A bearing test method and a bearing test device are provided for bearings in
which
a non-contact state is maintained between a shaft element and a bearing element
in a normal rotation state. In addition, a motor bearing monitoring device is provided
to detect an abnormality in a motor or that a motor's life is near its end, where
the motor utilizes the bearing. Furthermore, a storage device such as a hard disk
drive equipped with the motor monitoring device is provided. For a bearing that
can retain a shaft element and a bearing element coaxially positioned in a non-contact
state when the number of revolutions exceeds a predetermined number of relative
revolutions, a bearing test method is provided to determine whether the shaft element
and the bearing element are in a contact rotation state. The bearing test method
includes at least the steps of rotating the shaft element and the bearing element
relatively with one another and detecting impedance between the shaft element and
the bearing element in the relative rotation state. A determination is made based
on a change in impedance as to whether the shaft element and the bearing element
are in a contact rotation state.