GB764416A - Hydraulic clutch - Google Patents

Abstract

764,416. Hydraulic clutches. WICKMAN, A. C. Jan. 14, 1955, No. 1171/55. Class 69 (2). An hydraulic clutch comprises a pump and a reservoir, flow through the pump being controlled by a valve responsive to a centrifugal governor. An hydraulic clutch comprises a geartype pump having planet gears 13 mounted in a driven casing and meshing with a sun-gear 14 on an output shaft 15. Partitions 11, 19 in the casing separate the pump from a reservoir, the partition 11 having inlet ports 18 and outlet ports 16, 17, and partition 19 having inlet and outlet ports corresponding to, but angularly offset from, those in the partition 11. A disc valve 23 controls communication between the ports. The volume of liquid in the reservoir is such that when the casing is rotated the centrifugally formed fluid ring covers the inlet ports and the outlet ports communicate with the central air space. The disc valve 23 has helically splined engagement with a sleeve 29, angular position of which is controlled by a centrifugal governor. At idling speeds the pump inlets are closed and the outlets partially open so that no drive occurs. At intermediate speeds throttled flow through the pump is permitted, and at greater speeds the inlet ports are partially open and the outlets closed so that the pump rotates solid. When used in a vehicle transmission the clutch may be disengaged to permit gear changing by moving the sleeve 29 axially to the right, thus rotating the valve 23 through the helical splines to a position in which the inlet ports are closed and the outlet ports are open. Sleeve 29 is prevented from axial movement during idling by a ring 35, having notches which are offset from teeth 36 on the sleeve under idling conditions.