| 摘要 |
1,172,917. Axial-flow fans. EUROTECHNI OFFICE EUROPEEN D'ETUDES ET DE REALISATIONS TECHNIQUES and S. E. R. M. A. G. SOC. D'ETUDES ET DE RECHERCHES MAGNETIQUES. June 23, 1967 [June 27,1966], No.29234/67. Heading F1C. [Also in Division H2] A heat engine ventilating device comprises, fixed respectively to a driven fan rotor 7 and a coaxial shaft 1 driven by the engine to be cooled, two magnetic coupling members capable of conveying torque without mechanical contact and one of which is an inductor having at least two complementary poles which magnetizes the other, induced, member which is of a permanent magnet material having a hysteresis cycle providing a slip coupling drive of the rotor beyond a predetermined maximum torque. This provides a substantially constant fan speed above a certain engine speed, and in the embodiment shown the induced member, a disc 4 of hysteretic alloy e. g. cobalt steel, is screwed or adhered to driving a pulley 3, and the driven, inductor, member is a ring shaped magnet 5 e. g. of barium ferrite adhered in the rotor 7 which is mounted on the shaft 1 by bearings 9, 10. In other embodiments the induced member is a cylinder surrounding either a cross-shaped inductor magnet (5b Fig. 8) or an axially magnetized annulus (14) having interpenetrating teeth (17, 18 Fig. 6); alternatively, the positions of the inductor and induced members can be reversed, and the inductor may be an electromagnet. |
