Patent US5032746A successfully refreshed from Google Patents.
US5032746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear motor with driving device
Assignee: Sharp Corp
•
Filing: 1989-03-20
•
Granted: 1991-07-16
•
Expires: 2009-03-20
Abstract
Abstract A linear motor is capable of reducing cogging which may be present in the motor. Cogging is an obstruction in realizing constant speed control or high accuracy of position control. The reduction of cogging is accomplished for example by pole location or specific detailed shaping of pole iron plates.
Inventors
- 👤 Tetuyuki Ueda
- 👤 Hiroshi Ishii
- 👤 Masayoshi Tsunezawa
- 👤 Masaaki Ozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:12
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; H02K41/031; H02K2213/00; H02K2213/03
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
A linear motor which comprises: a stator field member having a plurality of permanent magnets and a yoke; a movable member having polyphase windings and a magnetic pole iron plate arranged to confront said stator field member in a plane, in order to relatively displace said movable member with respect to said stator field member by polyphase exciting of said polyphase windings; said magnetic pole iron plate having a geometrical shape obtained by dividing said magnetic pole iron plate into two rectangular regions of equal size and configuration with respect to a geometrical center axis in a displacing direction of said linear motor; and displacing said rectangular regions in a parallel relation in the forward and backward directions of displacement of said linear motor.
Claim 2
Dependent Claim
124 words
A linear motor which comprises: a stator field member having a plurality of permanent magnets and a yoke; a movable member having polyphase windings and a magnetic pole iron plate arranged to confront said stator field member in a plane, in order to relatively displace said movable member with respect to said stator field member by polyphase exciting of said polyphase windings; said magnetic pole iron plate having a geometrical shape obtained by dividing said magnetic pole iron plate into two rectangular regions of equal size and configuration with respect to a geometrical center axis in a displacing direction of said linear motor; and displacing said rectangular regions in a parallel relation in the forward and backward directions of displacement of said linear motor.
Claim 3
Dependent Claim
49 words
A linear motor as claimed in claim 1, wherein the parallel displacing amount of the rectangular regions in the magnetic pole iron plate having a length of [n+(1/2)]p is represented by p/4, where n is a natural number, and p is a pole pitch of said stator field member.
Claim 4
Dependent Claim
49 words
A linear motor as claimed in claim 1, wherein the parallel displacing amount of the rectangular regions in the magnetic pole iron plate having a length of np is represented by p/4, where n is a natural number, and p is a pole pitch of said stator field member.
References Cited (Backward Citations)
DE2413410A1
Cited
DE2946147A1
Cited
DE3123441A1
Cited
JPS57209507A
Cited
JPS5863074A
Cited
JPS5875458A
Cited
US4629916A
Cited
US4724350A
Cited
JPS6469252A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |