GB680792A - Improvements in or relating to arrangements for balancing axial thrusts on turbo-machine rotors - Google Patents

Abstract

680,792. Elastic-fluid turbines and compressors. SOC. RATEAU, and ANXIONNAZ, R. March 26, 1947 [April 29, 1946], No. 8243/47. Classes 110(i) and 110(iii) A balancing arrangement for axial thrust in either direction on the rotor of a turbine using gaseous or vapour fluid or of an axial or radial flow compressor, blower, supercharger, or pump (excluding liquid pumps), comprises a disc or drum b rigid with the shaft a and formed on each face with impeller vanes c working in separate chambers b<SP>1</SP>, b<SP>2</SP> the inlet to each of which chambers is provided by co-operating regions of the chamber walls and of the disc or drum whereby throttling passages are formed such that on the occurrence of any axial movement of the shaft a restoring thrust arises by a reduced throttling on one side of the disc or drum and an increased throttling on the other side of the drum or disc respectively causing increased and reduced pressures of a circulating balancing fluid (oil) on the; two sides of the disc or drum, the circulating balancing fluid being heavier than the fluid driving the turbine or handled by the compressor &c.. a throttling passage (which need not be variable) being provided at the discharge side of the chambers to ensure that an effective pressure is set up in the balancing space. The top half of the figure shows the disc or drum disposed in mid position while the bottom half shows it slightly displaced to the right. The inlet r<SP>2</SP> to the chamber b<SP>1</SP> is provided by a shoulder a<SP>2</SP>, formed in the shaft a, co-operating with a casing part; the discharge from the chamber b<SP>1</SP> is through a throttling passage n formed between the periphery of the disc or drum and part e on the casing. When the disc or drum moves to the right the inlet r2 is increasingly throttled while the inlet r' to the opposite-side chamber b<SP>2</SP> is opened out and thus a restoring thrust is given by the increase of pressure in the chamber b<SP>2</SP> and the decrease of pressure in the chamber b<SP>1</SP>. The Specification as open to inspection under Sect. 91, comprises also an arrangement Fig. 3 (Cancelled) in which an end thrust balancing disc b with vanes c on one side sets up pressure in a chamber provided with discharge openings k, l, m arranged at different radial distances and opened by valves h controlled by an altimeter so that the balancing and thrust (due to the heavy balancing fluid) is adjusted according to the ambient pressure of the air taken in by the axial-flow compressor &c. This subject-matter does not appear in the Specification as accepted.