| abstract |
(57) [Summary] [PROBLEMS] While having a rotation speed detection function, there is no possibility of disconnection outside the vehicle, and further downsizing, avoidance of wiring complexity, and improvement of sealing performance of a bearing can be obtained. Provided is a wheel bearing device. SOLUTION: A double-row rolling element 3 is interposed between an outer member 1 and an inner member 2. A generator 4 for generating electric power by the relative rotation between the outer member 1 and the inner member 2 is provided. Generator 4 Is a coil-magnetic body set 1 in which a coil is housed in a ring member 7 and a multipole magnet 18. Transmission means 5 for wirelessly transmitting a signal of the number of rotations of the wheels 13 output from the generator 4 is provided. The transmitting means 5 may have an annular transmitter. |