GB817021A - Torque transmitting fluid coupling - Google Patents

Abstract

817,021. Cooling engines. SCHWITZER CORPORATION. April 12, 1957 [June 4, 1956], No. 12001/57. Class 7(2) [Also in Group XXIX] A hydraulic coupling for driving the radiator cooling fan 30 of an internal combustion engine comprises a disc 32 splined to an input shaft 29, and a housing 26, 27 forming the output member of the coupling and including a partition 35 which separates a reservoir 33 from a working chamber 31. The housing is driven by the viscosity of a film of liquid between the disc and the adjacent walls of the working chamber. An annular reservoir 34 is provided in the part 26. The partition 35 is provided with inlet ports 37 controlled by a valve plate 38 which is biased by a spring 41 to close the ports and is opened by a shift pin. 47 controlled by an. element 50 responsive to the temperature of the engine coolant. The partition has restricted outlet ports 36 adjacent its periphery. On starting, and with the engine coolant cold, the inlet ports 37 are closed, and liquid in reservoir 34 and chamber 31 is discharged through the ports 36 to the reservoir 33. The housing and fan remains substantially stationary. When the engine heats up the element 50 displaces the valve plate and so opens the inlet ports 37, and liquid enters the chamber 31. A film of liquid is built up between the adjacent faces of the disc 32 and the walls of the chamber and the housing is rotated. The periphery of the disc is notched to form vanes 44, and the walls of the chamber formed with guide ring 45, 46, to direct the liquid between the vanes. This facilitates a cooling circulation of fluid through the ports 36, reservoir 33 and ports 37 back to the working chamber. The disc may be provided with cork facings to prevent metal to metal contact. The input shaft 29 has fast therewith a coolant pump rotor 13 and a pulley 23 belt-driven from the engine crankshaft. The disc 32 may be the output coupling member and the housing 26, 27 the input coupling member.