Stepping motor, printing device using it or paper feeding device, and printer
AssigneeSeiko Epson Corporation
InventorsAkihiko Ikegami, Yoshikazu Koike
Life of this patent
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Abstract
A stepping motor (1) which has rotor pole teeth (31) disposed with a predetermined pitch (P1) on a rotor (3) and stator pole teeth (22) formed on a stator pole (21) so to oppose the rotor pole teeth (31), wherein the stator poles (21) are provided with n sets of tooth groups (23) consisting of the stator pole teeth (22) in the number of m, a pitch P2 of the stator pole teeth (22) in the tooth groups (23) is in the relation P2≠P1, and a pitch P3 of the tooth groups (23) is in the relations P3≠m·P1 and P3≠m·P2 (where, P1, P2 and P3 denote an electrical angle, and m and n are integers of 2 or more), and a three-phase stepping motor in which the fourth harmonic and the sixth harmonic are decreased.
Claims6
A stepping motor comprising a stator having a plurality of stator poles and a rotor disposed to oppose the stator poles with a space therebetween, the rotor having rotor pole teeth disposed with a predetermined pitch P1 and the stator poles having stator pole teeth opposed to the rotor pole teeth, wherein:
- each of stator poles is provided with n sets of tooth groups, each group consisting of the stator pole teeth in the number of m,
- a pitch P2 of the stator pole teeth in the tooth groups meets the following formula:
- P2≠P1,
- and a pitch P3 of the tooth groups meets the following formulas:
- P3≠m·P2
- P3≠m·P2
- where, P1, P2 and P3 denote electrical angles, and m and n are integers of 2 or more, thus reducing harmonics of a plurality of orders within each of the stator poles.
A three-phase stepping motor comprising a stator having a plurality of stator poles and a rotor disposed to oppose the stator poles with a space therebetween, the rotor having rotor pole teeth disposed with a predetermined pitch PR and the stator poles having stator pole teeth opposed to the rotor pole teeth, wherein:
- each of stator poles is provided with the stator pole teeth in the number of m,
- a pitch PS of the stator pole teeth meets the following formula:
- PS=PR{1±i/(m·4)},
- and
- PS=PR{1±i′/(m·6)},
- where, i and i′ are positive integers which are not a multiple of m.
Dependencies are inferred from the claim text.