Patent ID: 6513325
Filing Date: 2003-02-04
Classification: B60K,F16H

Abstract:
A hydrostatic transmission immersed in an oil sump formed in a housing, comprising:a hydraulic pump; a hydraulic motor; a center section on which said hydraulic pump and said hydraulic motor are mounted, wherein said center section is formed therein with a pair of oil passages through which said hydraulic pump and said hydraulic motor are fluidly connected with each other, and said center section is provided on an outer surface thereof with a pair of openings of said respective oil passages, a pump capacity changing member for varying the direction and amount of hydraulic fluid discharged from said hydraulic pump to said hydraulic motor through said pair of oil passages in said center section; a control shaft rotatably supported by said housing; a control arm disposed in said housing, said control arm being rotatably centered on said control shaft and engaged with said pump capacity changing member, wherein said pump capacity changing member is moved to various actuation positions including a neutral position in association with rotation of said control arm rotated to various actuation positions including a neutral position; a contact member formed integrally with said control arm, said contact member having a surface abutting against said pair of openings of said center section; a pair of oil passages provided in said contact member, wherein said pair of oil passages in said contact member are shut from said oil sump and open on said surface of said contact member, and wherein said pair of oil passages in said contact member communicate with said respective openings of said center section when said control arm is located in a certain range including said neutral position; and an orifice provided in said contact member so as to connect said pair of oil passages in said contact member with each other.