Improvements in and relating to ship propulsion
598,654. Hydraulic power installations. BAXENDALE, B. F., PETTY, M. G. R.. and JONES, C. F. March 9, 1944, No. 4433. [Class 69 (ii)] [Also in Group XXXIII] A high-pressure hydraulic power installation comprises a number of Diesel engines 5 driving high-pressure piston-type pumps 6 connected by one or more mains 12a to one or more preferably reversible high-pressure piston-type motors 3, and means to control the speed, and preferably also the direction, of rotation of the shaft 24 of a ship's propeller driven by the motor, the fall power rating of any pump 6 being only a fractional part of the full power rating of any motor 3. The pumps and motors are preferably of the radial cylinder type, the number of engines 5 may equal, or be a multiple or sub-multiple of, the number of pumps 6, and the speed control means preferably acts on the engines 5. In the form shown, couplings 7 and reduction gears 8 are disposed between the engines 5 and pumps 6, the suction and delivery pipes 9, 12 of the pumps are provided with stop valves 10, 13, the motor 3 may be rotated in bearings 25 by hand gear 26 for inspection purposes as - described in Specification 598,666, and it is controlled by a pistonactuated valve 17. A shaft 21 carries cams 18, 19, 20 to actuate, respectively, a spring-controlled pilot valve 15, a spring-controlled distributing valve 16, and, through push-rods 23, the speed governors of the engines 5. With the control means in the stop condition, the high-pressure oil from the pumps is byepassed by valve 16 to the exhaust pipe 28. On initial turning of the cam-shaft 21, cam 18 moves pilot valve 15 which supplies oil to set the motor control valve 17 for direction of flow. On further turning of the cam-shaft, cam 19 moves distributing valve 16 which then supplies oil to the central inflow passage of the valve 17 and thence to the motor 3. On still further turning of the cam-shaft, cams 20 speed up the engines 5 without disturbing the settings of the valves, as described in Specification 598,668.