Abstract: A powertrain module for a zero turn radius vehicle, such as a tractor or mower, the powertrain module generally including a structural member or mounting plate to which an engine, a pair of hydrostatic transmission modules, and a pair of axle drive units are attached to form a self-contained powertrain module which may be shipped as a single packaged unit for installation into the zero turn radius implement. The mounting plate provides structural rigidity between the powertrain components attached thereto, and the mounting plate of the powertrain module may be attached directly to the frame of the vehicle, or alternatively, may itself serve as a structural frame member for the vehicle.

Abstract: A hydrostatic transmission including a fluid motor and a variable displacement fluid pump in fluid communication with the motor and having a first and a second, greater, fluid displacement rate. The pump is mounted on a block having an outer surface, a passage through which fluid flows from the pump to the motor, and a first and a second fluid bleed hole extending from the passage to the outer surface. The passage and a sump external to the pump are in fluid communication through the bleed holes and the void of a sliding element disposed within a bore in the block when the pump is operating at its first rate and the sliding element is in a first position. The first bleed hole and the sump are substantially out of fluid communication when the pump is operating at its second rate and the sliding element is in a second position.

Abstract: A transmission including an input, an output, a housing in which the input and output are operatively coupled and containing a quantity of fluid, and an outwardly flowing check valve in fluid communication with the interior of the housing. The check valve is biased into a closed position, and the transmission is substantially sealed when the check valve is in its closed position, whereby leakage of fluid from the transmission is prevented regardless of transmission orientation. The check valve has an open position when the fluid in the housing is pressurized to a predetermined level, whereby the pressurized fluid may be vented from the transmission.

Abstract: A walk-behind self-propelled implement, such as a snow thrower or lawnmower, for example, is provided. The implement includes first and second transmission modules associated with a common single axle to which a pair of drive wheels is attached. The first and second transmission modules are operable exclusively with respect to one another to drive the axle and the wheels in a forward and reverse direction, respectively. A control member mounted to the handle of the implement includes a forward bail member pivotable to rotate the control member in a first direction to urge the wheel to rotate in a forward direction, and a reverse bail member pivotable to rotate the control member in a second direction opposite the first direction to urge the wheel to rotate in a reverse direction.

Abstract: A powertrain module for a zero turn radius vehicle, such as a tractor or mower, the powertrain module generally including a structural member or mounting plate to which an engine, a pair of hydrostatic transmission modules, and a pair of axle drive units are attached to form a self-contained powertrain module which may be shipped as a single packaged unit for installation into the zero turn radius implement. The mounting plate provides structural rigidity between the powertrain components attached thereto, and the mounting plate of the powertrain module may be attached directly to the frame of the vehicle, or alternatively, may itself serve as a structural frame member for the vehicle.

Abstract: A hydrostatic transmission including a fluid motor and a variable displacement fluid pump in fluid communication with the motor and having a first and a second, greater, fluid displacement rate. The pump is mounted on a block having an outer surface, a passage through which fluid flows from the pump to the motor, and a first and a second fluid bleed hole extending from the passage to the outer surface. The passage and a sump external to the pump are in fluid communication through the bleed holes and the void of an sliding element disposed within a bore in the block when the pump is operating at its first rate and the sliding element is in a first position. The first bleed hole and the sump are substantially out of fluid communication when the pump is operating at its second rate and the sliding element is in a second position.

Abstract: A hydrostatic transaxle having a hydrostatic transmission module including a transmission housing, a rotating fluid pump and a rotatable fluid motor, the pump being of variable displacement, the motor being rotated at various speeds and in forward and reverse directions in response to changes in pump displacement; an axle drive unit including a housing and a speed reduction gear train having an input and an output disposed in the axle drive housing, the motor being operably coupled to the gear train input; a differential assembly having a rotating casing, the rotating casing being external to the transmission housing and axle drive unit housing; and a pair of axles extending from the differential assembly casing.