Patent GB-1105544-A (GB)
Title: Hydraulic turbo coupling
IPC: F16D33/08
Filed: 1965-04-05
Abstract: 1,105,544 Hydraulic transmissions. ECLIPSE CONSULTANTS Ltd. 5 April, 1965 [6 April 1964], No. 14286/65. Headings F2C and F2D. In a fluid coupling, the volume of liquid in the toroidal working chamber defined by an engine-driven radially vaned impeller 10 and a radially vaned turbine 13 is varied by means responsive to impeller speed to maintain the power transmitting capacity of the coupling analogous to the power output of the engine. As shown, a reservoir 17 is rigid with the impeller and is divided by baffles 23, 24 and a partition 22 into compartments 25, 26, 27, 28. A shroud 19 rigid with the reservoir and provided with peripheral holes 21 extends closely around the turbine. Liquid is transferred from the compartment 28 to the compartment 25 by a fixed scoop tube 29 and from the compartment 27 to the working chamber, via an inlet 36, by a fixed scoop tube 33. The maximum capacities of the compartments 25, 26 are defined by the bore edges 41, 42 of, or, as shown, spill holes 43, 44 in the baffles 23, 24. Sets of valves 37, 38 respectively arranged in circular rows in the baffles 23, 24 are respectively closed above a predetermined impeller speed and below a predetermined impeller speed. The flow capacities of the valves and the tube 33 are all greater than that of the tube 29. With both sets of valves open during a lower speed range, liquid flows from the working chamber through the tube 29, the compartment 25, the valves 37, the compartment 26, the valves 38, the compartment 27, the tube 33, the inlet 36 and back to the working chamber, the compartments 25, 26 containing their minimum liquid quantities and the working chamber its maximum. On closure of the valves 37, during a higher speed range, the quantity of liquid retained in the compartment 25 is increased whereby the quantity of liquid in the working chamber, and the power transmission capacity of the coupling, are reduced. On closure of the valves 38, on impeller speed decrease occurring, as by a stalling load being applied to the turbine, the quantity of liquid retained in both compartments 25, 26 is increased whereby the quantity of liquid in the working circuit is so reduced that the coupling torque transmission capacity is substantially equal to the engine maximum output torque. The valves 37, 38 comprise port closure members 47, 48 at the ends of arms 49 (Figs. 4-6, not shown) provided with counterweights 50 and held by torsion bars 58. The arms 49, the torsion bars 58 and cylindrical port members 56 may be assembled as a unit. The port members 56, provided with loose fitting O-ring seals 60 to prevent leakage, are mounted with respect to the baffles 23, 24 so as to allow baffle deflection on liquid level change. In Fig. 7 (not shown), the mating faces of the closure members 47, 48 and the port members 56 are inclined for full engagement only at full closure; alternatively, the members 56 may be inclined. As shown, the valves 37 in the baffle 23 are provided in two rows having radially overlapping ports of the same size, the radially outer and inner rows of the valves respectively closing at lower and higher speeds to provide wide control ranges; alternatively these valves may be provided in a single row, may have different diameter ports, or may comprise single or multiple start spiral apertures. In an alternative arrangement, the compartments 25, 26 are arranged in parallel in the flow circuit.