Caterpillar Inc.

Guy C Carlson, Jr

William K Engel

David P Smith

Robert J Huebner

Donald H Sherman

Howard Savage

Phillip J Wenger

Axial piston fluid translating units commonly experience undesirable shaft deflections and barrel tilting during operation. A fluid translating unit includes a barrel plate interposed the end of a barrel and a porting surface defined within a housing thereof. The barrel plate is axially spaced from an end of the barrel and is in face sealing engagement with the porting surface. The barrel plate defines a plurality of fluid ports, each communicating between one of a plurality of barrel cylinder bores and the porting surface. In one aspect a plurality of counterbores are provided in the barrel in surrounding relation to the fluid ports. A plurality of seal rings having a sealing end defining an annular seal face of a predetermined width for face sealing engagement with the barrel plate. The seal rings are each disposed in one of the counterbores in circumferential sealing relation of a predetermined length which is no greater than the width of the sealing face. A plurality of annular springs are disposed in the counterbores for urging the seal rings into sealing engagement with the other of the barrel and the barrel plate. This arrangement permits tilting of the barrel without damaging contact or excessive leakage between the barrel plate and the porting surface.

Axial piston fluid translating unit with sealed barrel plate

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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Minooka, IL, United States of America

Guy C Carlson, Jr