GB1433748A - Magnetic induction couplings - Google Patents

Abstract

1433748 Magnetic couplings PYE Ltd 7 Sept 1973 [25 Sept 1972] 44282/72 Addition to 1261894 Heading H2A The magnetic induction coupling of the parent Specification includes a rotor 1 with axial polepieces mounted on a first shaft 14; a disc 7 of non-ferromagnetic material mounted on a second shaft 9; and a stator 5 with an extension 16 forming both a surrounding casing and a return path for the magnetic flux, the extension 16 definining with the outer periphery of the rotor 1 a radial airgap 19. This coupling which includes an energizing coil 6 on the stator 5 is modified in one or more of the following respects: (a) holes and passages are provided for the circulation of cooling fluid, e.g. air, in the divided flow path shown arrowed; (b) the energizing coil 6 is mounted on spacers and formed with gaps to facilitate circulation of the cooling fluid; (c) the energizing coil is tapered, e.g. trapezoidal, in radial cross-section; (d) the effect of the energizing coil is supplemented or opposed by one or more permanent magnets; (e) a flywheel 51 is fitted to the output shaft 9 within a casing extension 16a; (f) the face position 4 of the stator 5 is laminated; and (g) the disc 7 is insulated from its supporting hub 8 by a heat insulating ring 50 of asbestos cement or ceramic material. With regard to (a) an external fan or pump may assist fluid flow; with regard to (e) the periphery of the flywheel may be grooved or notched to co-operate with a sensor to act as a tachometric device; and with regard to (f) the laminations may extend in radical or axial planes.