Axial piston hydraulic rotating machine

Abstract

PROBLEM TO BE SOLVED: To provide an axial piston hydraulic rotating machine having high stability of a piston shoe. SOLUTION: A circular internal static pressure pocket 23 communicated with a filler opening 9 A, an inner peripheral land portion 22 formed on the outer periphery of the internal static pressure pocket 23, an external static pressure pocket 24 formed on the outer periphery of the inner peripheral land portion 22, and an outer peripheral land portion 25 formed on the outer periphery of the external static pressure pocket 24 are formed on the sliding surface in contact a piston shoe 9 with the swash palate 10. The inner peripheral land portion 22 is annularly formed around the filler opening 9 A. Oil passing grooves 27 through which the internal static pressure pocket 23 communicates with the external static pressure pocket 24 are formed in parts of the inner peripheral land portion 22 on straight lines, passing through the center of the filler opening 9 A. The oil passing grooves 27 are inclined with respect to the straight line A-B passing through the center of the filler opening 9 A. An inner wall surface and an outer wall surface of the inner peripheral land portion 22 are disposed on the straight lines that connect the center of the filler opening 9 A to the center of the oil passing groove 27.

1 . An axial piston hydraulic rotating machine comprising: a rotary shaft; a rotor attached to the rotary shaft; a piston slidably provided in a cylinder hole formed in the rotor; a piston shoe swingably attached to the piston; and a swash plate with which the piston shoe is slidably in contact,
 wherein: filler opening communicated with the cylinder hole via an oil passing hole formed in the piston and an internal static pressure pocket communicated with the filler opening are formed in a sliding surface of the piston shoe with respect to the swash plate;   an inner peripheral land portion, an external static pressure pocket, and an outer peripheral land portion are formed in this sequence concentrically with respect to the filler opening on an outer periphery around the internal static pressure pocket;   an oil passing groove through which the internal static pressure pocket communicates with the external static pressure pocket is formed in a part of the inner peripheral land portion on a straight line that passes through a center of the filler opening; and   a direction of forming the oil passing groove is inclined with respect to a straight line that connects the center of the filler opening to the center of the oil passing groove, and an inner wall surface and an outer wall surface of the inner peripheral land portion are disposed on the straight line that connects the center of the filler opening to the center of the oil passing groove.   
     
     
         2 - 3 . (canceled)