GB1407030A - Rotary positive displacement pump or motor - Google Patents

Abstract

1407030 Rotary positive-displacement machine A FISCHER 12 Dec 1972 [21 Dec 1971] 57268/72 Heading F1F A rotary positive-displacement pump or motor comprises an annular rotor 3 which surrounds a stator having fixed wall portions 6 and intermediate radially movable abutments 10, the rotor having part-cylindrical vanes 1 which are biased in an anti-clockwise direction 2. The wall portions 6 continuously engage the inner surface of rotor 3 and are connected to the abutments 10 by rundown and run-up portions 15, 16 which are interrupted by ducts leading to the inlet and outlet ports 18, 19. A cam ring 12 can be rotated to a predetermined fixed position to hold each abutment 10 in a fixed radial position, the abutments 10 co-operating with ring 12 via respective members 20. The radial position of abutments 10 determine the volume of working chambers 21. Each vane 1 has a passage 22 leading to a recess 23 behind the vane. In use, a vane 1 leaves wall portion 6 and travels down the run-down portion 15, continuous contact being provided by the anti-clockwise biasing means of the vane. This anti-clockwise movement assists suction of fluid from port 18, such suction being begun by the preceding vane. When a rounded edge 8 of vane 1 eventually sealingly engages abutment 10, the working chamber 21 is cut off from exhaust and fluid entering recess 23 via passage 22 acts on the back of vane 1 to assist sealing of it against abutment 10. Eventually, the preceding vane leaves abutment 10 to open up communication between the chamber 21 and outlet 19. In alternative embodiments, the rotor is located within the stator or has two portions located respectively outside and within the stator, Figs. 3 and 4 (not shown). Alternatively the annular stator can have a T or U-cross-section with one or a combination of sides being engaged by vanes of respective rotor portions, Figs. 5 to 7 (not shown).