GB539946A - Improvements in or relating to couplings for the transmission of power - Google Patents

Abstract

539,946. Hydromechanical variable-speed gear. SULZER FRERES SOC. ANON. March 29, 1940, No. 5665. Convention date, May 17, 1939. [Class 80 (ii)] [Also in Group XXIX] A coupling for transmitting power from a reciprocating engine to a turbine or supercharging blower comprises intermeshing toothed wheels mounted in a casing having passages communicating with an accumulator, the wheels acting as a pump to raise the pressure in the accumulator, or as a motor driven by the accumulator according as to whether the speed of the engine is increasing or decreasing. In the apparatus shown in Figs. 2 and 3, the coupling comprises a sun-wheel 11, and planet-wheels 10 mounted in a casing or carrier 12 which is connected by a disc 17 to the engine crank-shaft 3. An output shaft 18 is connected to the casing. The sun-wheel is connected to a pinion 6 which drives the blower through speed-increasing gearing. Passages 13, 21, and 14, 24 in the casing 12 communicate through pipes 26, 27 with accumulators 15, 16 which are supplied with air and oil by means of a compressor 32 and a pump 30 in communication with pipes 31 and the pipes 26, 27 respectively. Relief-valves 36, 37 permit excess oil to flow through dip-pipes 38, 39 pipes 40, 41, and the pipes 27, 26 from one accumulator to the other. When the shaft 3 is started, the wheels 10, 11 pump oil from the passages 13 into the passages 14, 24, and the pressure in the accumulator 16 rises relatively to that in the accumulator 15. The pumping action retards the wheels 10, the wheel 11 commences to rotate, and ultimately the wheels 10 are prevented from rotating, and the wheel 11 is driven at the same speed as the shaft. If the speed of the shaft increases, the wheels again act as a pump, the pressure in the accumulator 16 is increased, and the wheel 11 is accelerated slowly. If the speed of the shaft decreases, the wheels 10, 11 commence to act as a motor driven by the accumulator 16, and the speed of the wheel 11 is prevented from falling quickly. If the blower is obstructed, oil is delivered through the relief-valve 35 into the accumulator 15, and the coupling slips. To stop the blower, the passages 13, 14 are short-circuited by means of a multi-way cock 45 in the pipes 26, 27. Instead of air-cushions for the oil in the accumulators, spring or weight-loaded pistons may be employed. When a reversible engine is employed, the crankshaft is connected to a toothed annulus 50, Fig. 5, engaging the wheels 10, and the output shaft 18 is provided with a toothed wheel 51 co-operating as a pump or motor with a toothed wheel 52, the casing 53 of the toothed wheels having passages 54, 55 which communicate through pipes 56, 57 with the pipes 26, 27 leading to the accumulators 15, 16. A cock 58 in the pipes 56, 57 is connected by linkage 59, 60, 61 to the above-mentioned cock 45. During forward or reverse running, the cocks are set to connect the passages 13, 14 in the casing 12 to the accumulators, and to short-circuit the passages 54, 55, or vice versa. During forward running, the wheels 50, 10, 11 act as a speed-regulating pump or motor in the above-described manner. During reverse running, the wheels 51, 52 act as a speed-regulating pump or motor by stopping or accelerating the shaft 18 and casing 12. The toothed wheel is turned in the same direction during forward or reverse running.