Abstract: A hydraulic motor assembly having a motor and gear reduction set mounted in a housing. The housing may be formed of separate components, including the external surface of the ring gear and the hydraulic motor port block. The motor assembly may also include pressure relief valves or neutral valves in the motor port block and a brake assembly mounted in the port block or on the motor housing to provide braking for the output axle.

Abstract: A hydrostatic transmission may be placed in a free-wheeling state by rotating a bypass actuator that lifts the motor from a motor running surface whereby hydraulic fluid flows into a transmission cavity. A bypass arm connected to the bypass actuator and to a bypass rod may be used to engage and disengage the bypass actuator via operation of the rod. Further, a bypass latch may be used to lock the bypass arm in an engaged position whereby the bypass actuator is engaged and the transmission is disengaged. The bypass latch arm is preferably linked to the brake pedal whereby actuation of the brake pedal disengages the bypass actuator through operation of the latching arm. The system may be designed to provide dynamic braking through transmission resistivity prior to application of a brake force to the axles or wheels by unlatching the bypass arm prior to actuating the brake arm.

Abstract: A bypass mechanism is provided for use in a hydrostatic transmission, to enable the user to open or close a valve between the two pressure sides of the hydraulic circuit of the transmission. An electrical mechanism is positioned to open or close the valve based on a signal which may be generated by a switch associated with the hydrostatic transmission.

Abstract: A transmission mounted in a housing and including a hydrostatic pump and motor mounted on a center section, and a filter connected thereto to prevent contaminants from entering the hydrostatic system. A filter member is mounted to the center section and houses the filter.

Abstract: A transaxle having a transmission housing forming a hydraulic sump and a hydrostatic transmission mounted in the sump. The hydrostatic transmission comprises a center section having hydraulic porting mounted therein and a pair of hydraulic pumps and hydraulic motors mounted on the center section. A first axle housing is mounted on one end of the transmission housing, and has a first output axle mounted therein and connected to one of the hydraulic motors and a second axle housing is mounted on the opposite end of the transmission housing, and has a second output axle mounted therein and connected to the second hydraulic motor. A vehicle incorporating a dual hydrostatic transaxle is also disclosed.

Abstract: A hydrostatic transmission may be placed in a free-wheeling state by rotating a bypass actuator that lifts the motor from a motor running surface whereby hydraulic fluid flows into a transmission cavity. A bypass arm connected to the bypass actuator and to a bypass rod may be used to engage and disengage the bypass actuator via operation of the rod. Further, a bypass latch may be used to lock the bypass arm in an engaged position whereby the bypass actuator is engaged and the transmission is disengaged. The bypass latch arm is preferably linked to the brake pedal whereby actuation of the brake pedal disengages the bypass actuator through operation of the latching arm. The system may be designed to provide dynamic braking through transmission resistivity prior to application of a brake force to the axles or wheels by unlatching the bypass arm prior to actuating the brake arm.

Abstract: A transmission mounted in a housing and including a hydrostatic pump and motor mounted on a center section, having a motor shaft engaged to and driven by the hydraulic motor. An axle may also be mounted in the housing. The center section is secured to the housing using a plurality of bolts or other fasteners having a longitudinal axis parallel to the motor shaft and for the axle.

Abstract: A hydrostatic transaxle having a housing forming a sump containing hydraulic fluid, a charge pump or auxiliary pump in flow communication with the sump for creating high pressure hydraulic fluid from the hydraulic fluid, a center section having hydraulic porting formed therein, a hydraulic pump and motor, connected to the hydraulic pump through the hydraulic porting. A differential and output axles are also mounted in the housing with a drive train connecting the hydraulic motor output shaft and the differential. The drive train comprises a counter shaft secured to the housing and having a first gear engaged to the motor output shaft and a second gear engaged to both the first gear and the differential.

Abstract: A transaxle drive differential assembly powered by an input drive and connected to a pair of axle shafts. The differential assembly includes a housing comprised of a first housing section and a second housing section wherein at least one of the housing sections has a bearing surface. A ring gear, drivingly linked to the input drive, has an inner circumference which is supported on the bearing surface and may have a carrier plate integrally formed therewith. A differential is drivingly linked to the ring gear and is adapted to drive the pair of axle shafts.

Abstract: A method for providing a bypass for a hydraulic circuit in a hydrostatic transmission enables the user to open or close a bypass between the hydraulic circuit of the transmission and a hydraulic fluid sump. The method uses an electromechanical valve mechanism, and provides an electrical signal thereto to open the bypass and divert the hydraulic fluid from the circuit to the sump.

