| 摘要 |
<p>A speed sensor comprising a core (3) as a magnetic body having a U-shaped cross section, sensing coils (4a and 4b) which are wound around the core (3) and convert a change in the magnetic flux density in the core (3) into an electric signal, a magnetoelectric transducing unit (1) having permanent magnets (2a and 2b) at both ends of the core (3) for supplying a magnetic flux to the core (3), and a sensing plate (8) which is a disc-shaped magnetic body which rotates synchronously with an object to be sensed, and has recesses (8b) and projections (8a) formed sequentially in the circumferential direction at the edge face, in which a magnetic path is formed together with the core via the recesses (8b) and the projections (8a). The magnetoelectric transducing unit is so disposed that the end of the core faces the edge face of the sensing plate via a predetermined air gap and disposed as a set at a predetermined interval corresponding to the interval between each recess (8b) and each projection (8a) of the sensing plate (8). With the construction, the very reliable small speed sensor having a high electromotive force, little fluctuation in the gap caused by thermal expansion, and no danger of a wire break, which does not occupy a large area, is easily installed and adjusted, and can obtain two signals having a phase difference can be realized.</p> |
