| 摘要 |
837,775. Swash plate pumps. INTEGRAL Ltd. May 29, 1958 [June 18, 1957], No. 19171/57. Class 102(1). [Also in Group XXIX] The speed of a hydraulic motor driven by the liquid delivered by a multiple plunger pump which may be connected e.g. to an aircraft engine for driving an alternator coupled to the hydraulic motor, is maintained constant by means comprising spill valve sleeves associated with the pump plungers and movable to vary the effective delivery strokes of the plungers by a servo piston which is exposed on its opposite sides to the delivery pressure of the pump and to the pressure in an outlet conduit from the pump delivery line controlled by a leakoff valve, this leak-off valve being responsive to a variable hydraulic signal pressure representative of the speed of the hydraulic motor. The hydraulic motor 2 coupled to the alternator 3 is driven by the liquid delivered by a swashplate pump 1 having hollow plungers 9, 10 which receive liquid through inlet ports in the pump cylinders 90 at the end of their suction strokes. Spill ports 12 in the plungers, through which liquid is spilled during a variable part of each delivery stroke, are controlled by movable valve sleeves 24 connected through a spring loaded plate 15 to a servo piston 18. This piston is subject on one side to the pump delivery pressure through passage 118 and on the other side to the pressure of controlled liquid supplied to a conduit 19 through a restriction 20. An open end of conduit 19 is obturated by a hinged half ball leak-off valve 8 which is subject in one direction to the force of a loading spring 28 plus a datum pressure from an outlet 6 of the hydraulic motor and in the opposite direction to'the pressure in a signal conduit 5 connected to the peripheral discharge chamber of an impeller 4 which takes its suction from the motor outlet 6. The half ball valve is biased towards the closed position by a differential area piston 23 subject on opposite sides to the pump delivery pressure through a pipe 27 or alternatively to the pressure from conduit 19. On a rise of motor speed above that determined by loading spring 28, the pressure in conduit 19 is reduced and servo piston 18 causes the sleeves 24 to move to the right, thus reducing the effective delivery stroke of each plunger to restore the predetermined speed. Conversely on falling speed, the pump delivery is increased. Specification 820,417 is referred to. |
