Self-lubricating cycloid hydraulic motor

Abstract

The invention relates to the technical field of hydraulic motors, in particular to a cycloid hydraulic motor integrating self-lubricating and cooling functions, which can establish an oil return channel inside to smoothly discharge leaked oil, can take away heat and scrap iron generated by friction of a thrust bearing, and can form oil film lubrication between the front end of a shaft and a shell to ensure normal operation of the motor. The motor comprises a motor body, the motor body is provided with a first oil port and a second oil port, the first oil port and the second oil port are communicated with an internal oil duct, an output shaft is arranged in the motor body, and a thrust bearing and a thrust gasket are arranged between the front end of the output shaft and a shell of the motor body. An oil return channel is arranged between the thrust bearing and a shell of the motor body, an oil return through hole communicated with the oil return channel and the in-shaft counter bore is formed in the output shaft, the oil return channel is communicated with the first oil port and provided with a first one-way valve, and the second oil port is communicated to the peripheral face of the front end of the output shaft through an inner flow channel. The oil return channel communicates with the inner flow channel and is provided with a second one-way valve.

Description

Technical Field

[0001] This invention relates to the field of hydraulic motor technology, specifically to a cycloidal hydraulic motor that integrates self-lubrication and cooling functions. Background Technology

[0002] Hydraulic motors require hydraulic oil during operation, and proper clearances are necessary between motor components for normal operation. Once hydraulic oil enters the motor, it leaks gradually from the high-pressure chamber along these clearances, eventually accumulating inside the shaft and housing. This causes increased internal pressure, preventing drainage and placing additional pressure on the shaft seal, reducing its lifespan and increasing the risk of leakage. Simultaneously, the thrust bearing's rolling friction between the shaft shoulder and thrust washer generates heat and fine metal filings. The heat causes component deformation, affecting fit accuracy, and the metal filings contaminate the motor's cleanliness. Both significantly impact motor performance. Furthermore, the distance between the shaft tip and the high-pressure oil is relatively large, preventing sufficient lubrication and oil film formation. When the motor is subjected to radial force, the shaft tip is prone to seizing against the housing, causing motor failure and rendering it inoperable.

[0003] Therefore, some companies are currently using the following technical means: 1. Connect the external drain port of the hydraulic motor to the oil pipe, and connect the drain pipe to the return oil circuit; 2. Increase the frequency of motor maintenance. After a period of use, disassemble the motor, clean it thoroughly, and replace the thrust bearing and thrust washer. 3. Do not use this model of motor in applications with radial force, or only when it is subjected to a small radial force.

[0004] Each of the above methods has some problems, such as increasing the space occupied by the motor, having strict requirements for the application scenario, having a limited scope of application, and increasing the maintenance frequency will increase maintenance costs. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a self-lubricating cycloidal hydraulic motor, which can establish an internal oil return channel to allow leaked oil to be discharged smoothly, and can also remove the heat and iron filings generated by the friction of the thrust bearing, and can also form an oil film lubrication between the front end of the shaft and the housing to ensure the normal operation of the motor.

[0006] The technical solution is as follows: A self-lubricating cycloidal hydraulic motor includes a motor body, on which are provided an oil port 1 and an oil port 2, which are connected to an internal oil passage. An output shaft is provided inside the motor body, and a thrust bearing and a thrust washer are provided between the front end of the output shaft and the housing of the motor body. The characteristic feature is that an oil return channel is provided between the thrust bearing and the housing of the motor body. An oil return through hole is provided on the output shaft, which is connected to the oil return channel and the inner countersunk hole of the shaft. The oil return channel is connected to the oil port 1 and is provided with a one-way valve 1. The oil port 2 is connected to the outer peripheral surface of the front end of the output shaft through an internal flow channel. The oil return channel is connected to the internal flow channel and is provided with a one-way valve 2.

[0007] By adopting this invention, an internal oil return channel is added, allowing internally leaking oil to enter the oil return channel through the oil return through hole, and finally be discharged from the oil outlet of the hydraulic motor through the one-way valve. At the same time, the oil continuously flushes away the heat and iron filings generated by the friction of the thrust bearing, improving the motor performance. In addition, an internal flow channel is added, which can lead the hydraulic oil to the front end of the output shaft. The hydraulic pressure difference fills the space between the front end of the shaft and the housing with lubricating oil, forming an oil film lubrication to ensure the normal operation of the motor. Attached Figure Description

[0008] Figure 1 Front view of the hydraulic motor; Figure 2 Top view of the hydraulic motor; Figure 3 Right view of the hydraulic motor (with CC section line); Figure 4 for Figure 3 Central CC-direction profile Figure 2 (Internal schematic diagram of the present invention); Figure 5 Right view of the hydraulic motor (with DD section line); Figure 6 for Figure 5 Cross-sectional view along the DD direction. Detailed Implementation

[0009] See Figures 1 to 6 As shown, a self-lubricating cycloidal hydraulic motor includes a motor body 1. The motor body 1 has an oil port 2 and an oil port 3. The oil port 2 and the oil port 3 are connected to an internal oil passage. When the oil port 2 is the oil inlet, the hydraulic oil enters from the oil port 2, passes through the internal oil passage, and flows out from the oil port 3, which is the oil outlet. Conversely, when the oil port 3 is the oil inlet, the hydraulic oil enters from the oil port 3, passes through the internal oil passage, and flows out from the oil port 2, which is the oil outlet.

