GB828158A - Improvements relating to hydraulic turbo couplings - Google Patents

Abstract

828,158. Hydrokinetic couplings. SINCLAIR, H. June 19, 1957 [July 2, 1956], No. 20453/56. Class 69 (2). An hydraulic turbo coupling having hydraulically controlled quick-emptying valves 6 is provided with means for reducing the time lag in the opening of the valves when the coupling is operating at low speed. Each valve comprises a disc 16 which seats to close communication between an orifice 8 open to the working chamber of the coupling and an outlet port 28, being urged to the seating position by pressure in a space 32 which is provided with a leak-off nozzle 19 and centrifugally controlled nozzles 21. During operation of the coupling liquid continually drains from the working chamber through restricted ports 30 in the valves 6. An adjustable scoop tube 34 supplies liquid from a rotating reservoir 33 to the working chamber via a cooler and also supplies liquid through a feed tube 41 to the valve space 32. In the operation of the coupling at full speed, when the scoop tube is withdrawn to cut off the supply of liquid, the space 32 drains through the leak-off nozzle 19 until the liquid in the working chamber is able to unseat the disc and obtain substantially unrestricted communication with the reservoir 33. At, say, three quarters of the full coupling speed, one of the centrifugally controlled nozzles 21 is arranged to open so that liquid can exhaust through this nozzle and nozzle 19. This counteracts the effect of the reduced centrifugal force of the liquid in tube 41 and gives the same time lag in the unseating of the disc as at full speed. At, say, half speed the other nozzle 21 is arranged to open. A greater number of nozzles 21 opening at different speeds can be employed to equalize the time lag at a greater number of speeds. Each feed tube 41 may supply a plurality of valves 6, or a feed tube may be associated with each valve and the spaces 32 of a group of valves be interconnected so that one group of control nozzles 21 controls the group. Instead of using nozzles 21 that are either fully open or fully closed the nozzles may open progressively. In addition a centrifugal control nozzle may be thermostatically regulated to decrease the leakoff area with increased temperature of the working liquid.