| 摘要 |
<p>An electromagnetic clutch provided with electromagnetic means for measuring the rotational speed of the clutch rotor, is comprising at least one coil 17 which is integral with the fixed electromagnet 7a of the clutch and a device (a gap or a permanent magnet 19) integral with the rotor such that on rotation of the rotor an electromagnetic signal is generated which can be detected by the coil, with further electrical and electronic devices to activate mechanical means of protection and/or indication if the detected speed differs from normal operating values specified for the part driven by the rotor. The clutch may drive auxiliary apparatus, such as an air- conditioning compressor, in a car or a power take-off of a tractor. <IMAGE></p> |
