Rolling bearing apparatus and detection method for abnormality in rolling bearing

A detection method for detecting an abnormality in a rolling bearing, the detection method comprising:

• calculating a value for vibration of the rolling bearing and a rotation speed of the rolling bearing based on a detection signal from a vibration detector, the vibration detector being attached to a fixed ring that is concentrically provided in the rolling bearing together with a rotating ring;
• and
• detecting abnormality in the rolling bearing,
• wherein:
• calculating the value for vibration and the rotation speed includes calculating the rotation speed based on frequency components of the vibration and the number of vibrations inherent in the rolling bearing, and
• detecting the abnormality includes detecting the abnormality based on an amplitude at a peak frequency obtained from the frequency components.

A rolling bearing apparatus comprising:

• a bearing main body having a fixed ring and a rotating ring that are concentrically provided and a plurality of rolling elements provided between the fixed ring and the rotating ring;
• a vibration detector attached to the fixed ring;
• and
• a calculation unit for calculating a value for vibration of the bearing main body,
• wherein:
• the vibration detector inputs a voltage signal, which serves as a detection signal corresponding to the vibration of the bearing main body, to the control unit,
• the calculation unit samples the input voltage signal to determine a waveform, and executes frequency analysis on the waveform to obtain frequency components,
• the calculation unit stores at least one number of excitations,
• the calculation unit rectifies the voltage signal received from the vibration detector to obtain a DC output and determines a range of rotation speeds from the voltage of the DC output, and
• the calculation unit divides each of the peak frequencies by one pre-stored number of excitations to determine rotations speeds and to determine one of the rotation speeds that corresponds to the range to be the rotation speed of the bearing main body.