PURPOSE: To support the side force without providing a special supporting means by providing thrust static pressure bearings and radial static pressure bearings so that the moment around a rotary shaft and around the x-axis and y-axis regarding the point of application of force of the resultant force of the average hydraulic reaction force is balanced.
CONSTITUTION: Pistons 10 swayably connected with spherical sections 10A formed at the tip section to a drive disk 6 are inserted into multiple cylinders 9 provided on a cylinder block 8, and the concave end face at one end of the cylinder block 8 is coupled and supported on the convex end face of a valve plate 11. The thrust load component in the average hydraulic reaction force applied to the drive disk 6 and the side force are received by multiple thrust static pressure bearings 20, the radial load component is received by multiple radial static pressure bearings 26 respectively, and these bearings 20, 26 are arranged at the positions where the moment around a rotary shaft and around the x-axis and y-axis regarding the point of application of force of the resultant force of the average hydraulic reaction force is balanced and the positions where the side force is negated.
NAKAMURA ICHIRO
GOTO YASUHARU
