SWASH PLATE TYPE PISTON PUMP MOTOR

PROBLEM TO BE SOLVED: To provide a swash plate type piston pump motor capable of simultaneously accomplishing three merits as securing large the area of the shoe abutting surface of a shoe retainer, preventing the shoe retainer from breakage caused by stress concentration, and setting low the spring constant of each spring part of the shoe retainer. SOLUTION: This pump motor comprises a cylinder block 2, a rotary shaft 6, a piston 4 inserted slidably into a cylinder 2A formed in the block 2, a shoe 3 provided at the end of the piston 4, a swash plate 5 wherewith the shoe 3 makes sliding contact, shoe retainer 1 to retain the shoe 3, and a retainer guide 2A, wherein the shoe retainer 1 is furnished with a through hole 1A to admit insertion of the rotary shaft 6 in the center, a plurality of shoe inserting holes 1B, an abutting part 1E to abut to the retainer guide 2A, spring parts 1D to press the shoe 3 to the swash plate 5, and a plurality of notches 1C to generate communication between the through hole 1A and the shoe inserting holes 1B. Each spring part 1D consists of a part located between two of the notches 1C.