US5095237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sectoral core for magnetic bearing
Assignee: NOVA Corp OF ALBERTA A CORP OF CANADA
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Filing: 1991-01-10
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Granted: 1992-03-10
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Expires: 2011-01-10
Abstract
Abstract A rotary electrical machine comprises a rotor assembly and a stator assembly separated by an air gap. The stator is formed from discrete generally pie-shaped pole pieces having a progressively increasing radial slot to accommodate winding of the coil. The pole pieces are preferably wound from a grain oriented ferromagnetic tape to improve the permeability of the pole and its saturation level. Groups of poles may be separated into sectors. In an alternative embodiment, at least some of the pole pieces are formed from both a permanent magnet and ferromagnetic tape to provide a constant bias between the rotor and stator assemblies.
Inventors
- 👤 Theodor Bardas
- 👤 Gordon Brailean
- 👤 Timothy A. Harris
- 👤 Vaclav Kulle
- 👤 Cal Oleksuk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:12
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/044; F16C32/0459; F16C32/0461; F16C32/0465; F16C32/0474; F16C32/048; H; H02; H02K; H02K7/00; H02K7/08; H02K7/09
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
181 words
A radial magnetic bearing comprising a rotor assembly secured to and rotating with rotating components of said bearing and a stator assembly secured to stationary components of said bearing, said assemblies having opposed peripheral surfaces separated by an air gap with said stator assembly comprising a plurality of pole pieces arranged in seriatim about the axis of rotation of said machine, each pole piece being formed as a discrete unit and having a pair of circumferentially spaced limbs, each of which terminates in a pole at the respective peripheral surface, said limbs being separated by a radial slot extending from an axially extending discontinuity in the peripheral surface that separates the poles and having a portion of greater circumferential width than said discontinuity, said pole pieces being segregated into at least two sectors, each containing an integral number of pole pieces, each sector having means associated therewith for generating and adjusting the magnetic flux in the pole pieces of its respective sector independently of the adjacent sectors and thereby adjusting the force exerted by the respective sector on said rotor assembly.
Claim 2
Dependent Claim
181 words
A radial magnetic bearing comprising a rotor assembly secured to and rotating with rotating components of said bearing and a stator assembly secured to stationary components of said bearing, said assemblies having opposed peripheral surfaces separated by an air gap with said stator assembly comprising a plurality of pole pieces arranged in seriatim about the axis of rotation of said machine, each pole piece being formed as a discrete unit and having a pair of circumferentially spaced limbs, each of which terminates in a pole at the respective peripheral surface, said limbs being separated by a radial slot extending from an axially extending discontinuity in the peripheral surface that separates the poles and having a portion of greater circumferential width than said discontinuity, said pole pieces being segregated into at least two sectors, each containing an integral number of pole pieces, each sector having means associated therewith for generating and adjusting the magnetic flux in the pole pieces of its respective sector independently of the adjacent sectors and thereby adjusting the force exerted by the respective sector on said rotor assembly.
Claim 3
Dependent Claim
39 words
A magnetic bearing according to claim 1 wherein each of said generation and adjustment means includes a coil means and current supply means, said coil means encompassing at least a portion of each pole piece in the respective sector.
Claim 4
Dependent Claim
22 words
A bearing according to claim 2 wherein said slot progressively increases in width in a radial direction away from said peripheral surface.
Claim 5
Dependent Claim
14 words
A bearing according to claim 3 wherein said limbs converge toward said peripheral surface.
Claim 6
Dependent Claim
19 words
A bearing according to claim 4 wherein said pole pieces are pie-shaped and limbs of adjacent pole pieces abut.
Claim 7
Dependent Claim
24 words
A bearing according to claim 5 wherein said coil means includes a coil encompassing abutting limbs of adjacent pole pieces in the respective sector.
