Patent GB-843188-A (GB)
Title: Improvements in and relating to rotary pumps and/or motors
IPC: F04C2/344
Filed: 1957-02-15
Abstract: 843,188. Rotary pumps. FRASER, A. May 15, 1958 [Feb. 15, 1957], No. 5322/57. Class 110(2). A pump in which outwardly sliding vanes cooperate with more than one abutment has the rotor mounted on a shaft of non-circular section, the section being symmetrical about at least two planes passing through the centroid of the section and the rotor being provided with a complementary opening which receives the shaft with an easy sliding fit. Preferably the section is elliptical. A stator ring 10 is clamped between annular walls 11, 12 which house bearings 17, 17<SP>1</SP> for the shaft 16, which has a hub 19 supporting the rotor 18. One end of the shaft 16 extends through an end cap 14 and is joined by a flexible coupling 21 to a driving shaft 22. The other end of the rotor shaft is a hollow tube communicating with an inlet port 24 in an end cap 13. The outer surface of the rotor 18 is cylindrical and the inner surface of the stator has six equispaced abutments 27 whose radius of curvature is approximately the same as that of the rotor. The liquid chambers 28 between the abutments are formed by peripheral part-cylindrical surfaces 26 of the stator having a radius of curvature greater than the rotor. Four equispaced radial ducts 29 communicate through ducts 30 in the shaft 16 with the inlet 24. Ahead of each duct 29 and parallel therewith is a slot 31 housing a vane 32 thrust against the stator 10 by a spring 321 and the side edges of each vane bear against the walls 11, 12. Each vane has in its leading edge longitudinal grooves 33 to form ducts which communicate with ducts 34 in the rotor opening into annular channels 35 in the stator walls 11, 12, each channel 35 being connected to a discharge port 36 by way of an annular duct 37. Thus liquid entering through the port 24 passes through the ducts 30, 29 into the chambers 28 and is forced by the vanes 32 into the grooves 33 and through the ducts 34 to the outlets 36. High-pressure leakage between the rotor and the stator wall 11 drains to the inlet, while high-pressure leakage between the rotor and the wall 12 drains into a chamber 40 in the cap 14 communicating through a duct 38 with the inlet 24. A seal 41 preventing the escape of fluid along the shaft 16 comprises a metal collar 42 on which is mounted an annular rubber pad 43 carrying a carbon ring 44 which bears against an annular surface 45 inside the cap 14 and is maintained in position by a spring 42<SP>1</SP> bearing against the seal. A liquid-tight seal between the collar 42 and the shaft is provided by resilient bands 47. The coupling 21 comprises two metal collars 48, one on shaft 16 and one on shaft 22, to which are bonded rubber collars 50, a metal sleeve 49 being bonded to each rubber collar. Sleeve 49 is elliptical internally to conform to the surfaces of the collars 48 and the shafts. Circlips 51 hold the collars in position on the shafts. A modification is described in which the section is four-sided, the sides and corners being rounded. The section may also be three-sided. Specification 733,547 is referred to.