Sanyo Denki Co., Ltd.

Satoru Onodera

Toshihito Miyashita

Manabu Matsushita

Akira Shimizu

Hiroshi Hioki

Kazuyuki Kitazawa

Kazuhiko Takizawa

Hideyuki Ishii

Masahiro Koyama

A permanent magnet rotary motor is provided in which cogging torque can be reduced and an increase in copper loss can also be prevented. A first divided core unitis combined with a second divided core unit, thereby constituting a stator core. The first divided core unitconstitutes a yoke portion. The second divided core unitincludes pole pieces, magnetic pole surface constituent portions, and first and second type connecting portionsA andB each mutually couple two adjacent magnetic pole surface constituent portionsall of which are formed integral with one another. The thickness of the first type connecting portionsA in a radial direction of the stator coreis set to be smaller than the thickness of the second type connecting portionsB in the radial direction of the stator core

Permanent magnet rotary motor

An interior permanent magnet rotary motor of the present invention has N slots and P permanent magnet magnetic pole sections, (&#x2154;&#x3c;=P/N&#x3c;= 43/45). Po is an irreducible fraction Po/No of the P/N is an odd number, and a pole arc ratio &#x3c8;equals &#x3b8;pp/&#x3b8;p. &#x3b8;pp is an angle between two line segments assumed for a pair of flux barriers, each of which connects the center of a rotor core and one of corners of the section of each flux barrier that is closest to the surface of the rotor core. &#x3b8;p is an angle obtained by dividing 360&#xb0; by the number of the permanent magnet pole sections. The pole arc ratio indicated by &#x3a8;(0&#x3c;4n&#x3c;1) is determined by the expression of &#x3a8;=2mP/N+P/4LCM (P, N)&#x2212;2n, where LCM (P, N) is the least common multiple between P and N, m and n are arbitrary natural numbers.

Method of determining pole arc ratio of interior permanent magnet rotary motor and interior permanent magnet rotary motor

A permanent magnet rotary motor that can maintain higher torque density and reduce cogging torque more greatly than a conventional permanent magnet rotary motor. A pair of end surfaces of each of permanent magnets used for a rotor are substantially parallel to a virtual plane that extends in the radial direction of a rotor core while passing through the centers of a stator core and an arc surface. Then, the length of the arc surface in the peripheral direction of a rotor core and inclinations of inclined surfaces are so determined that a pole arc ratio &#x3a8;of the arc surface and a pole arc ratio &#x3a8;of a magnetic pole surface in each permanent magnet satisfy the relation of P/2N&#x2266;&#x3a8;&#x2212;&#x3a8;&#x2266;1.38&#xd7;P/2N.

An interior permanent magnet synchronous motor wherein cogging torque and torque pulsation during feeding of electricity can be both restrained. 2p (p: a positive integer of 1 or more) magnetic salient pole sections consists of two groups of magnetic salient pole sections, a first group of which consists of p magnetic salient pole sections arranged so as to be spaced at equal intervals in the peripheral direction while having one magnetic salient pole section of a second group interposed between each of two adjacent magnetic salient pole sections, and the second group of which consists of p magnetic salient pole sections arranged so as to be spaced at equal intervals in the peripheral direction while having one magnetic salient pole section of the first group interposed between each of two adjacent magnetic salient pole sections. The open angle &agr;1 of the p magnetic salient pole sections of the first group is smaller than the open angle &agr;2 of the p magnetic salient pole sections of the second group. Then the open angles &agr;1 and &agr;2 are set to satisfy the expression &agr;2&minus;&agr;1&ap;2&bgr;&minus;(2n&minus;1)&tgr;s. n is a natural number. &bgr; is an angle between virtual center lines CL and CL of two adjacent magnetic salient pole sections which extend from the center of the shaft through the center of each salient magnetic pole sections. &tgr;s is the slot pitch of the stator core.

Interior permanent magnet synchronous motor

It is an object of the present invention to provide a motor having a structure so as to prevent the peeling off of adhesive for fixing the bearing. The outer ring of the second ball bearing is fitted into the second ball bearing fitting space of the bearing holder portion of the second end bracket. The annular leaf spring which gives a pressure in the direction toward the first end bracket to the outer ring of the second ball bearing is disposed in the pressure giving structure receiving space which is formed continuously to the second ball bearing fitting space. The annular leaf spring is shaped such that trough and crest portions appear alternately in the circumferential direction. The screw members are inserted into the screw holes formed in the second end bracket. The tip end portions of the screw members are arranged to abut the trough portions of the annular leaf spring.

Motor with a shaft supported by ball bearings

An interior permanent magnet synchronous motor capable of significantly restraining cogging torque and torque pulsation during feeding of electricity thereto. Each of the outer peripheral surface sections of a rotor core and a magnetic pole surface of each of magnetic poles of a stator core are arranged so as to have a gap defined therebetween and having a size &dgr;d which satisfies an expression &dgr;d&equals;&dgr;d /cos(p&thgr;d), wherein &dgr;d is a size of the gap which is determined along a virtual center line defined so as to extend through centers of two virtual lines extending from a center of a shaft through both ends of the outer peripheral surface section defined in a peripheral direction thereof and &thgr;d is an angle between the virtual central line and each of the virtual lines.

Growing community of inventors

Nagano, Japan

Satoru Onodera