Effect of Piston Shape on the Lubrication Characteristics of Hydraulic Piston Pump and Motor

피스톤 형상이 유압피스톤 펌프$cdot$모터의 윤활특성에 미치는 영향

Thin film flow in the clearance between cylinder bore and axially moving compositeshape piston is analyzed to study the effect of piston shape on the lubrication characteristics of hydraulic piston pump and motor. It is shown that the piston shape significantly affect the distribution of fluid film pressure, lateral force acting on the piston and leakage flow rate in the clearance. And it is also shown that the composite-shape piston is more effective than the cylindrical piston under tilted condition to reduce the possibility of hydraulic locking. Therefore, the results of present study can be used usefully in the design-and manufacturing of hydraulic piston pump and motor.