US4459500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic field pole assembly
Assignee: Proterial Ltd
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Filing: 1982-05-14
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Granted: 1984-07-10
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Expires: 2002-05-14
Abstract
Abstract A magnetic field pole assembly for a direct-current motor comprises a nonmagnetic support member, a plurality of even pole pieces disposed in the support member and angularly spaced in symmetrical relationship around a central axis of the support member, a pair of permanent magnets mounted one on each side of each pole piece and having like plarities confronting each other across the pole piece, and yokes disposed between adjacent pole pieces and connected to and between those adjacent permanent magnets which are mounted on the adjacent pole pieces. Each of the permanent magnets is in the form of a plate magnetized in the direction of plate thickness and having one magnetic pole surface secured to a side of one of the pole pieces.
Inventors
- 👤 Toshinobu Miyamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:11
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/02; H02K23/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
208 words
A magnetic field pole assembly for a directcurrent motor, comprising: a non-magnetic support means; four or more even number of pole pieces angularly spaced in symmetrical relationship around a central axis of said support means and attached thereto; a number of permanent magnets equal in number to twice said even number of pole pieces, each permanent magnet having a tapered end portion and one permanent magnet being attached to a respective opposite side of a respective pole piece such that like polarities of opposing permanent magnets on each pole piece are in confronting relationship and the tapered end portions of respective permanent magnets between adjacent pole pieces are in confronting relationship; a number of yokes equal in number to said even number of pole pieces and each including a pair of leg members, each respective yoke extending between adjacent pole pieces with each leg member being attached to a respective one of the permanent magnets attached to said adjacent pole pieces; a non-magnetic end cover for closing and opening formed in the axial direction of said non-magnetic support means; and a ferromagnetic cylindrical flux return member embedded to project axially from the center of said end cover and spaced from the inward end faces of said pole pieces.
Claim 2
Dependent Claim
208 words
A magnetic field pole assembly for a directcurrent motor, comprising: a non-magnetic support means; four or more even number of pole pieces angularly spaced in symmetrical relationship around a central axis of said support means and attached thereto; a number of permanent magnets equal in number to twice said even number of pole pieces, each permanent magnet having a tapered end portion and one permanent magnet being attached to a respective opposite side of a respective pole piece such that like polarities of opposing permanent magnets on each pole piece are in confronting relationship and the tapered end portions of respective permanent magnets between adjacent pole pieces are in confronting relationship; a number of yokes equal in number to said even number of pole pieces and each including a pair of leg members, each respective yoke extending between adjacent pole pieces with each leg member being attached to a respective one of the permanent magnets attached to said adjacent pole pieces; a non-magnetic end cover for closing and opening formed in the axial direction of said non-magnetic support means; and a ferromagnetic cylindrical flux return member embedded to project axially from the center of said end cover and spaced from the inward end faces of said pole pieces.
Claim 3
Dependent Claim
25 words
A magnetic field pole assembly according to claim 1, wherein said support means is composed of a substantially cylindrical frame made of die cast aluminum.
Claim 4
Dependent Claim
22 words
A magnetic field pole assembly according to claim 2, wherein said substantially cylindrical frame is in the form of a polygonal tubing.
Claim 5
Dependent Claim
22 words
A magnetic field pole assembly according to claim 2, wherein each of the pole pieces is embedded in said non-magnetic support means.
Claim 6
Dependent Claim
21 words
A magnetic field pole assembly according to claim 1, wherein said pole pieces and yoke are made of iron or steel.
Claim 7
Dependent Claim
31 words
A magnetic field pole assembly according to claim 1, wherein said pole pieces and yoke are composed of silicon steel plates laminated in the axial direction of the magnetic pole assembly.
Claim 8
Dependent Claim
17 words
A magnetic field pole assembly according to claim 1, wherein said pole pieces are four in number.
Claim 9
Dependent Claim
16 words
A magnetic field pole assembly according to claim 7, wherein each of said yokes is L-shaped.
Claim 10
Dependent Claim
21 words
A magnetic field pole assembly according to claim 1, wherein each of said permanent magnets is made of ceramic magnetic material.
Claim 11
Dependent Claim
46 words
A magnetic field pole assembly according to claim 1, wherein each of said permanent magnets is in the form of a plate magnetized in the direction of plate thickness and having one magnetic pole surface secured to said respective opposite side of a respective pole piece.
Claim 12
Dependent Claim
24 words
A magnetic field pole assembly according to claim 1, further comprising at least one auxiliary magnet disposed adjacent to each of said permanent magnets.
Claim 13
Dependent Claim
43 words
A magnetic field pole assembly according to claim 11, wherein each of said at least one auxiliary magnet has a coercive force higher than that of each permanent magnet and is attached at the radially inward end of each of said permanent magnets.
Claim 14
Dependent Claim
29 words
A magnetic field pole assembly according to claim 11, wherein said at least one auxiliary magnet is secured to at least one axial end face of each pole piece.
Claim 15
Dependent Claim
29 words
A magnetic field pole assembly according to claim 13, wherein each of said at least one auxiliary magnet has a coercive force higher than that of each permanent magnet.
Claim 16
Dependent Claim
71 words
A magnetic field pole assembly according to claim 11, including a number of first and second auxiliary magnets, said first auxiliary magnets having a coercive force higher than that of each permanent magnet and at least one first auxiliary magnet being attached at the radially inward end of each permanent magnet and at least one second auxiliary magnet being secured to at least one axial end face of each pole piece.
Claim 17
Dependent Claim
22 words
A magnetic field pole assembly according to claim 2, wherein said substantially cylindrical frame is in the form of a cylindrical tubing.
Claim 18
Dependent Claim
18 words
A magnetic field pole assembly according to claim 1, wherein said support means is made of plastic material.
Claim 19
Dependent Claim
30 words
A magnetic field pole assembly according to claim 17, wherein each of said pole pieces, permanent magnets and yokes are retained in the plastic material of said non-magnetic support means.
Claim 20
Dependent Claim
18 words
A magnetic field pole assembly according to claim 1, wherein said support means is made of synthetic rubber.
Claim 21
Dependent Claim
22 words
A magnetic field pole assembly according to claim 1, wherein each of said permanent magnets is made of rare earth magnetic material.
References Cited (Backward Citations)
US3693037A
Cited
US3836802A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-10 | 1988-01-09 | 1988-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-10 | 1992-01-09 | 1992-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-10 | 1996-01-09 | 1996-07-10 | $7700.00 | Window Closed / Lapsed |