Abstract
In this paper, a method to analyze the characteristics of fluid films between a spherical valve plate and a cylinder block of axial piston machines is derived. Since the radius of the spherical surface is much larger than the pitch circle radius of valve plate ports, emphasis is put to clarify the difference between spherical valve plates and traditional plane valve plates. The characteristics discussed are the load carrying capacity and the film coefficients of both elasticity and damping. As a result, it is shown that the spherical valve plate is slightly superior to the plane valve plate.
