The Lubrication of Overclamped Slippers in Axial Piston Pumps—Centrally Loaded Behaviour

In overclamped axial piston pump slippers only part of the clamping load is carried by the hydrostatic pressures. The remainder has to be supported hydrodynamically and small amounts of non-flatness of the slipper surface are essential for successful operation. It is shown that, under centrally loaded conditions, the operating clearance does not vary greatly with the magnitude or profile of the surface non-flatness, provided that the surface is generally convex. Thus the film thickness under the slipper can be predicted with reasonable accuracy. Measured clearances closely match those calculated theoretically.