| 摘要 |
PURPOSE:To achieve a temperature measurement by using a coil winding of a transducer of a wheel speed sensor as a part for detecting sensitivity. CONSTITUTION:A sensor 36 comprises a magnetic ring 38 as rotor and a circular transducer 40 as stator to detect the rotational speed of a wheel. A coil 62 is provided in a transducer and when the magnetic ring 38 rotates relatively, an AC voltage is induced in a coil 62 by an alternating magnetic field flowing through the transducer. On the other hand, a voltage set with a voltage setter 92 connected to a battery power source 94 is applied to a resistor 96 as reference resistor and a coil winding 62 as variable resistor whose resistance value varies with temperature. The reactance of the coil winding 62 is measured by the voltage of a sensor 98. While the relative rotation of the magnetic ring 38 fails, a voltage output measured with the sensor 98 corresponds to the temperature of the coil winding 62 while the magnetic ring 38 rotates, an AC signal is detected with the sensor 98. A DC bias corresponds to a resistance value, namely, the temperature of the coil winding 62. This enables the measurement of the temperature of a bearing apparatus 10. |
