end of the compression spring 2 abuts against the cylinder body.

[0025] The transmission structure is used in a continuously variable hydraulic motor system, a compression spring 2 is arranged on the outer side of the working shaft 1, the compression spring 2 provides a constant axial pre-tightening force in the running process, and axial displacement and clearance are effectively inhibited. The working shaft 1 is arranged in the cylinder body and is supported by a bearing, so that the working shaft 1 can stably rotate relative to the cylinder body. The spline 3 is designed to be used as a thrust reference surface for the compression spring 2 when the compression spring 2 is stressed, and the other end of the compression spring 2 is positioned by cooperating with the structure of the cylinder body. The arrangement omits the traditional multi-support rod 11 structure, and does not need an additional support rod 11 to be connected with the compression spring 2, so that the transmission shaft still maintains a stable rotary center in the compression state.

[0026] Through the above structural configuration, the transmission structure of the utility model significantly reduces the number of components and connection nodes while ensuring reliability, the overall structure is more compact, which is conducive to improving the machining consistency and the whole machine assembly efficiency. At the same time, due to the adoption of the elastic pre-tightening mode, the axial impact caused by load change can be effectively absorbed, the stability of system operation and the axial positioning accuracy are improved, and then the service life of the key components is prolonged.

[0027] In a possible implementation, the working shaft 1 is sleeved with a return sleeve 8, one part of the return sleeve 8 is connected with the working shaft 1, and the other part is connected with the cylinder body.

[0028] In a possible implementation, the return sleeve 8 is integrally formed with the cylinder body, so that the connection interface is minimized, the possible gap, loose bolt or stress concentration point is eliminated, and the mechanical strength and stability of the whole machine operation are improved. In the case where the precision requirement is high, the return sleeve 8 and the cylinder body can adopt the coaxial machining process to ensure that the assembly tolerances are consistent, which is helpful to improve the sealing performance and service life of the hydraulic system.

[0029] The integrated design simplifies the machining and assembly process, saves the manufacturing process time, and improves the overall rigidity and fatigue resistance of the structure, which is especially suitable for the scene of the hydraulic motor with high requirements for size compactness and high durability.

[0030] In a possible implementation, the two ends of the compression spring 2 are provided with a first spring seat 4 and a second spring seat 5, the first spring seat 4 abuts against the bottom surface of the spline 3, and the second spring seat 5 abuts against the baffle plate 6 which is embedded in the inner side wall connected between the cylinder body and the outer side surface of the working shaft 1.

[0031] In this embodiment, in order to realize uniform transmission and limiting of the stress at both ends of the compression spring 2, the first spring seat 4 and the second spring seat 5 are independently arranged, so that the compression spring 2 always maintains an axial centering state. The first spring seat 4 is sleeved on the shaft section of the spline 3 through the inner hole positioning, so as to ensure the consistent relative movement with the working shaft 1; the second spring seat 5 is positioned by the fixed baffle plate 6 and abuts against the inner side limiting step of the cylinder body, so as to realize the closed guidance of the spring.

[0032] The arrangement is helpful to reduce the deflection and friction of the compression spring 2 during the working process, and improve the spring life and pre-tightening force stability. The spring seat and the baffle plate 6 can be designed to be detachable for easy maintenance and replacement. The material can be selected from hard aluminum alloy, stainless steel or nylon injection molding parts, and can be flexibly configured according to the spring stiffness and working conditions.

[0033] In a possible implementation, the working shaft 1 is rotatably connected in the cylinder body through a bearing.

[0034] This implementation structure ensures that the working shaft 1 realizes high-precision rotary support in the cylinder body. The bearing is installed in the pre-set bearing seat hole of the cylinder body and forms an interference fit or axial limit with the working shaft 1, so that it remains stable in rotation under high-speed or variable load working conditions. This structure guarantees the coaxiality requirement of the transmission system, effectively suppresses vibration and eccentric wear, and prolongs the service life of the working shaft 1 and related connecting components.

[0035] To meet different operating conditions, different specifications and types of bearings can be selected according to the shaft diameter, load and speed requirements, such as single-row deep groove ball bearings, cylindrical roller bearings or angular contact ball bearings.

[0036] In one possible implementation, the bearing is a tapered roller bearing.

[0037] The use of tapered roller bearings provides enhanced bearing support for the transmission structure, and the tapered structure allows it to simultaneously withstand large axial and radial loads. Compared with traditional deep groove ball bearings, this type of bearing has better rigidity and load capacity when bearing combined torque, and is suitable for high-speed and heavy-load hydraulic motor application scenarios.

[0038] Limiting rings or adjusting shims can be provided at both ends of the bearing to adjust the preload and improve installation consistency. To improve bearing life, high-quality grease or a centralized lubrication system can be used for grease replenishment.

[0039] In one possible implementation, the cylinder body is a split structure, including a cylinder base 10 and a cylinder cover 9.

[0040] This scheme designs the cylinder body as a split structure, with the cylinder base 10 and the cylinder cover 9 connected as a whole by threads, positioning pins and sealing washers. This structure helps to reduce the overall machining difficulty and improve the machining accuracy of critical parts, and is particularly suitable for large-size or segmented machining structures. The cylinder cover 9 can be disassembled, facilitating later maintenance and replacement of internal parts.

[0041] The joint surface between the cylinder base 10 and the cylinder cover 9 can be provided with sealing structures such as O-rings, sealing glue or metal sealing pads to ensure the working sealing performance of the hydraulic system. High-strength bolts, torque locking nuts and other fasteners are selected for the connection method according to the pressure rating to improve the overall operation safety.

[0042] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A transmission structure of a continuously variable hydraulic motor, characterized by comprising: The cylinder body, the working shaft, the compression spring, the return sleeve and the cylinder body are connected together.

2. A continuously variable transmission hydraulic motor according to claim 1, wherein The return sleeve is integrally formed with the cylinder body.

3. A continuously variable transmission hydraulic motor according to claim 2, wherein The two ends of the compression spring are provided with a first spring seat and a second spring seat.

4. A continuously variable transmission hydraulic motor according to claim 1, wherein The working shaft is rotatably connected in the cylinder body through a bearing.

5. A continuously variable transmission hydraulic motor according to claim 1, wherein The bearing is a tapered roller bearing.

6. A continuously variable transmission hydraulic motor according to claim 5, wherein The cylinder body is a split structure, which comprises a cylinder base and a cylinder cover.

7. A continuously variable transmission hydraulic motor according to claim 1, wherein ​

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