Japan Servo Co.,ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi Powdered Metals Co., Ltd.

Kouki Isozaki

Ryoso Masaki

Yuji Enomoto

Kenji Miyata

Motoya Ito

Chio Ishihara

Yasuaki Motegi

Junji Rokunohe

Tadashi Sato

Yuuichi Tsuda

Naotugu Sato

Shoji Ohiwa

Noriyoshi Kikuchi

Ayako Shimura

Yoji Unoki

Yuichi Tsuda

A claw pole type motor includes first and second claw poles opposed to each other and each including a radial yoke portion having an inner diameter side and an outer diameter side, a plurality of pole portions arranged on the inner diameter side, and axially extended, and an outer peripheral side yoke portion extending on the outer diameter side. A stator core is provided having an inner diameter side, and is formed so as to cause the pole portions of the first claw pole to be meshed with the pole portions of the second claw pole. A rotor is arranged on the inner diameter side of the stator core with a circumferential gap being defined therebetween. In order to provide high efficiency while simplifying manufacturing, the first and second claw poles are formed by compacting of magnetic powder.

Multiple phase claw pole type motor

In a multiple phase claw pole type motor which includes: a plurality of claw poles including a claw portion extending in an axial direction and having a magnetic pole surface facing a rotor in a state of being separated from the rotor by a small gap, a radial yoke portion extending radially outwardly from this claw portion, and an outer peripheral yoke extending from this radial yoke portion in the same direction as the direction of extension of the claw portion; a stator core formed by alternately placing the claw poles in a circumferential direction so that a distal end of each claw portion faces the outer peripheral yoke of an adjacent one of the claw poles; and a stator constructed by sandwiching an annular coil with the adjacent claw poles of this stator core, a multiple phase claw pole type motor characterized in that the claw poles are formed by compacting a magnetic powder and are formed of a magnetic compact having a DC magnetizing property of its flux density becoming 1.7 teslas or more when 10000 A/m of magnetic field is applied.

A stepping motor includes a first motor unit having a first stator unit and a first rotor unit and a second motor unit having a second stator unit and a second rotor unit. The first stator unit has air-core coils that are radially arranged on a first isolating magnetic disc. The first rotor unit has permanent magnets that are alternatively magnetized in N-pole and S-pole and radially arranged on a second magnetic disc with a predetermined air gap to the first stator unit. Similarly, the second stator unit has air-core coils on a third isolating magnetic disc and the second rotor unit has permanent magnets on a fourth magnetic disc. The first and second stator units are fixed to the different sides of a non-magnetic disc. The first and second rotor units are fixed to a rotation axis and face each other across the first and second stator units.

Multi-phase flat-type PM stepping motor and driving circuit thereof

Disclosed is an inner rotor or outer rotor hybrid stepping motor of 6-phase/6 m-pole type or 10-phase/10 m-pole type. The motor includes a stator that has 6 m or 10 m pieces of magnetic poles and a rotor that is rotatably supported by the stator. Excitation windings are wound around the stator magnetic poles. The stator magnetic pole is divided into two halves in the axial direction, one half has pole teeth being line-symmetric and the other half has pole teeth being asymmetric and deviated from the symmetric pole teeth by &frac14; pitch. The positions of the symmetric half and the asymmetric half are inverted between the adjacent magnetic poles. The rotor has a first and second rotor units each of which includes a permanent magnet and first and second rotor magnetic poles around which pole teeth are formed with deviation of &frac12; pitch. The first and second units are connected in the axial direction through a non-magnetic material member such that they are deviated from each other by &frac14; of rotor teeth pitch. In the case of 6 m-phase, number of the rotor pole teeth equals m(6n&plus;1) or m(6n&plus;2) where m and n are integers equal to or larger than 1.

Hybrid stepping motor

Disclosed is a multi-phase flat-type PM stepping motor comprising a first motor unit having a first stator unit and a first rotor unit, and a second motor unit having a second stator unit and a second rotor unit. The first stator unit has a plurality of air-core coils that are radially arranged on a first isolating magnetic disc. The first rotor unit has a plurality of permanent magnets that are alternatively magnetized in N-pole and S-pole and radially arranged on a second magnetic disc with a predetermined air gap with respect to the coil surface of the first stator unit. In the same manner, the second stator unit has a plurality of air-core coils that are radially arranged on a third isolating magnetic disc, and the second rotor unit has a plurality of permanent magnets arranged on a fourth magnetic disc. The first and second motor units are coaxial and symmetric with each other about a non-magnetic disc arranged therebetween.

A multi-phase outer-type permanent magnet stepping motor including a rotor constituted by a cylindrical permanent magnet assembly in which N (north) and S (south) poles are magnetized alternately on an inner circumferential surface of the rotor. Stator cores respectively having pole teeth are disposed in opposition to the N or S poles of the rotor through a predetermined gap. Further, excitation coils are wound in the stator cores for magnetizing the stator cores to thereby rotate the rotor such that, when a number of the stator cores is 3 and the magnetization pitch of the permanent magnet assembly is P, pole teeth of the stator cores are arranged so that the pole teeth of one stator core is shifted by an angle of 2P/3 from the pole teeth of an adjacent stator core.

Multi-phase outer-type PM stepping motor

A multi-phase PM-type stepping motor comprising: a rotor constituted by a cylindrical permanent magnet with N poles and S poles magnetized alternately on an outer circumferential surface of the rotor; stator cores having teeth arranged in opposition to the N poles or the S poles on the outer circumferential surface of the rotor through a predetermined air gap; and excitation coils wound in the stator cores and for magnetizing the stator cores to thereby rotate the rotor; wherein, when the number of the stator cores is represented by n (n is an odd number not smaller than 5), and the magnetization pitch angle of the permanent magnet is represented by P, the teeth of the stator cores are shifted from each other by an angle of 2P/n.

Multi-phase PM-type stepping motor

A permanent magnetic type stepping motor which is suitably used in such office automation machines and apparatuses and which parameters are set to satisfy the following conditions (1) to (4).

Growing community of inventors

Kiryu, Japan

Kouki Isozaki