GB892391A - Improvements relating to dynamo-electric machines - Google Patents

Abstract

892,391. Fluid bearings. MACKS, E. F. May 29, 1959, No. 18399/59. Class 12 (1). [Also in Group XXXV] In a dynamo-electric machine the rotor 10 and stator 14 have smooth complementary cylindrical surfaces, the radial spacing between them being such that when the rotor operates, a film of ambient fluid such as air formed between the surfaces supports the rotor in the radial direction. In a modification a sleeve of non- magnetic material is placed inside the stator, the film being formed between it and the rotor (Fig. 2, not shown). When the rotor is mounted vertically, an end-plate on the stator co-operates with the end of the rotor to form a thrust-bearing film (Fig. 3, not shown). To obtain such a film the end of the rotor or the stator end-plate is modified to have segments recessed below the plane of the surface (Fig. 4, not shown). The segments do not extend completely from rim to centre of the surface so reducing end leakage. A ball-type thrust bearing may be provided to support the rotor vertically (Fig. 5, not shown). In a further modification the rotor 10 has a bore 36, concentric with rotor shaft 12 and into which fits stud 38 fixed to the stator 14, the film being formed between bore and stud. Similar modifications may be made having ball thrust bearings between rotor and stator housing (Figs. 8, 9, not shown) and when the rotor is mounted vertically the end of the stud is recessed as described above. In another modification the shaft 12 has an enlarged portion 40 adjacent the rotor to co-operate with a bracket 41 fixed to the stator to form the film. To prevent axial movement of rotor and stator a stop-bracket coacts with an extension on the rotor shaft (Fig. 12, not shown). When this modification is mounted vertically a thrust-bracket on the enlarged shaft portion co-operates with the end of the stator bracket to form a thrust-bearing film (Fig. 13, not shown).