Bearing with wireless self-powered sensor unit

A tapered roller bearing having its rollers arranged in two rows within an outer race and around an inner race contains a sensing device that radiates signals which reflect conditions within the bearing. In one embodiment, the outer race is unitary and the sensing device is wireless and self-powered and includes a mounting ring that is fitted to the outer race between the raceways along which the rollers roll. The ring has embedded within it several sensors for monitoring bearing conditions such as temperature and vibrations. The ring also contains a radio transmitter, a microprocessor to which the sensors are connected, and a power supply for producing the electrical energy required to operate the processor and the transmitter. The electric power is generated by means of electromechanical energy conversion using permanent magnets, armature winding and a target wheel that is captured between and rotates with the two cones. The transmitter converts conditions registered by the sensors and processed by the processor into radio signals which are received externally from the bearing. In another embodiment the unitary outer race has a groove which opens inwardly between the two rows of rollers, and the sensors, radio transmitter, processor, and power supply are located within the groove. In other embodiments the inner race is unitary and the sensors, radio transmitter, processor and power supply are carried by the inner race.