| 摘要 |
<p>An electric stepper motor of the kind having a cylindrical permanently magnetised rotor (1) providing equally angularly spaced poles of successively opposite polarity around its circumference and a stator (19) providing pole pieces (35, 37) around the rotor at corresponding angular spacings and arranged for energisation by an electric current so that the stator pole pieces are magnetised with successively opposite polarity. The surfaces of the pole pieces (35, 37) facing the rotor (1) are skewed so that the spacing between the rotor and the facing surface of each pole piece increases in a given direction around the rotor axis, thereby to ensure that the rotor rotates in a predetermined direction each time the direction of the stator energisation current is reversed.</p> |
