| 摘要 |
1,207,348. Bearings. ROBERT BOSCH G.m.b.H. 15 Nov., 1967 [16 Nov., 1966], No. 51891/67. Heading F2A. [Also in Division H2] A bearing fault detecting device in a rotary electrical machine, e.g. a vehicle A.C. generator, comprises a stationary substantially annular contact 28 coaxial with the rotor axis and so engageable with a contact 27 rotatable with the rotor 11 that a conductive connection is made between the contacts when the rotor is displaced radially by a distance less than the length of the air gap 30 between the rotor and stator 20. In the embodiment shown, the contact 28 is a ring formed by an extension of the bearing plate 22, and the contact 27 is an extension of a slip ring 15 conveying current to an excitation winding 14 between claw polepieces 12, 13. Both bearings may have such a device and a protective layer 29 may be applied to one ring and the other ring roughened. In a modification, the outer contact 28 is hexagonal. Visual warning of a fault is given by a changing indicator lamp 40 connected between the outputs A, B of two rectifier stalks 31, 34 respectively feeding a battery 32 and other loads 33, and the winding 14; such fault shorts the winding and the lamp is lit by the battery. The device is also applicable to generators having permanent magnet rotors (46) in which case, Fig. 8, a warning device, e.g. a dashboard lamp is operated by a relay (49) connected between the contacts 27, 28 and a 3 ph. stator winding (47) feeding a bridge rectifier (48) which may be controllable. The rings 27, 28 may be of sintered bronze in order to act as emergency bearings. |
