Modelling of the Micro Lubricating Gap Geometry Between Valve Plate and Cylinder Block in an Axial Piston Pump

The paper focuses on the effect of force and torque balance (FTB) of cylinder block, coaxiality error (CE) between main shaft and cylinder block, and other factors, especially eccentric wear (OTEW) of valve plate on wedge angle of the micro lubricating gap between valve plate and cylinder block, and a novel trigonometric function model of the gap geometry and mechanical balance equations of cylinder block are proposed. The three eddy current displacement sensors are used to measure the gap thickness. The results show that, the theoretical wedge angle due to FTB is nearly 1.2E-4, the test wedge angle owing to CE 1.65E-4 similar to 4.3E-4, the wedge angle by OTEW about 1.35E-3, therefore, CE and OTEW have a larger impact on the wedge angle. The test results demonstrate the total wedge angle obviously increases with the enlargement of swash plate angle but slightly rises with the increasing working pressure.