Caterpillar Inc.

Howard Savage

William K Engel

David P Smith

Michael H Hinrichsen

Kenneth R Watts

Donald H Sherman

Phillip J Wenger

Guy C Carlson, Jr

A method is provided for producing a piston assembly adapted for use in a hydraulic pump or motor and having an overall length shorter than previously known piston assemblies while maintaining a strong mechanical connection and a high, efficient volumetric output. The method includes the steps of forming a slipper with a spherical ball on one end; forming a piston having a body portion and a connecting portion, the connecting portion having a spherical bottom surface, a groove spaced from the bottom surface and a contoured portion having an angled outer surface and an inner surface; inserting the spherical ball into the cavity; forcing the contoured portion inwardly to place the inner surface into contact with the spherical ball and to substantially longitudinally align the outer surface of the piston body with the angled surface of the contoured portion; heat treating the piston to a predetermined hardness and depth; and finishing the total longitudinal length of the piston to a finished size.

Method of producing a piston assembly

Hydraulic piston pumps and motors are used in various applications to power implements, steering, propel, and auxiliary systems. However, it is important to keep the piston weight and compressible fluid volume low in order to have a smaller more efficient pump. The subject piston is manufactured in a simple manner to achieve a reliable, light weight design. The piston has a cylindrical body having an outer surface. The piston is manufactured by forming a first bore having a large diameter in the body extending from the outer surface and terminating at an annular shoulder. A second bore is formed which extends from the annular shoulder to a predetermined depth. A tube is inserted through the bore and extends a predetermined distance into the second bore. A cap has a bore and is positioned on the body in abutment with at least a portion of the outer surface. The cap slidably receives the tube through the bore. The cap is brazed to the body and the tube is brazed to the cap and to the body to form an isolated annular cavity in the piston.

Method of manufacturing a piston for an axial piston fluid translating

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Joliet, IL, United States of America

Howard Savage