Patent ID: 6907729

Claim:
A hydrostatic transmission including a closed fluid circuit, said hydrostatic transmission being contained together with a deceleration gear mechanism in a housing, and said housing being filled with fluid so as to serve as a fluid sump, comprising: a check valve assembly in connection with said closed fluid circuit, said check valve assembly including a vertically movable valve member, a valve seat, and a draining operation member movable perpendicularly to the movement of said valve member, wherein said valve member is lowered by gravity and hydraulic pressure in said closed fluid circuit so as to fit said valve member on said valve seat, thereby sealing said closed fluid circuit, and wherein said valve member is raised apart from said valve seat due to hydraulic pressure in said closed fluid circuit dropping below pressure in said fluid sump, thereby supplying fluid from said fluid sump to said closed fluid circuit, and wherein said valve member is raised apart from said valve seat by movement of said draining operation member, thereby draining fluid from said closed fluid circuit to said fluid sump.