GB844496A - Means for counteracting centrifugal force moments in rotary cylinder barrel engines - Google Patents

Abstract

844,496. Swash plate pumps. NEW YORK AIR BRAKE CO. March 18, 1958 [May 31, 1957], No. 8616/58. Class 102(1). [Also in Group XXIX] In a swash plate pump comprising a rotary cylinder block 23 abutting a valve plate 14 the tilting moment on the barrel 23 caused by the centrifugal forces acting on the pistons 31 is opposed by a balancing port located in the face of the valve plate 14. The plate 14 is bored at 49, 51 and the bores are fitted with tightly fitting plungers 54, 55. The plunger 55 is solid. In the plunger 54 are formed a balancing port 56 which communicates through bores 57, 58 with the discharge port in the valve plate and a surrounding annular groove 61 forming lands 62, 63 around the port 56, the land 63 being relieved by radial grooves 64. The areas of port 56 and land 62 in relation to the outlet pressure are so chosen that an average balance is achieved for given operating conditions. Where the outlet port and inlet port are interchangeable the balancing port 56 communicates with both ports through non-return valves. Where the pump or engine is reversible by tilting the swash plate through the neutral position each of the bores 49, 51 is fitted with a plunger similar to plunger 54. The barrel 23 is driven by a two part shaft 19, 21, the two parts being splined together at 22, the other end of the shaft 21 abutting the pump housing through a thrust plate 43. The barrel 23 is supported on the shaft 21 by engagement with a spherical surface 34 formed thereon, the centre of the surface lying on the axis of the shaft and in the plane containing the centres of spherical ends 32 formed on the pistons 31. The barrel 23 is driven by means of a torque tube 25 splined to the shaft 21 at 27 and to the barrel at 26 and is biased towards the valve plate 14 by a spring 28 one end of which engages the torque tube 25 and the other an adjustable ring 29 on the barrel. The angle of the swash plate 36 which is pivoted about the centre of the surface 34 is adjusted by means of the outlet fluid pressure which acts through a valve 48 on a piston 45 which is opposed by a spring loaded plunger 44. The inlet and outlet ports in the face of the valve 14 are surrounded by a leakage groove 52 and pads 53. The Specification states that an automatic throttle valve may be used to control the pressure to the balance port in accordance with the variations of centrifugal force. Specification 831,673 is referred to.