A wheel rotation detecting device including a sensor unit that is supported on
a stationary ring which does not rotate even when the wheel is in use, and the
rotation of the wheel that is attached to a rotary ring can be detected by a rotation
detecting sensor held within the sensor unit. Within the sensor unit, in addition
to a rotation detecting sensor, there are disposed other sensors such as a temperature
sensor and a vibration sensor, thereby allowing detection of the rotation speed
and the rotation number of the wheel supported on the rotary ring, as well as detection
of other car driving conditions.
