| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor which has a rotor position detecting means of a high accuracy as an integral part of it, and which can generate high output while the outer diameter is kept small. SOLUTION: A first and a second magnetized layer constituting a permanent magnet ring 1 have a cylindrical shape and are divided into (n) pieces in the circumferential direction, which are magnetized in different magnetic poles alternately, and are 180 deg./n out of phase from each other. Such a permanent magnet ring 1 is fixed on a rotary shaft 2 to constitute a rotor. Concentrically with and adjacently to the permanent magnet ring 1, a first and a second coil 3, 4 are located on the rotary shaft 2 with the rotor being put between these coil in the axis direction. The coils 3, 4 have a first and a second cylindrical soft magnetic material-made yoke 5, 6 respectively which are so inserted into inner parts of the magnetized layers that they may face corresponding parts of the inner faces of the magnetized layers of the magnet ring 1. Then, a soft magnetic material-made third yoke 7 is so located as to cover parts of the outer faces of the coils 3, 4 and magnet ring 1. At a specified space from a part of the outer face of the magnet ring which is not covered by the third yoke, a Hall element 11 for detecting the rotor position is so installed as to face that part. |
