Measured stiffness and displacement coefficients of a stationary rotor hydrostatic bearing

A hydrostatic bearing is described whereby the oil pockets and capillary feeds are incorporated in a stationary central shaft to support an external rotor. Observations are given on general published design recommendations for hydrostatic bearings with which the bearing was designed. Experiments were carried out with the rotor supported and not rotating which appeared to validate performance predicted by the design recommendations, including direct stiffness. It was also found, by invoking recently devised measurement techniques, that the bearing exhibited displacement coefficients, including cross terms, which implied significantly different stiffness values.