Design and Optimization of Self-Compensation Oil Distributor for Hydraulic Motors

Due to high-power output (several thousand kW), hydraulic motors have been widely used in various types of large machinery, such as ships, dredgers, shield machines, and shredders. The oil distributor is a key component that can control the flow direction of inputting high-pressure oil and outputting low-pressure oil for the hydraulic motors to ensure their normal operation. However, there exist substantial challenges in solving the problems of the evident oil leak and power loss in the matching interface between the fixed oil distributor and the rotating cylinder block. For that, this study introduces a self-compensation oil distributor (SCOD), which can auto-adjust the interface spacing by adding balancing pistons and floating seal sleeves, thereby decreasing the oil leakage and the power loss caused by long-term interface wear and inevitable separating force. The balancing pistons and floating seal sleeves can provide a clamping force to balance the interface separating force with the help of hydraulic pressure and springs. Then, a theoretical model is developed to evaluate the oil leakage and power loss characteristics of the SCOD. Based on the model, the gap size between the balancing piston and the oil distributor, a significant parameter for the SCOD, is investigated and optimized. The results indicate that the experimental results show good agreement with the model predictions, and the preferable gap size of 5
μ
m is obtained to ensure low oil leakage and power loss of hydraulic motors. The presented SCOD offers a feasible way to develop high-efficient hydraulic motors.