GB1233966A - - Google Patents

Abstract

1,233,966. Machines with permanent magnets. KELSEY-HAYES CO. 24 Feb., 1969 [1 July, 1968], No. 9863/69. Heading H2A. A tachometer for sensing the speed of a first member which is rotatable relative to a second member comprises a rotor connectible to the first member and a stator connectible to the second member, the stator being mounted for radial movement in a given direction in response to movement of the rotor in that direction, the rotor movement being caused by movement of the first member relative to the second in the same direction. The tachometer shown is mounted on a vehicle axle assembly and comprises a rotor 70 mounted on a shaft 14 and a stator 50 mounted by means of resilient clips 34 on a plate 26 secured to a bearing housing 20. Radial movement of the rotor 70 (caused by radial deflection of the shaft) results in a smooth cylindrical part 76, Fig. 2, of the rotor engaging a smooth surface 68 on the stator, thus moving the stator against the action of the spring clips so as to maintain a predetermined minimum distance between teeth 54 and 74 on the stator and rotor respectively. A lug 44, on a non-magnetic stator housing 30, engaging a slot 46 in the plate 26 permits radial but prevents angular movement of the stator. The tachometer is of the inductor type with a permanent magnet and an output coil 56 both on the stator. In a modification (not shown), the part 76 of the rotor bears directly on the surface 68 of the stator, even during normal running.