GB711572A - Improvements in vibration damping means for bladings in fluid actuated or actuating rotary machines - Google Patents

Abstract

711,572. Turbine and compressor blades. SOC.- RATEAU and ANXIONNAZ. R. Feb. 12, 1952 [Feb. 27,1951], No. 3741/52. Class 110(3) In a turbine or axial-flow compressor, the rotor blades have laterally-projecting members on both sides of each blade integral therewith and capable of elastic deformation in a radial plane with respect to the rotational axis of the blades when subjected to centrifugal force thereby effecting vibration damping. The projections on two adjacent blades are adapted to be unequally deformed by centrifugal force and are arranged so that they bear one on another in frictional engagement at the rotational speed at which vibrations occur, but have a clearance i there between at other speeds. The projections d, e in Fig. 1 are of unequal lengths b, e and are shaped to provide small resistance to flow of the working fluid. The clearance between the two projections may be zero when the rotor is at rest, clearance occurring as the result of centrifugal force. A plurality of concentric rows of projections a, e, d<SP>1</SP>, e<SP>1</SP> may be provided as in Fig. 6, or projections in accordance with the invention may be combined with another form of vibration damping means as in Fig. 7, the damping wire 1 being in accordance with Specification 708,836. In the embodiment shown in Fig. 8 the second form of vibration damping means comprises small blocks 2 housed in holes through the blades, the blocks having their ends formed as abutments and the blocks can move slightly relatively to the blades, the friction between the parts assisting in damping vibrations.