GB845793A - Gas-lubricated shaft bearings - Google Patents

Abstract

845,793. Bearings. SULZER FRERES S.A. Feb. 17, 1958 [Aug. 30, 1957], No. 5109/58. Class 12 (1). In order to avoid secondary rotation of the axis of a rotor shaft 3 about the axis of a fixed bearing 1 of a gas-supported bearing, e.g. for a high-speed machine with a low weight rotor, an intermediate member in the form of a bush 2 having a mass much smaller than that of the rotor 3 is inserted, with clearance gaps 4, 5, between the bearing 1 and the rotor 3, secondary rotation of the rotor then occurring only at a relatively high speed lying beyond the normal operational speeds of the machine. During operation gas under pressure passes through passages 6 in the bearing 1 to the gaps 4 and then through passages 7 in the bush 2 to the inner gap 5 from which it emerges at 8, 9, the bush being rotatable but held against axial movement. In a modification the bush has a number of circumferentially-spaced, longitudinal, passages, each of which communicates with a main-gas-passage in the fixed bearing and has a number of radial outlets leading to the space 5, the bush, radially movable, being secured by a stud against rotation. The stud may be omitted so that the bush can rotate the main-gas passages, in this case, leading to an annular channel extending around the inner surface of the fixed bearing. The bush may be coupled to the shaft 3 by a key, the stud being dispensed with. If desired, gas at a different pressure from that supplying the passages 6 can be introduced into the main-gas passages. In a further modification, Fig. 5, part-cylindrical members 16, accommodated with clearance gaps 4<SP>11</SP>, 511 in correspondingly-shaped recesses 17 in the fixed bearing 1<SP>11</SP>, are rotatable about axes 21, their cylindrical surfaces 19 supporting the rotor 3. During operation the rotor 3 and the members 16 are supported by gas introduced under pressure into the gaps 4<SP>11</SP>, 5<SP>11</SP>, the members 16 having passages 14, 15, 7<SP>11</SP> for leading the gas to the gaps 5. Alternatively, the passages 15, 7<SP>11</SP> can be fed with pressure gas from the gaps 4<SP>11</SP>, on the passages 6<SP>11</SP>, in which case the passages 14 can be omitted. In a still further modification, each segment has a longitudinal recess along one edge, pressure gas being introduced into the gaps 4 and, if desired, through passages provided in the elements 16 to supply gas to the gaps 5.