Hydrostatic transmission with pressure regulation means

摘要

A hydrostatic transmission comprising a housing formed with a fluid sump, a center section, a hydraulic pump, and a hydraulic motor. A fluid passage is formed in the center section. A bore is open at an outer surface of the center section in communication with the fluid passage. An output operation device is provided for controlling discharged fluid of the hydraulic pump. A piston having an outer surface is reciprocally inserted into the bore so as to be allowed to project outward from the center section. A valve is disposed within the bore. The valve is biased to be closed by a spring disposed between the valve and the piston. A member interlocks with the output operation device so as to contact with the outer surface of the piston.