Abstract: An electromagnetic bearing includes a canning arrangement (30, FIG. 2) for separating stator coils 33 from a suspension gap 21 containing gas at high pressure. The canning arrangement comprises a bridging member 38.sub.1 . . . in each cell slot 31.sub.1, 32.sub.2 . . . supported on notches 37 cut from the edges of bounding pole pieces 31.sub.1, 32.sub.2 . . . , the surface of which bridging member facing the rotor comprises a support face set radially outwardly of the pole faces. A thin, deformable can member 40 is supported on the pole faces and deforms outwardly in response to pressure difference between suspension gap and coil slot into contact with the bridging members and locates the can member and bridging members. The can and bridging members may be formed of stainless steel and deformation may be plastic.

Abstract: A damping arrangement 20 (FIG. 1(b)) for radial vibrations in a turbomachine shaft 10 comprise two circumferentially limited, diametrically opposed damping chambers 22, 23 open towards the shaft and to which gas is supplied alternately by gas flow controllers 29.sub.A and 29.sub.B. Each controller contains fluidic devices switched by sensing pressures in the circumferentially displaced chambers 22', 23', or even the same chambers, as such pressure are modulated by the variations in shaft position, to divert the gas from source 27. The diversion of gas flow is arranged to cause pressure fluctuations, which exert radial thrust on the shaft, advanced in phase to approach of the shaft so as to damp the vibration. The fluidic devices may be implemented by flow amplifiers or fluid logic flip flop 41 (FIG. 2) and may be multistage devices to increase gain, all of which may be formed without moving parts and embedded in the housing.

Abstract: A damping arrangement (FIG. 1) for axial vibrations in a turbomachine shaft 10 comprises at least one circumferentially extending annular damping chambers 34 and 35 open towards a shaft thrust face 19.sub.A and 19.sub.B of a radially extending collar 20 and to which gas is supplied alternately by gas flow controllers 42.sub.A and 42.sub.B. Each controller contains fluidic devices switched by sensing pressures in radially displaced pressure sensing chambers 51, 53, or even the same chambers, as such pressure are modulated by the variations in shaft and collar position, to divert the gas from source 40. The diversion of gas flow is arranged to cause pressure fluctuations, which exert axial thrust on the thrust faces, advanced in phase to approach of the shaft so as to damp the vibration. The fluidic devices may be implemented by flow amplifiers 47.sub.A, 47.sub.B or fluid logic flip flop 61 (FIG.

Abstract: A damping arrangement 25 (FIG. 1) for damping axial vibrations in a shaft suspended (optionally) by a magnetic bearing has a radially extending thrust face 24 mounted on the shaft and separated by a small face gap 29 from a housing 30 and through which gap a stream of gas is forced by way of a flow restrictor 31 at the entrance to the gap. The flow restrictor acts with thrust face 26 to define a gap entrance related to the axial position/displacement of the shaft. A chamber 33, defined downstream of the restrictor and having exhaust passage 35, opens at neck 34 to face the thrust face and the gas pressure therein exerts axial thrust on the shaft. Axial vibration of the shaft modulates gas supply to the face gap and the chamber is dimensioned to create a phase lead of 90.degree. for the instantaneous pressure therein and axial thrust on the shaft, thus damping the shaft vibrations causing its displacement.