US4952859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepping motor
Assignee: Canon Inc
•
Filing: 1988-11-30
•
Granted: 1990-08-28
•
Expires: 2008-11-30
Abstract
Abstract A stepping motor characterized by the provision of an anisotropic resin magnet rotor which is the rotor of the motor and comprises an anisotropic resin magnet and which has recesses formed at the centers of the magnetic poles thereof and in which the wave form of the magnetic force is one of a two-head wave form and a trapezoidal wave form in the range of 0.1-0.2 of the air gap between the rotor and stator teeth during the use of the motor.
Inventors
- 👤 Akira Torisawa
- 👤 Katsumi Yoshida
- 👤 Hiroshi Koizumi
- 👤 Hiroyuki Yoshikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:42
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/10; H02K37/12; H02K37/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
178 words
A stepping motor comprising: a rotor having a cylindrical surface, a shaft and a plurality of N poles and S poles magnetized on the cylindrical surface, said poles each being provided with a recess at the center portion thereof; a stator unit including a first stator member and a second stator member, said first stator member having a first yoke member provided with a plurality of first teeth arranged arcuately along the outer periphery of said rotor, a second yoke member provided with a plurality of second teeth separated from said first teeth by a predetermined pitch, and a first coil for magnetizing said first and second teeth, said second stator member being disposed at a position opposed to said first stator member with said rotor disposed therebetween, said second stator member having a third yoke member provided with a plurality of arcuately arranged third teeth and a fourth yoke member provided with a plurality of fourth teeth separated from said third teeth by said predetermined pitch, and a second coil for magnetizing said third and fourth teeth.
Claim 2
Dependent Claim
178 words
A stepping motor comprising: a rotor having a cylindrical surface, a shaft and a plurality of N poles and S poles magnetized on the cylindrical surface, said poles each being provided with a recess at the center portion thereof; a stator unit including a first stator member and a second stator member, said first stator member having a first yoke member provided with a plurality of first teeth arranged arcuately along the outer periphery of said rotor, a second yoke member provided with a plurality of second teeth separated from said first teeth by a predetermined pitch, and a first coil for magnetizing said first and second teeth, said second stator member being disposed at a position opposed to said first stator member with said rotor disposed therebetween, said second stator member having a third yoke member provided with a plurality of arcuately arranged third teeth and a fourth yoke member provided with a plurality of fourth teeth separated from said third teeth by said predetermined pitch, and a second coil for magnetizing said third and fourth teeth.
Claim 3
Dependent Claim
63 words
A stepping motor according to claim 1, wherein said recesses are formed so that the distribution curve of strength of magnetic flux from each magnetic pole of said rotor is a double-peaked wave form or a trapezoidal wave form, and the number of the coggings of said rotor is thereby made greater than the number of the magnetized magnetic poles of said rotor.
References Cited (Backward Citations)
US3014141A
Cited
US3549918A
Cited
US3496393A
Cited
US3860843A
Cited
US3866104A
Cited
US4255696A
Cited
US4174485A
Cited
US4381465A
Cited
US4504755A
Cited
US4656381A
Cited
US4601564A
Cited
US4672253A
Cited
US4704292A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |