GB1323794A - Clutch control thrust bearing - Google Patents

Abstract

1323794 Clutch control SOC ANON FRANCAISE DU FERODO 19 April 1971 [31 March 1970] 25794/71 Heading F2L In a clutch control mechanism for a motor vehicle wherein an axially slidable control sleeve 21 operates a valve 50 controlling the supply and exhaust of pressure fluid to a servo 30 having a piston 24 which acts through a clutch release thrust bearing 38 and a sleeve 39 on the inner ends of spring fingers 19 of a diaphragm spring 15, axial reaction forces on the driving shaft are reduced by arranging the cylinder 25 of the servo to react on the clutch cover 13. The cylinder 25 acts through a thrust bearing 31 on a sleeve 32 fast with the clutch cover 13. A spring 52 biases the valve element 50 to the position shown in which it closes a compressed air inlet port 53 and a spring 60 biases the sleeve 21 and piston 24 apart to open an exhaust port 56. The exhaust port 55 is closed on initial axial movement of the sleeve 21 against the bias of the spring 60 and thereafter further axial movement of the sleeve 21 opens the inlet port 53 to supply compressed air to the servo chamber 30. The pressure in the chamber 30 moves the piston 24 left to follow the movement of the sleeve 21 and disengage the clutch. The effective area of the cylinder 25 is at most equal to the effective area of the piston 24 and preferably less than the effective area of the piston 24 to provide a feedback "feel" pressure through the control sleeve 21 to the clutch pedal. An initial clearance G 1 is provided in the clutch engaged position between the cylinder 25 and a valve housing 36 of the sleeve 21 to allow for clutch lining wear. Pins 65 prevent relative rotation between the sleeve 21, piston 24 and cylinder 25. A spring (62), Fig. 5 (not shown), may be provided between the piston 24 and cylinder 25 to ensure that the sleeve 39 remains in contact with the spring fingers 19 during clutch engagement. The pressure fluid may alternatively be suction or liquid pressure. In the event of failure of the fluid pressure supply, the sleeve 21 can act directly on the piston 24 to effect clutch disengagement. In Fig. 6 (not shown) a radial clearance is provided between the inner race of the bearing (38) and the piston (24) to permit the sleeve (39) to float radially and centre itself relative to the diaphragm spring. In Fig. 7 (not shown) the sleeve (21) slides on an extension (71) of the piston (24).