Patent US4742259A successfully refreshed from Google Patents.
US4742259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet rotor for electric motor
Assignee: Franklin Electric Co Inc
•
Filing: 1987-05-11
•
Granted: 1988-05-03
•
Expires: 2007-05-11
Abstract
Abstract A rotor comprising a rotor shaft and a rotor core on the shaft, the core being cylindrical. A number of arcuate permanent magnets are positioned at angularly spaced positions on the outer periphery of the core, and a tubular metal sleeve is positioned around the magnets. The sleeve extends beyond the axially outer ends of the magnets and the sleeve has end portions which extend radially inwardly and overlie the ends of said magnets. The sleeve has residual tension which produces a radially inwardly directed force on the magnets, and the end portions are spun or turned over and produce a force on the ends of the magnets.
Inventors
- 👤 Edward J. Schaefer
- 👤 Thomas K. Antrim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:41
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2753; H02K1/278; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T29/49908; Y10T29/49915
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
A permanent magnet rotor for an electric motor, comprising an axially extending rotor shaft, a cylindrical rotor core formed on said shaft, a plurality of permanent magnets positioned at angularly spaced positions on the outer periphery of said core, and a thin tubular metal sleeve positioned around said magnets, said sleeve having residual tension and thereby pressing said magnets tightly against said core, said sleeve having a greater axial length than said core and including integral end portions which extend axially beyond the ends of said core, said integral end portions turning radially inwardly and tightly against the outer ends of said magnets.
Claim 2
Dependent Claim
103 words
A permanent magnet rotor for an electric motor, comprising an axially extending rotor shaft, a cylindrical rotor core formed on said shaft, a plurality of permanent magnets positioned at angularly spaced positions on the outer periphery of said core, and a thin tubular metal sleeve positioned around said magnets, said sleeve having residual tension and thereby pressing said magnets tightly against said core, said sleeve having a greater axial length than said core and including integral end portions which extend axially beyond the ends of said core, said integral end portions turning radially inwardly and tightly against the outer ends of said magnets.
Claim 3
Dependent Claim
17 words
A rotor according to claim 1, wherein said end portions further overlap end portions of said core.
Claim 4
Dependent Claim
46 words
A rotor according to claim 1, and further including an annular washer at each end of said rotor, said washers overlapping the ends of said magnets and portions of said core, and said end portions of said sleeve extending across the outer sides of said washers.
Claim 5
Dependent Claim
40 words
A rotor according to claim 3, wherein each of said washers engages at its outer periphery an end portion of said sleeve and at its inner periphery said rotor shaft, and said washers form a tight fit with said shaft.
Claim 6
Dependent Claim
25 words
A rotor according to claim 4, and further including sealing means between said washers and said end portions and between said washers and said shaft.
Claim 7
Dependent Claim
15 words
A rotor according to claim 3, and further including fan blades formed on said washers.
Claim 8
Dependent Claim
21 words
A rotor according to claim 6, wherein said fan blades are integrally formed on and extend axially outwardly from said core.
Claim 9
Dependent Claim
33 words
A rotor according to claim 1, wherein adjacent magnets are angularly spaced, and further including a plurality of radially outwardly extending projections on said core, said projections extending between sides of adjacent magnets.
References Cited (Backward Citations)
DE681348C
Cited
US2836743A
Cited
US3221194A
Cited
US3246187A
Cited
US3292023A
Cited
US3482131A
Cited
US3531670A
Cited
US3968390A
Cited
US4137884A
Cited
US4227105A
Cited
US4219752A
Cited
US4417167A
Cited
US4242610A
Cited
US4311933A
Cited
WO1982000117A1
Cited
EP0043981A1
Cited
JPS57180358A
Cited
US4388545A
Cited
US4433261A
Cited
US4494028A
Cited
US4564777A
Cited
US4625135A
Cited
US4628891A
Cited
US4633113A
Cited
US4674178A
Cited
US4631435A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |