Rolling bearing unit

A rolling bearing unit comprising:

• a rolling bearing including an inner ring and an outer ring, one of which is a rotary ring, the other of which is a fixed ring, which rotate relative to each other, and a plurality of rolling elements disposed rotatably interposed between an outer ring raceway formed on an inner surface of the outer ring and an inner ring raceway formed on an outer surface of the inner ring;
• a sensor device for detecting the load imposed axially on the rolling bearing, the sensor device having a detecting portion for detecting the load imposed axially on the rolling bearing, and at least a part of a transmitting device for transmitting an output signal outputted from the detecting portion or a signal obtained by processing the output signal as a wireless signal;
• a supporting member for supporting the sensor device, fitted in and supported by a member in which the outer ring or inner ring as the fixed ring is fitted in such an arrangement that it is opposed to an axial end of the outer ring or inner ring as the fixed ring;
• and
• a member having at least a part of a receiving device for receiving the wireless signal transmitted from the transmitting device, the member being separately formed from the supporting member,
• wherein the detecting portion of the sensor device detects the load imposed axially on the supporting member by the outer ring or inner ring as the fixed ring to detect the load imposed axially on the rolling bearing.