[0010] An output shaft 4 is installed inside the motor body 1. A thrust bearing 5 and a thrust washer 6 are installed between the front end of the output shaft 4 and the housing of the motor body 1. An oil return channel 7 is installed between the thrust bearing 5 and the housing of the motor body 1. An oil return through hole 9 is opened on the output shaft 4, which connects the oil return channel 7 and the inner countersunk hole 8. The oil return channel 7 is connected to oil port 2 and is equipped with a one-way valve 10. The flow direction of the one-way valve 10 is from the oil return channel 7 to oil port 2. Oil port 3 is connected to the outer peripheral surface of the front end of the output shaft 4 through the inner flow channel 11. The oil return channel 7 is connected to the inner flow channel 11 and is equipped with a one-way valve 12. The flow direction of the one-way valve 12 is from the oil return channel 7 to the inner flow channel 11.

[0011] When oil port 3 is used as the oil inlet, the front end of the output shaft 4 is far from the oil port. Furthermore, the clearance between the housing and the shaft is very small (diameter clearance within 0.03 mm), resulting in insufficient lubrication of the front end of the output shaft 4. See... Figure 5 As shown, this invention adds an inner flow channel 11 to guide the high-pressure oil from oil port 2 3 to the front end of the output shaft 4. Due to the leakage from high pressure to low pressure, the gap between the front end of the shaft and the housing is filled with oil, ensuring that the entire shaft and housing can work better as a set of sliding bearings.

[0012] The internal oil return process of the motor is as follows: When oil port 2 is the inlet and oil port 3 is the outlet, hydraulic oil enters from oil port 2, which is the high-pressure side. Due to the presence of check valve 10 and the fact that hydraulic oil does not flow from the low-pressure side to the high-pressure side, no hydraulic oil flows through check valve 10. After the hydraulic oil enters the internal oil passage of the motor, it flows out from oil port 3. The internal leakage oil flows into the inner countersunk hole 8 through the spline and clearance at the end of the linkage shaft 13, and then enters the return oil passage 7 through the gap between the return oil passage 9, the thrust bearing 5 and the thrust washer 6. Finally, it enters the inner flow passage 11 through check valve 12 and finally flows out from oil port 3.

[0013] When oil port 23 is the inlet and oil port 12 is the outlet, hydraulic oil enters from oil port 23 and splits into two paths. One path enters the internal oil passage, and the other path flows to the internal flow passage 11, reaching the front end of the output shaft 4 for lubrication. This is the high-pressure side. Due to the presence of check valve 212 and the fact that hydraulic oil does not flow from the low-pressure side to the high-pressure side, no hydraulic oil flows through check valve 212. The hydraulic oil that enters the internal oil passage flows out from oil port 12, while the internal leakage oil flows into the inner countersunk hole 8 through the spline and clearance at the end of the linkage shaft 13. Then, it enters the return oil passage 7 through the gap between the return oil through hole 9, the thrust bearing 5, and the thrust washer 6, and finally enters oil port 12 through check valve 10 and flows out.

[0014] Hydraulic motors can change direction by altering the oil inlet direction. When the motor reverses direction, the previous outlet becomes the inlet. However, due to the presence of a check valve, the high-pressure oil at the inlet will not flow back through the aforementioned return channel; instead, it will be blocked by the check valve. Since check valve channels are installed between both oil ports of the motor and the housing cavity, the return channel can operate normally, directing internal leakage to the current outlet.

[0015] In summary, regardless of the motor's direction of rotation, a channel can be established from internal leakage to the oil return port. Furthermore, this channel passes through the thrust bearing, directing heat and wear debris from that area to the oil outlet, extending the motor's service life. The shaft seal is located within the housing cavity, ensuring that the pressure at the shaft seal is the same as the pressure at the oil outlet, improving the shaft seal's working conditions and significantly reducing the risk of oil leakage.

Claims

1. A self-lubricating gerotor hydraulic motor comprising a motor body, an oil port one and an oil port two are formed on the motor body, the oil port one and the oil port two communicate with an internal oil passage, an output shaft is arranged in the motor body, a thrust bearing and a thrust washer are arranged between the front end of the output shaft and the housing of the motor body, characterized in that, The thrust bearing is provided with an oil return channel between the housing of the motor body, the output shaft is provided with an oil return through hole which communicates the oil return channel and the inner hole of the shaft, the oil return channel is communicated with the oil port one and provided with a one-way valve one, the oil port two is communicated to the front end outer circumferential surface of the output shaft through an inner flow channel, the oil return channel is communicated with the inner flow channel and provided with a one-way valve two.

Images