Non-contact measuring unit for transmitter wheel rotation speed and its direction

摘要

The surface of the transmitter wheel (1) facing the sensor (2) has a reflecting structure. This structure includes at least one asymmetrical three dimensional profile (4), and the optical sensor (2) measures a distance (d) between the optical sensor, fixed mechanically relative to the transmitter wheel (1) and the surface profile (4) of the wheel. The profile (4) is designed in a saw tooth shape. The optical sensor (2) includes a transmitter (5) and a receiver (6). The receiver (6) reflects the light emitted from the transmitter (5), at the surface profile (4) of the transmitter wheel (1). So that it detects the proportional light for the distance (d) between the surface profile (4) and the receiver (6). The processing unit (3) produces a signal proportional to the rotational speed and the direction of rotation, from the intensity of the reflected light.