GB848862A - Improvements relating to a hydraulic pressure system including a rotary device whichrequires lubrication - Google Patents

Abstract

848,862. Steering vehicles. GENERAL MOTORS CORPORATION. Aug. 27, 1958 [Sept. 23, 1957 (2)], No. 27468/58. Class 79(5). [Also in Groups XXVIII, XXIX, XXXII and XXXIV] In a power steering system for a motor vehicle, a pump 105 is arranged to circulate liquid from a main reservoir 106 through a conduit 108<SP>1</SP> to a flow control and by-pass valve 107 and return the liquid via a conduit 119 to the reservoir 106, part of the return flow being directed to an auxiliary reservoir 168, located within the reservoir 106 and having an overflow connection therewith, from which it is supplied by a pump 180<SP>11</SP> to lubricate an air compressor 100 and is returned to the auxiliary reservoir by another pump 180<SP>1</SP>. The air compressor 100 (see Group XXVIII) forms part of the motor vehicle air spring suspension system (see Group XXXII) and it is driven from the engine 120 by means of a belt 122 and pulleys 121, 123. A rear extension of the compressor crankshaft drives the power steering pump 105, the reservoir 106 of which is mounted on top of the pump 105. The lubricant pumps 180<SP>1</SP> 180<SP>11</SP> have a common pumping element comprising a two lobe rotor and all three pumps are driven from the compressor crankshaft. A relief valve 200 is arranged in the passage 196 to limit the pressure of lubricant supplied to the compressor lubrication system. A filter element 173 and restrictive passage 171 are disposed in the return line 176 to the auxiliary reservoir 168. The steering unit comprises a steering wheel 115, a steering shaft 114 carrying a nut 129 engaging a rack segment 131 mounted on a shaft 132 connected to a rocker shaft which actuates the steerable front wheels of the vehicle, and a rack segment 133 mounted on the shaft 132 and engaging a rack 134 actuated by a servomotor 112 which is controlled by a valve 110. Normally, when steering is not required, liquid circulates from the pump 105 through the line 108 into a chamber 142 and then through passages 145, 146 into return lines 154 and 119 and back to the reservoir 106. When steering is required, rotation of the shaft 114 effects axial movement of the spool 150 whereby liquid is supplied to the appropriate side of the piston 135 of the servomotor 112.