GB962361A - Hydrostatic drives - Google Patents

Abstract

962,361. Driving gear of I.C. engine. DOWTY TECHNICAL DEVELOPMENTS Ltd. June 12, 1963 [May 21,1962], No. 19441/62. Heading F1B. [Also in Division F2] A primary power unit and at least the hydraulic pump of a hydrostatic drive on a vehicle are combined to form a single unit having an overall length not greater than the length of the primary power unit. As shown, the crank-shaft 3 of a fourcylinder in-line internal combustion engine 1 drives through gears 15, 24, 23, the input shaft 21 of a hydrostatic transmission comprising a pump 16 and motor 17, both of the tilting yoke head infinitely variable displacement type, arranged, in an engine casing 9, parallel to and the same length as the crank-shaft 3. Rotation of the pump shaft 21 displaces liquid between the pump and motor, through links 48, 49, to drive the motor output shaft 29, the speed ratio of the transmission being controlled by the relative tilt angles of the pump and motor yokes 33 which are inter-connected by the pivotal links 48, 49, and operated by a servo motor 52 connected through an arm 55 to the pump yoke and adjusted through a control rod and spindle 56, 57. Make-up fluid is supplied to the transmission unit by a gear-pump (Fig. 3 not shown) using the engine lubricating oil, the pump also supplying pressure liquid to the servomotor 52 and other hydraulic apparatus external to the engine. The casing of the combined primary power unit and hydrostatic drive may further accommodate a differential gear driven by the hydraulic motor, with a pair of shafts extending from the combined unit, one to each driving wheel of the vehicle. Alternatively, in an arrangement having only the hydraulic pump of the transmission combined with the primary power unit as a single member, the pump output liquid pressure may be piped to a motor located in any required position for the output drive.