Wireless sensor system, and bearing apparatus with wireless sensor

[0052] In the next place, application of the wireless sensor system to the machine setup will be described in detail with particular reference to FIG. 4. In this example, the machine setup 53 includes a plurality of rolling bearing assemblies 51 and 52, which are equipped with the respective wireless sensor units 4A and 4B shown and described in connection with any one of the embodiments of FIGS. 1 and 2. The machine setup 53 is in the form of, for example, a conveyor line including, for example, roller conveyors or belt conveyors, in which rotary shafts 59, each forming a shaft for transport rollers or belt drive rollers, are rotatably supported respectively by the rolling bearing assemblies 51 and 52. Each of the rolling bearing assemblies 51 and 52 is of a type including a circular row of rolling elements 56 interposed between an inner race 54 and an outer race 55 and provided with a sealing member 58 and is in the form of a deep groove ball bearing assembly or the like. The rollin

[0074]FIG. 11 illustrates an application of the wireless sensor system shown in and described with reference to FIG. 10 to the wheel support bearing assembly 33, in which the wireless sensor unit 4 is mounted on the outer member 1. In this example, the plural sensor sections 6C to 6E are used to detect the number of revolutions, the temperature and the vibration, respectively. As the sensor sections 6D and 6E, a preload sensor, a load sensor and a torque sensor may be provided in place of the above.

[0075] The sensor section 6C serving as a revolution sensor includes a magnetic encoder 17 containing a multipolar magnet mounted externally on the inner member 2 and a magnetic sensor 18 in the form of, for example, a Hall sensor or an MR sensor mounted internally on the outer member 1 in face-to-face relation with the magnetic encoder 17. The transmitting and receiving unit 7 is mounted externally on the outer member 1. This transmitting and receiving unit 7 has circuit elements accommoda