Parker-hannifin Corporation

Frank P Holzschuh

Xingen Dong

Barun Acharya

Allen Burdette

Albert C Ellenburg

A compact, integrated hydrostatic transmission without reduction gearing wherein the pump and motor are contained within a single housing, and an output shaft extends from the housing inline with a shaft of the motor. The output shaft is directly connectable to a wheel of a vehicle. The pump and motor share a common sump within the housing in which pump and/or motor leakage is collected.

Hydrostatic transmission

Improvement in a combination valve including check valve and pressure relief valve portions for regulating fluid flow pressure and direction in a hydraulic circuit, wherein a valve seat includes, in addition to a central aperture, a plurality of peripherally-spaced axial cross-port orifice holes, of same or differing diameter and a plurality of intersecting, circumferentially-spaced, radial, semicircular holes; a spring cap including four adjoining axial portions of differing outer diameters, with a first portion being a protrusion that locates an end of a relief valve compression spring, a second portion having flat outer tool locating surfaces used for rotating the spring cap for axial adjustment relative to a valve stem, a third portion having a reduced radial wall thickness for easy crimping thereof relative to a valve stem, and a fourth portion having a coaxial recess for centering and physically retaining one end portion of a check valve compression spring.

Combination valve

A speed adjusting mechanism that includes a return to neutral feature for returning a control member of a pump to neutral after the control member has been moved to a forward or reverse position. The speed adjusting mechanism is characterized by the use of a torsion spring that enables the mechanism to be composed of just a few parts.

Growing community of inventors

Greeneville, TN, United States of America

Frank P Holzschuh