Claim 8
Dependent Claim
39 words
A bearing according to claim 6 wherein each sector is delimited by a pole piece having a limb abutting a limb of a pole piece of an adjacent sector, said coil encompassing the other limb of said pole piece.
Claim 9
Dependent Claim
43 words
A bearing according to claim 1 wherein at least a portion of at least one of said pole pieces is formed from laminations extending between said poles and abutting faces of said laminations lie in planes generally parallel to the axis of rotation.
Claim 10
Dependent Claim
19 words
A bearing according to claim 8 wherein said laminations are lengths of ferromagnetic tape with an oriented grain structure.
Claim 11
Dependent Claim
25 words
A bearing according to claim 9 wherein each of said pole pieces are pie-shaped and said limbs are interconnected by a circumferentially extending connecting portion.
Claim 12
Dependent Claim
17 words
A bearing according to claim 10 wherein said limbs and connecting portion have a substantially uniform cross-section.
Claim 13
Dependent Claim
16 words
A bearing according to claim 11 wherein limbs of adjacent pole pieces in each sector abut.
Claim 14
Dependent Claim
26 words
A bearing according to claim 12 wherein said coil means includes a coil encompassing abutting pairs of limbs of adjacent pole pieces in the respective sector.
Claim 15
Dependent Claim
20 words
A bearing according to claim 9 wherein at least one of said pole pieces is formed entirely from said laminations.
Claim 16
Dependent Claim
23 words
A bearing according to claim 1 wherein at least one of said pole pieces is formed in part from a permanently magnetized material.
Claim 17
Dependent Claim
33 words
A bearing according to claim 8 wherein selected ones of said pole pieces are formed at least in part from material exhibiting enhanced magnetic characteristics relative to the other of said pole pieces.
Claim 18
Dependent Claim
201 words
A rotary electrical machine comprising a rotor assembly secured to and rotating with rotating components of said machine and a stator assembly secured to stationary components of said machine, said assemblies having opposed peripheral surfaces separated by an air gap, said stator assembly comprising a plurality of pole pieces arranged in seriatim about the axis of rotation of said machine, each pole piece having a pair of spaced limbs each of which terminates in a pole at the respective peripheral surface, at least one of said pole pieces being formed at least in part from laminations extending between said poles with abutting faces of said laminations being in planes generally parallel to the axis of rotation of said rotating assembly, said pole pieces being pie-shaped with a correspondingly-shaped radial slot between said limbs, said slot extending to said peripheral surface to define a discontinuity therein to separate said poles, at least one pair of abutting limbs being encompassed by a coil formed from multiple turns of a conductor arranged in layers, said turns being located in the radial slots of each of said pair of pole pieces and said layers having a cumulative thickness greater than the discontinuity between said limbs.
Claim 19
Dependent Claim
201 words
A rotary electrical machine comprising a rotor assembly secured to and rotating with rotating components of said machine and a stator assembly secured to stationary components of said machine, said assemblies having opposed peripheral surfaces separated by an air gap, said stator assembly comprising a plurality of pole pieces arranged in seriatim about the axis of rotation of said machine, each pole piece having a pair of spaced limbs each of which terminates in a pole at the respective peripheral surface, at least one of said pole pieces being formed at least in part from laminations extending between said poles with abutting faces of said laminations being in planes generally parallel to the axis of rotation of said rotating assembly, said pole pieces being pie-shaped with a correspondingly-shaped radial slot between said limbs, said slot extending to said peripheral surface to define a discontinuity therein to separate said poles, at least one pair of abutting limbs being encompassed by a coil formed from multiple turns of a conductor arranged in layers, said turns being located in the radial slots of each of said pair of pole pieces and said layers having a cumulative thickness greater than the discontinuity between said limbs.
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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) | 1995-03-10 | 1995-09-09 | 1996-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-10 | 1999-09-09 | 2000-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-10 | 2003-09-09 | 2004-03-10 | $7700.00 | Window Closed / Lapsed |