US4528473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet type step motor
Assignee: SHINANO KENSHI A CORP OF JAPAN KK
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Filing: 1984-02-24
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Granted: 1985-07-09
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Expires: 2004-02-24
Abstract
Abstract A permanent magnet type step motor comprising a rotor wherein a disc-like permanent magnet having a magnetic pole in an axial direction and a pair of rotor yokes holding the permanent magnet therebetween are integrally and coaxially mounted on a rotational shaft, and a stator having a stator core opposed to an outer circumference of the rotor yokes. The front and rear brackets are formed of a non-magnetic material in which a thin shield sheet of magnetic material is inserted therein, and the magnetic resistance between the rotor yokes and the ends of the brackets opposed thereto is increased to reduce the leaky magnetic flux from the motor.
Inventors
- 👤 Katsue Tezuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:31
CPC Classifications
H; H02; H02K; H02K5/00; H02K5/04; G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; H02K11/00; H02K11/01; H02K11/014; H02K11/0141; H02K37/00; H02K37/10; H02K37/12; H02K37/14; H02K37/18
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
109 words
A permanent magnet type step motor comprising: a rotor comprised of a disc-like permanent magnet having a magnetic pole in an axial direction thereof and a pair of rotor yokes holding the permanent magnet therebetween such that the rotor and the rotor yokes are integrally and coaxially mounted on a rotational shaft, and a stator having a stator core opposed to an outer circumference of said rotor yokes, said stator being coaxially held with respect to the rotational shaft by front and rear brackets, said front and rear brackets being formed of a non-magnetic material in which a thin magnetic shield sheet is embedded in the interior thickness thereof.
Claim 2
Dependent Claim
109 words
A permanent magnet type step motor comprising: a rotor comprised of a disc-like permanent magnet having a magnetic pole in an axial direction thereof and a pair of rotor yokes holding the permanent magnet therebetween such that the rotor and the rotor yokes are integrally and coaxially mounted on a rotational shaft, and a stator having a stator core opposed to an outer circumference of said rotor yokes, said stator being coaxially held with respect to the rotational shaft by front and rear brackets, said front and rear brackets being formed of a non-magnetic material in which a thin magnetic shield sheet is embedded in the interior thickness thereof.
Claim 3
Dependent Claim
26 words
A permanent magnet type step motor according to claim 1 wherein said non-magnetic material for said front and rear brackets comprises aluminum, zinc or synthetic resin.
Claim 4
Dependent Claim
51 words
A permanent magnet type step motor according to claim 2 wherein said front and rear brackets respectively comprise a cylindrical portion, a side portion for closing an opening at one end of said cylindrical portion, and a collar portion constituting a bearing housing in the inner surface of said side portion.
Claim 5
Dependent Claim
73 words
A permanent magnet type step motor according to claim 1 wherein said front and rear brackets respectively comprise a cylindrical portion, a side portion for closing an opening at one end of said cylindrical portion, and a collar portion constituting a bearing housing in the inner surface of said side portion, and wherein said shield material extends into said cylindrical portion and said side portion and does not extend into said collar portion.
Claim 6
Dependent Claim
51 words
A permanent magnet type step motor according to claim 1 wherein said front and rear brackets respectively comprise a cylindrical portion, a side portion for closing an opening at one end of said cylindrical portion, and a collar portion constituting a bearing housing in the inner surface of said side portion.
Claim 7
Dependent Claim
112 words
A step motor comprising: a rotary shaft; a rotor connected to the rotary shaft for rotation therewith; a stator having a set of energizeable drive coils wound thereon and operative in response to energization thereof to rotationally drive the rotor in a stepwise manner; front and rear casing sections connected to the stator and defining a casing which encases the rotor, at least one of the casing sections having bearing means for rotatably mounting the rotary shaft, and the front and rear casing sections being composed of a non-magnetic material; and a thin shield sheet composed of magnetic material completely embedded within the interior thickness of the front and rear casing sections.
Claim 8
Dependent Claim
112 words
A step motor comprising: a rotary shaft; a rotor connected to the rotary shaft for rotation therewith; a stator having a set of energizeable drive coils wound thereon and operative in response to energization thereof to rotationally drive the rotor in a stepwise manner; front and rear casing sections connected to the stator and defining a casing which encases the rotor, at least one of the casing sections having bearing means for rotatably mounting the rotary shaft, and the front and rear casing sections being composed of a non-magnetic material; and a thin shield sheet composed of magnetic material completely embedded within the interior thickness of the front and rear casing sections.
Claim 9
Dependent Claim
30 words
A step motor according to claim 6; wherein the non-magnetic material of the front and rear casing sections is selected from the group consisting of aluminum, zinc, and synthetic resin.
Claim 10
Dependent Claim
68 words
A step motor according to claim 7; wherein the front and rear casing sections each have a cylindrical portion, a side portion connected to and closing one end of the cylindrical portion, and a collar portion connected to and extending inwardly of the side portion; and wherein the thin shield is embedded within the cylindrical and side portions only and not the collar portion of each casing section.
Claim 11
Dependent Claim
30 words
A step motor according to claim 8; wherein both the front and rear casing sections have bearing means mounted on the collar portions thereof for rotatably mounting the rotary shaft.
Claim 12
Dependent Claim
20 words
A step motor according to claim 9; wherein the front and rear casing sections each comprise a one-piece unitary structure.
Claim 13
Dependent Claim
20 words
A step motor according to claim 6; wherein the front and rear casing sections each comprise a one-piece unitary structure.
Claim 14
Dependent Claim
68 words
A step motor according to claim 11; wherein the front and rear casing each have a cylindrical portion, a side portion connected to and closing one end of the cylindrical portion, and a collar portion connected to and extending inwardly of the side portion; and wherein the thin shield sheet is embedded within the cylindrical and side portions only and not the collar portion of each casing section.
Claim 15
Dependent Claim
30 words
A step motor according to claim 12; wherein both the front and rear casing sections have bearing means mounted on the collar portions thereof for rotatably mounting the rotary shaft.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |