| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulse motor whose primary side slider has an equivalent pitch skew construction, which can avoid a phase discrepancy regardless of the direction of stepping and whose propulsive force waveform is not distorted. SOLUTION: The positive direction equivalent pitch skew part 13P and negative direction equivalent pitch skew part 13N of a slider 13 which practices step movement on a scale 11 are connected in series to each other. In the positive direction equivalent pitch skew part 13P, while the teeth 11a of the scale 11 are arranged with pitchesτ, two pole teeth 13a are arranged with a pitch of (τ+ΔX) for each pole (U-phase pole 13U, etc.). In the negative direction equivalent pitch skew part 13N, two teeth 13a are arranged with a pitch of (τ+ΔX) for each pole (U'-phase pole 13U', etc.). With this constitution, a phase discrepancy in the stepping direction of the positive direction equivalent pitch skew part 13P and a phase discrepancy in the stepping direction of the negative direction equivalent pitch skew part 13N cancel each other, so that the phase discrepancy can be avoided and the distortion of a propulsive force waveform can be also avoided.
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