Tecumseh Products Company

Kevin J Johnson

Richard T Ruebusch

Norman E Jolliff

Vance E Coble

Joseph V Miller

A hydrostatic transaxle assembly is drivingly connected to a power source and the power source is activated through an electric starter circuit. The hydrostatic transaxle includes an axial type hydrostatic transmission module having a pump which includes a plurality of axially arranged cylinders each including a piston therein. A tiltable swash plate includes a lateral surface rotatable within the hydrostatic transmission casing. The swash plate is in engagement with the plurality of pistons wherein tilting of the swash plate effectuates fluid displacement of the pump. A neutral switch is fixed relative to the transmission casing and includes a registering portion engaged with the swash plate to detect a neutral position and correspondingly allow starting of an electric starter through the starter circuit. A neutral adjustment assembly includes a control rod rotatably supported by the casing and a two piece shift lever is attached thereto. The two piece lever includes a first member attached to the control rod and a second member normally releasably fixed to the first member but selectively rotatable relative to the first member when loosened from the first member. A resilient biasing member has a first leg held substantially fixed to the casing and a second leg held substantially fixed to the second member of the shift lever to bias the first member of the shift lever into a neutral position and at least one fastener releasably fixes the first and second members together.

Neutral start switch and adjustment assembly for a hydrostatic transmission

A variable speed transmission including a rotatable input member, a fluid pump operatively engaged with the input member, a fluid in the pump being pumped in response to rotation of the input member, and a fluid motor in fluid communication with the fluid pump, fluid pumped by the pump being received by the fluid motor, the fluid motor being driven by fluid received by the fluid motor and having a variable output speed. Means are provided for selectively varying the displacement of the fluid pump or the fluid motor, whereby the output speed of the fluid motor is varied. A rotatable output member is operatively engaged with the fluid motor, and a reversible electric motor having an output shaft is provided, the output shaft having varying angular positions. The output shaft is in mechanical engagement with the displacement varying means, and the displacement of the one of the fluid pump and the fluid motor being varied in response to changes in the output shaft angular position.

Electric shifting of a variable speed transmission

A variable displacement hydraulic pump includes a pump cylinder barrel having a plurality of axially arranged cylinder chambers disposed therein and each cylinder chamber includes a reciprocating piston therein. The pump is rotatably supported by the pump block and a motor block is separable from and connected to the pump block. A hydraulic motor is rotatably supported by the motor block and hydraulically connected to the pump through a pair of continuous passages formed in the pump and motor blocks. The motor includes an axis of rotation substantially perpendicular to an axis of rotation of the pump. A motor includes a cylinder barrel having a plurality of axially arranged cylinder chambers disposed therein and each cylinder chamber has a reciprocating piston therein. A thrust bearing is supported by a portion of the pump and motor block and is receivably engaged with the pistons extended from the cylinder barrel of the motor. A stop member is attached to the portion of the pump and motor block and in contact with the thrust bearing wherein relative movement of the thrust member is restrained by the stop member.

Hydrostatic transmission having two-piece pump and motor block assembly

A fully integrated hydrostatic transaxle formed of three housing members, a hydrostatic transmission and axle housing member joined to a differential housing member along a vertical plane and joined to a hydrostatic transmission mounting plate and cover member along a horizontal plane. A hydrostatic transmission is connected to and suspended from the mounting plate and cover member. In a second embodiment, a hydrostatic transmission is mounted to a hydrostatic transmission and axle housing member, which in turn is fastened to a center housing member. The center housing member is in turn connected to an axle and differential housing member. The interfaces defined by where the housing members are joined together define substantially parallel vertical planes. Means for effectively unlocking the transmission and the differential is provided so that the operator can push the vehicle without encountering the resistance of back driving the hydrostatic transmission. A neutral position adjustment mechanism provides a tactile indication of the neutral position, and the mechanism can be readjusted to define the correct neutral position.

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Salem, IN, United States of America

Kevin J Johnson