Lubrication Condition between the Piston and Cylinder for Low-speed Ranges of Swashplate Type Axial Piston Pumps and Motors (Observation and Evaluation).

Lubrication between the piston and cylinder of a swashplate type axial piston pump or motor affects performance greatly. It is desirable to make fluid lubrication condition in this sliding parts so that to decrease friction and abrasion. Understanding the lubrication condition between the piston and cylinder is very important to make optimal fluid lubrication in wide operating ranges.In this report, degree of metal contact or separation based on fluid film between the piston and cylinder is observed by measuring separation voltage (contact electric resistance) under a constant voltage applied across the piston and cylinder. Further, effects of each operating condition and radial clearance between the piston and cylinder is examined by evaluating lubrication condition using data processing by a personal computer.