Patent ID: 8806864

Claim:
A transmission comprising: a casing; an output element supported by the casing; a hydrostatic stepless transmission unit disposed in the casing so as to be driven by a drive source disposed outside of the casing, the hydrostatic stepless transmission unit including: a pump shaft configured to be drivingly connected to the drive source; a motor shaft member disposed coaxially to the pump shaft so as to be rotatable relative to the pump shaft, thereby constituting a hydraulic pump and a hydraulic motor centered on the pump shaft and the motor shaft member, wherein an axially distal end of the motor shaft member is disposed on the axially proximal side of an axially distal end of the pump shaft so that axial ends of the pump shaft are the most distal ends of the hydrostatic stepless transmission unit in the axial direction of the pump shaft; a cylinder block fixed on the pump shaft, the cylinder block being formed therein with a pump cylinder hole parallel to the pump shaft, a motor cylinder hole parallel to the pump shaft, and a pair of fluid passages interposed between the pump cylinder hole and the motor cylinder hole; a pump plunger fitted into the pump cylinder; a movable swash plate pressed against the pump plunger; a motor plunger fitted into the motor cylinder hole; and a swash plate provided on the motor shaft member and pressed against the motor plunger; a forward/backward traveling direction selecting unit disposed in the casing so as to transmit power outputted from the hydrostatic stepless transmission unit to the output element, the forward/backward traveling direction selecting unit including: a forward-traveling drive train; a backward-traveling drive train; and a clutch for selecting either the forward-traveling drive train or the backward traveling drive train to transmit the power outputted from the motor shaft member to the output element, wherein the forward/backward traveling direction selecting unit and the output element are entirely disposed between the axial ends of the pump shaft in the axial direction of the pump shaft.