Patent GB-919442-A (GB)
Title: Improvements relating to power transmission arrangements incorporating hydraulic turbo couplings
Inventor: CLEMENTS HERBERT ARTHUR
IPC: F16D33/06
Filed: 1960-12-21
Abstract: 919,442. Hydraulic transmission of power. FLUID-DRIVE-GEARS Ltd. Dec. 15, 1961 [Dec. 21, 1960], No. 43995/60. Class 69 (2). A power transmission comprises two hydraulic couplings L, H having their impellers L1, H1 drivably connected to each other and to an input shaft 16 and their runners L2, H2 drivably connected respectively to two output shafts L15, H15, each coupling having an adjustable scoop tube L10, H10 with its orifice L11, H11 in a scoop chamber L7, H7 in free communication with the associated working chamber, the scoop tubes being interconnected by a transfer duct 13 whereby the working circuits of the couplings can be selectively filled and emptied by appropriate control of the scoop tubes, and additional control means to increase or decrease the total quantity of liquid in the system comprising the scoop chambers, scoop tubes and transfer duct. The couplings may be associated with forward and reverse gearing or, as described, with low and high speed shafts L15, H15. The scoop tubes are adjustable by servomotors L14, H14 supplied with compressed air under the control of valves 34, 50 in turn controlled by a hand-operated valve 30 and a compressed air-operated valve 45. A further valve 61 operated by movement of the valves 34, 50 controls a supply of compressed air to a bag 19 in a reservoir 18 connected to the transfer duct 13, inflation of the bag displacing liquid from the reservoir into the duct. In the position shown, the scoop tubes are fully extended so that both couplings are empty, the pressure in the transfer duct is maintained at a low level by a relief valve 39 urged to a closed position by a weak spring 42, and the bag 19 is deflated so that the reservoir is full, a pump 70 maintaining a flow of liquid through the sytem to compensate for leakage losses. When the valve 30 is moved to its alternative position, a compressed air supply P is connected to a line 32 and actuates valve 33 to connect a compressed air supply R to the upper end of the servomotor L14 whereby its scoop tube L10 is retracted to permit filling of the low speed coupling L1. At the same time, the pressure in line 32 acts to reinforce the spring 42 of the relief valve 39 so that the latter will only open under high pressure. The downward movement of the piston L21 of the servomotor L14 displaces air through a line 37 and the valve 34, which is now in its alternative position, to a line 66 to cause the valve 61 to move to its alternative position and permit a compressed air supply Q to inflate the bag 19 and displace liquid in the reservoir into the duct 13 and coupling L1 which is thus rapidly filled. When the reservoir is empty, the pressure in line 66 gradually drops as a result of a throttled connection 68 to atmosphere to enable the valve 61 to return to its initial position and liquid from pump 70 pass through the scoop chamber L7, scoop tube L10 and duct 13 to the reservoir. The change from the low speed coupling L to the high speed coupling H is effected by an air supply A moving valve 45 to its alternative position wherein a line 49 is connected to the line 32 and moves the valve 50 to its alternative position, the movement of the valve connecting a compressed air supply S to a line 53 leading to the upper end of the servomotor H14 and a chamber 35 to return the valve 34 to its initial position whereby the upper end of the servomotor L14 is connected to exhaust and the lower end to the supply R to extend the scoop tube L10 and empty coupling L. The supply to the upper end of servomotor H14 retracts the scoop tube H10 to permit coupling H to be filled, the air displaced beneath the piston H21 passing through valve 50 to line 66 to actuate valve 61 and connect supply Q to the bag which is again inflated to displace liquid from the reservoir into the duct to rapidly fill the coupling H. The throttle 68 thereafter again allows the pressure in line 66 to drop and the valve 61 return to its initial position so that liquid from the pump 20 can fill the reservoir.