Abstract: A method of securing a metallic gear on a metallic shaft provides an improved axial retention of the gear on the shaft in particularly severe applications, as encountered in gear pumps. The method involves plastic deformation of the annular interface regions defined at the external junctions of a gear and shaft by the application of compressive forces over same, after the gear has been secured onto the shaft by conventional methods. The preferred practice of the method first includes the steps of radially retaining the gear on the shaft via shrink fit procedures which include heating the gear, cooling the shaft, inserting the shaft into the bore of the gear, and allowing the temperatures of the gear and shaft to equalize.

Abstract: Hydraulic equipment useful as a pump or motor intended for applications where hydraulic fluid is exposed to contamination by abrasive particulate material is disclosed. Leakage paths from the high pressure chamber in a gear pump or motor are provided with inserts of an abrasion and erosion resistant material at points where wear from abrasives in the hydraulic fluid is aggravated. In particular, the bearing surfaces of the pressure loaded side plates are provided with an insert of abrasion and erosion resistant material in the mesh region of the teeth. Erosion and abrasion resistant rings are located on the side plates in the region surrounding the openings for the shafts and extending interiorly of the tooth root circle to the journal bearings.Also disclosed are radial sealing shoes which are supported by the side plates and are radially urged into sealing relationship with the tips of the teeth by the pressure existing at the high pressure side of the gears.

Abstract: The disclosure relates to a control system for hydraulic pumps driven by the engine of a vehicle or the like and used for operating an auxiliary mechanism such as a vehicle mounted implement, a power steering system or the like. The disclosed system includes means for interrupting the flow of operating fluid to the pump during periods of time when the output of the pump is not required. With the pump inlet closed, all of the hydraulic fluid on the suction side is immediately pumped out the pump discharge, leaving only a small amount of residual oil on the surface of the working parts to provide lubrication. A valve is provided to prevent fluid from returning to the pump because of downstream pressure in the circuit. Control means, utilizing pressure downstream from the pump, for operating the valve in the inlet of the pump are disclosed.