| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of detecting the malfunction such as separation of a bearing with a rotation sensor without increasing the number of sensors, and to provide its device. SOLUTION: The automobile wheel bearing 1 has the rotation sensor 21 for outputting a pulse waveform as a rotation detecting signal. Herein, a duty ratio computing means 32 is provided for computing the duty ratio of the output waveform of the rotation sensor 21 and a malfunction determining means 33 is provided for determining the malfunction of the wheel bearing 1 from the computed duty ratio in accordance with a set criterion. The rotation sensor 21 consists of a magnetism encoder 23 mounted on a rotation side member 4 of the wheel bearing 1 and a magnetism sensor mounted on a fixation side member 3 for detecting the magnetic pole of the magnetism encoder 23. The duty ratio computing means 32 computes the duty ratio of the output waveform of the rotation sensor 21 for each of pulses adjacent to each other. The malfunction determining means 33 computes the amount of a change of the duty ratio for each pulse. It determines the malfunction of the bearing when the amount of the change exceeds a threshold value or when frequencies that the amount of the change exceeds the threshold value are detected to be more than set. COPYRIGHT: (C)2006,JPO&NCIPI
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