The Critical Speed of Slipper Bearings in Axial Piston Swash Plate Type Pumps and Motors

A stationary model is adopted to determine the criticalcondition for which the slipper moves away from the swashplatein an axial piston machine. The aim of the analysis is to find thecritical speed, i.e. the value of the machine speed for which theslipper moves away from the swashplate; usually this conditionmay determine bad operating behaviour of the machine, althougha retainer plate is used to maintain the slipper sufficiently near tothe swashplate.The influences of the pressure transition in the cylinder, theswashplate angle and the radial clearance between piston andcylinder on the critical speed are depicted. Successively, the roleof the position of the point of application of the resultant forcedue to the slipper-retaining plate contact is analyzed.