Patent GB-921570-A (GB)
Title: Improvements in and relating to hydrodynamic couplings
IPC: F16D33/06
Filed: 1962-01-15
Abstract: 921,570. Hydraulic transmission of power. C. SCHULER-VOITH, M. VOITH, H. W. SCHWEPPENHAUSEN, and C. KNAPP, [trading as VOITH-GETRIEBE K.G.]. Jan. 15, 1962 [Jan. 14, 1961], No. 1474/62. Class 69 (2). [Also in Group XXXI] An hydrodynamic coupling having a freewheel action comprises a pump wheel 2, Fig. 1, and turbine wheel 3 enclosing an annular working chamber which communicates with a receiving container 8 by way of at least one inlet duet 12 for filling the working chamber and at least one outlet duct 13 for emptying the working chamber, the outlet duct being disposed in the radially inner region of the working chamber and facing in such a direction that liquid is discharged automatically from the working chamber under the action of a circulating flow directed radially inwards of the pump wheel. The pump wheel may be driven by the shaft 5 of an engine 1 and the turbine wheel drive the propeller 4 of a ship. The shaft 5 also drives a pump 9 by which fluid from the container 8 is passed through a pipe 10 to the inlet duct 12 under the control of a manually-operated valve 11. During normal running when the speed of the pump wheel exceeds that of the turbine wheel, the flow of liquid in the working chamber is in the direction of the arrows 14. If the speed of the engine lags and the speed of the turbine wheel exceeds that of the pump wheel, the direction of flow in the working chamber is reversed and the radially inwardly moving liquid in the pump wheel then passes through the outlet ducts 13 to empty the coupling. In another embodiment, the outlet ducts are formed in the radially inner portion 2a of the pump wheel. Liquid from the inlet ducts 12 is passed directly to the pump wheel by a wall 17. In a further embodiment, the outlet ducts 30, Fig. 3, are formed in the pump wheel 31 and pressure at the openings of the ducts is increased by a baffle 32 to increase the flow from the coupling when the flow is radially inwards of the pump wheel. The cross-section of the outlet ducts can be varied by an axially-displaceable slide-valve 33. In another embodiment, the outlet ducts 42, Fig. 4, are arranged as in Fig. 1 and the receiver container 44 is carried by the pump wheel 40. A spring-pressed ball valve 47 maintains the inlet ducts 45 from the receiver container closed during low speeds of the pump wheel but opens the ducts under the action of centrifugal force as the speed of the pump wheel increases. Two couplings 59, 60, Fig. 5, as described, together with a torque converter 56 and gearing 52, 55, 57, 61 may be incorporated in the drive from a gas turbine 50 to the axles 54, 54a of a locomotive, the couplings automatically emptying to provide a freewheel action in the event of a breakdown of the gas turbine when driving the locomotive. In another application, a plurality of propulsion units are each connected by separate couplings to a common output shaft driving the propeller of a water craft so that, in the event of one of the units failing, the freewheel action of the associated coupling prevents drive from the remaining units being transmitted to the damaged unit.