Deere + Company

James Henry Kress

Richard A Michael

Billie Gene Hunck

A hydrostatic transaxle assembly having first and second output shafts extending outward therefrom. The assembly includes a housing enclosing a portion of the first and second output shafts and forming a generally cylindrical chamber therein. A manifold is positioned around one of the output shafts and has an outer surface which mates with an inner surface of the housing. A pair of high torque, low speed motors are secured to an inner surface of the housing on opposite sides of the manifold. One of the motors is splined to the first shaft while the other motor is splined to the second shaft. Operation of the motors cause the respective shafts to rotate. The motors operate on pressurized fluid which is supplied through fluid passages. A control valve is positioned across the fluid passages to regulate the operation thereof. The assembly further includes means for axially retaining and hydraulically balancing the motors against the sides of the manifold such that hydraulic forces acting on one of the motors will be transferred to and offset by a similar force acting on an opposite surface of the second motor.

Hydrostatic transaxle assembly

A planetary transmission for selectively shifting among four forward speeds includes a first ring gear secured to a drive shaft. The first ring gear drives a compound planetary gear set which is journaled on a driven-shaft-connected planet carrier. A first planet gear set of the compound planetary gear set meshes with a carrier-journaled, third planet gear set which meshes in turn with a second ring gear. The first planet gear set further meshes with a first sun gear which is concentric with the first ring gear and which encircles and is clutchable to the driven shaft to provide one forward speed ratio between drive and driven shafts. A second plane gear set of the compound planetary gear set meshes with a second sun gear which is coaxial with the first sun gear and concentric with the second ring gear. First, second, and third brakes are respectively connected to the second ring gear, the second sun gear, and the first sun gear to stop and allow rotation of said gears to provide three additional forward speeds.

Transmission

A planetary transmission for selectively shifting among three forward and one reverse speeds includes first and second sun gears respectively secured to and clutchable to a drive shaft to provide a first forward speed. A planet carrier, secured to a driven shaft, surrounds the sun gears and carries a first planet gear meshing with the first sun gear and a compound planet gear comprising a second planet gear meshing with the first planet gear and a third planet gear meshing with the second sun gear. Respectively concentric with the first and second sun gears are brake-associated first and second ring gears which respectively mesh with the first and third planet gears. First, second, and third brakes are respectively connected to the first ring gear, the second ring gear, and the first sun gear to stop and allow rotation of said gears to provide two forward and one reverse speeds; a third forward speed is provided by clutching the second sun gear to the drive shaft.

An auxiliary hydrostatic drive system for a vehicle includes a pump, a reservoir, fluid motors connected to the normally non-driven steerable wheels of the vehicle, reciprocating piston-type wheel drive motors connected to the normally nondriven steerable wheels, fluid lines interconnecting the pump and reservoir with the inlet and outlet ports of the wheel motors, and a motor control valve movable to either side of a neutral fluid blocking position to forward and reverse drive positions. An additional valve interconnects the motor ports with the drive chambers of the motors whenever the motor control valve is in the neutral position so that during periods when the motors are not connected to the pump and are driven mechanically, they function as pumps to pressurize their drive chambers and hold their pistons off the drive cams.

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Cedar Falls, IA, United States of America

James Henry Kress