To perform easily a mounting/dismounting work of a sensor 12 of a bearing device with a rotational speed detection device, and to install the sensor firmly on a sensor holder.
This device has a constitution wherein the front wall 9b of a sensor insertion part 9 of the sensor holder 6 into which the sensor 12 is to be inserted has a cam surface wherein the distance to the front surface of the sensor 12 is gradually expanded downward, and a roller 16 and a spring 15 for energizing the roller 16 upward are integrated in a wedged space formed between the front surface of the sensor 12 and the cam surface. When the sensor 12 is pushed into the sensor insertion part 9, the spring 15 is contracted and the roller 16 is moved to a position out of the wedged space, and the roller 16 is returned to the interlocking position in the wedged space by a spring force at the insertion finish point of time, to thereby prevent drawing-out of the sensor 12. When drawing out the sensor 12 from the sensor insertion part 9, the roller 16 interfitted in the wedged space is pushed down by a pushing-down member 17 to remove wedge coupling of the roller 16, and thereby the sensor 12 can be drawn out easily from the sensor insertion part 9.
NORIMATSU TAKAYUKI
Higashio Masahiro
Torii Kazuhisa