GB610068A - Improvements in or relating to rotary hydraulic power devices - Google Patents

Abstract

610,068. Hydraulic clutches. REYNOLDS METALS CO. Dec. 11, 1945, No. 33437. Convention date, April 27. [Class 69 (ii)] [Also in Group XXVI] A multi-cylinder hydraulic pump comprises parallel annular cylinders 11 ... 11xxx containing rotors, on a shaft 12, each with a radial, tooth-like piston, the pistons coacting with recesses 3a, in a common abutment 3, and a delivery-pressure controlled valve 41 which may cut out delivery ports 42, 42x, &c. as a piston 25 is moved to the right under increasing delivery pressure. The abutment shaft is coupled to the shaft 12 by gears 15, 15x. An inlet manifold supplies the cylinders 11 ... 11xxx and each cylinder has a delivery port 42 &c. leading to a cylinder 43 connected with an outlet 45, or a byepass 44, leading back to the fluid supply. Under low back-pressure from the outlet 45, which may lead to a hydraulic tool or engine, the piston 41 is pressed to the left of the cylinder 43, as shown, by a spring 28, and all fluid delivered from the cylinders 11 ... 11xxx through ports 42 &c. passes into the cylinder 43 and through the byepass 44. As the speed of shaft 12 is increased, the pressure in the cylinder 43 rises, fluid being forced through holes 26a in a wall 26, and the piston 25 is forced to the right causing the piston 41 to cut out the byepass 44, and, later, outlets 42, 42x, &c. until only the cylinder 11xxx is delivering fluid to the outlet 45. With decrease in load and resulting decrease in pressure in cylinders 43, the spring 28 gradually forces the piston 41 to the left resulting in the circulation of a larger volume of fluid at a lower pressure. A bleeder hole 29 acts as a drain for leakage fluid. The piston 41 carries a pressure-relief valve. Fig. 5 shows a motor in which the piston 41 has a rod 52 pressed on by a spring 54 under control of a hand wheel 56 provided with a lock-nut 57. Fluid under pressure enters through a port 60 leading to the cylinder 43 and passes through one or more ducts 42, 42x, &c. according to the position of the piston 41, the fluid being exhausted into a manifold 51 which is connected to cylinder 43 and outlet 59. A stop 61 is provided to prevent the piston 41 from closing off the first cylinder 11. As the load on the shaft 12 lightens, the pressure in the cylinder 43 to the left of the piston 41 decreases, allowing one or more inlets 42xx to be cut off. On increase in load on the shaft 12, more of the cylinders 11 &c. are brought into operation, thus increasing the torque on the shaft 12, but decreasing its speed. In a further arrangement, Fig. 6, a six-cylinder pump has three passages 75, 76, 77 connecting pairs of cylinders, so that fluid enters, say, a cylinder 66x and passes through a passage 75 into the cylinder 67x before being exhausted. The shaft 70 is driven by an external engine.