Abstract: An integrated hydrostatic transaxle including a housing in which a center section is supported. The center section supports a hydraulic pump unit and a hydraulic motor unit having a motor shaft drivingly connected thereto. A gear differential assembly is drivingly linked to the motor shaft and is used to drive a pair of axle shafts, which are supported by the housing. The differential assembly includes a mechanism to prevent relative motion of the axle shafts with respect to each other, known as a differential lock mechanism.

Abstract: A transmission mounted in a housing and including a hydrostatic pump and motor mounted on a center section, having a motor shaft engaged to and driven by the hydraulic motor. An axle may also be mounted in the housing. The center section is secured to the housing using a plurality of bolts or other fasteners having a longitudinal axis parallel to the motor shaft and for the axle.

Abstract: A hydrostatic transmission. The hydrostatic transmission generally comprises a sump containing hydraulic fluid, a charge pump in flow communication with the sump for creating high pressure hydraulic fluid from the hydraulic fluid, a center section having hydraulic porting formed therein, a hydraulic pump, a hydraulic motor drivingly connected to the hydraulic pump through the hydraulic porting, and a manifold defining a gallery for storing the high pressure fluid. The gallery is in flow communication with the charge pump and the hydraulic porting.

Abstract: In a hydrostatic transmission or similar axle driving device, a bearing is used to support an axle in a separate axle chamber in the housing, and the bearing has an opening or lobe formed on the outer periphery thereof to allow fluid to flow from a chamber where the axle is housed and a separate chamber in the housing.

Abstract: A hydrostatic transmission may be placed in a free-wheeling state by rotating a bypass actuator that lifts the motor from a motor running surface whereby hydraulic fluid flows into a transmission cavity. A bypass arm connected to the bypass actuator and to a bypass rod may be used to engage and disengage the bypass actuator via operation of the rod. Further, a bypass latch may be used to lock the bypass arm in an engaged position whereby the bypass actuator is engaged and the transmission is disengaged. The bypass latch arm is preferably linked to the brake pedal whereby actuation of the brake pedal disengages the bypass actuator through operation of the latching arm. The system may be designed to provide dynamic braking through transmission resistivity prior to application of a brake force to the axles or wheels by unlatching the bypass arm prior to actuating the brake arm.

Abstract: A transaxle drive differential assembly powered by an input drive and connected to a pair of axle shafts. The differential assembly includes a housing comprised of a first housing section and a second housing section wherein at least one of the housing sections has a bearing surface. A ring gear, drivingly linked to the input drive, has an inner circumference which is supported on the bearing surface. A differential is drivingly linked to the ring gear and is adapted to drive the pair of axle shafts.

Abstract: A bypass mechanism is provided for use in a hydrostatic transmission, to enable the user to open or close a bypass between the hydraulic circuit of the transmission and a sump. The invention also comprises a safety mechanism to prevent excessive freewheeling of the vehicle by providing a plate or other bypass mechanism which engages a valve. The plate or other mechanism is moveable between a first position where the valve opens the hydraulic circuit to the sump and a second position where the valve closes the hydraulic circuit, and a spring mechanism enables the valve to override the bypass mechanism and force the circuit closed under excessive pressure.

Abstract: A transmission mounted in a housing and including a hydrostatic pump and motor mounted on a center section, having a motor shaft engaged to and driven by the hydraulic motor. An axle may also be mounted in the housing. The center section is secured to the housing using a plurality of bolts or other fasteners having a longitudinal axis parallel to the motor shaft and for the axle.

Abstract: A improved differential design intended for use in a vehicle, such as a tractor using a hydrostatic transmission. The differential has a ring gear with an opening formed therein. A pair of axle shafts used to drive the vehicle engage respective bevel gears, which are also engaged to a pair of planet gears in the differential. The planet gears are rotatably mounted in the ring gear opening and may be mounted on a shaft. The differential includes a block having at least a first end and a second end which engage the ring gear opening, and the block has a longitudinal axis which is not coincident with the axis of rotation of the planet gear. The block thus increases the strength of the ring gear and allows use of a ring gear having a larger opening.

Abstract: A hydrostatic transmission design incorporating a filter housing mounted adjacent to check valves in a center section. The filter housing can be secured to the center section by the check valves, which also may include high pressure bleeds to allow hydraulic fluid to flow from the hydraulic circuit. A shield may be located between the high pressure bleeds and the filter to prevent damage by the fluid to the filter as it exits the bleeds. The filter housing can also include integral projections on which a bypass actuation member can be mounted.