GB542737A - Improvements in or relating to hydraulic clutches or couplings - Google Patents

Abstract

542,737. Hydraulic clutches. HYLAND, C. Sept. 23, 1940, No. 14449. [Class 69 (ii)] In a hydraulic coupling or clutch comprising a radial cylinder pump having its cylinder block 1 carried by a driving shaft 2 and its pistons 13, 14 operated or controlled by an eccentric 15 carried by a rotary pump casing 3 associated with a driven shaft, the pump is initially loaded by spring-loaded cylinder outlet valves 21, which on excessive loading or resistance, open to allow the excess pressure oil to be delivered into a conduit or duct 20 common to all the cylinder inlet valves and from which such oil can be drawn into the cylinders during the return stroke of their pistons. The pump cylinders are either main, 11, or auxiliary, 12, and their pistons 13, 14 are actuated by the eccentric 15. A valve chamber 19 is associated with each pump cylinder, those for the main cylinders having pressure release valves 21 arranged co-axially with lightly loaded inlet valves 22 leading from the conduit 20 and the chambers for the auxiliary cylinders, outlet and inlet valves 23, 24. Normally the whole clutch rotates solidly but if excessive torque creates excessive pressure in a main cylinder 11, its valve 21 opens and pressure oil is delivered to the conduit 20 to enter the other cylinders through their inlet valves. As long as this continues, the clutch slips and the auxiliary pistons pump oil from a sump 7 to the conduit 20, slightly increasing the pressure therein, excluding air therefrom and promoting circulation of the oil to dissipate the heat generated. The valve chambers connect with the sump 7 through a sliding valve member 29 in the driving shaft 2 and when the valve member 29 is moved manually to its extreme end position, an annular port in the member puts all the main cylinders into communication with each other to render the clutch inoperative.