US5030871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reducing harmonic losses in dynamoelectric machine rotors
Assignee: General Electric Co
•
Filing: 1990-05-11
•
Granted: 1991-07-09
•
Expires: 2010-05-11
Abstract
Abstract A solid rotor for a dynamoelectric machine including field conductors and ventilation passages in axial slots is provided with low resistivity thermally conductive axial winged inserts which seal and overlie the slots to form a low resistivity cylinder about the rotor to minimize power losses and associated heating due to harmonic induced eddy currents, enhance the conductive cooling of the rotor, and increase efficiency.
Inventors
- 👤 Manoj R. Shah
- 👤 True T. Shih
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:07
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K3/00; H02K3/04; H02K3/24; H02K1/32; H02K3/46; H02K3/48; H02K3/487
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
209 words
A rotor assembly for a dynamoelectric machine comprising: a substantially solid steel rotor including a substantially cylindrical central region adapted to rotate about an axis of rotation; conductor slots extending axially along the circumference of said central region forming at least two conductor regions separated by at least two pole regions; field conductors disposed within said conductor slots and adapted to be energized to provide magnetic poles in said pole regions; a plurality of ventilation slots extending axially along the circumference of said pole regions; said conductor slots and said ventilation slots having substantially parallel edges extending axially along the circumference of said substantially cylindrical central region; inserts retained in said conductor slots and said ventilation slots; at least the surface of said inserts being of low resistivity material as compared with the resistivity of said steel rotor; said inserts including a central portion connecting winged projections and base extensions; said winged projections overlying said edges of said conductor slots and said ventilation slots being closely adjacent one another to thereby form a substantially cylindrical low resistivity insert surface around said central region of said rotor; and slots in said rotor mating with said base extension to restrain said inserts from radial movement toward the circumference of said rotor.
Claim 2
Dependent Claim
209 words
A rotor assembly for a dynamoelectric machine comprising: a substantially solid steel rotor including a substantially cylindrical central region adapted to rotate about an axis of rotation; conductor slots extending axially along the circumference of said central region forming at least two conductor regions separated by at least two pole regions; field conductors disposed within said conductor slots and adapted to be energized to provide magnetic poles in said pole regions; a plurality of ventilation slots extending axially along the circumference of said pole regions; said conductor slots and said ventilation slots having substantially parallel edges extending axially along the circumference of said substantially cylindrical central region; inserts retained in said conductor slots and said ventilation slots; at least the surface of said inserts being of low resistivity material as compared with the resistivity of said steel rotor; said inserts including a central portion connecting winged projections and base extensions; said winged projections overlying said edges of said conductor slots and said ventilation slots being closely adjacent one another to thereby form a substantially cylindrical low resistivity insert surface around said central region of said rotor; and slots in said rotor mating with said base extension to restrain said inserts from radial movement toward the circumference of said rotor.
Claim 3
Dependent Claim
56 words
A rotor for a dynamoelectric machine of claim 1 wherein said base extensions are connected to said central portion through surfaces which extend toward said central portion and slope inwardly, and said conductor slots and said ventilation slots include cooperating sloping surfaces which restrain said inserts from radial movement away from the axis of said rotor.
Claim 4
Dependent Claim
36 words
A rotor for a dynamoelectric machine of claim 2 wherein at least some of said ventilation slots extending axially along the circumference of said pole regions are adapted to enable the flow of cooling fluid therethrough.
Claim 5
Dependent Claim
37 words
A rotor for a dynamoelectric machine of claim 3 wherein each of said winged projections include a curved surface remote from said axis of rotation to provide a peripherally extending arc of said substantially cylindrical insert surface.
Claim 6
Dependent Claim
27 words
A rotor for a dynamoelectric machine of claim 1 wherein said substantially cylindrical insert surface overlies in excess of 90 percent of the circumference of said rotor.
Claim 7
Dependent Claim
45 words
A rotor for a dynamoelectric machine of claim 1 wherein the radial depth of said ventilation slots extending axially along the circumference of said pole regions is less than the radial depth of said conductor slots, and form ventilation passages in cooperation with said inserts.
Claim 8
Dependent Claim
31 words
A rotor for a dynamoelectric machine of claim 1 wherein said inserts are high strength copper alloys having a lower resistivity and higher thermal conductivity than said substantially solid steel rotor.
Claim 9
Dependent Claim
29 words
A rotor for a dynamoelectric machine of claim 1 wherein said inserts include a cross section in the radial direction about said axis of rotation which is approximately I-shaped.
Claim 10
Dependent Claim
41 words
A rotor for a dynamoelectric machine of claim 8 wherein said conductor slots and ventilation slots include grooves extending axially and substantially parallel to the surface of said rotor forming a substantially T-shaped cross-section to restrain said inserts within said grooves.
Claim 11
Dependent Claim
36 words
A rotor for a dynamoelectric machine of claim 9 wherein said base extensions of said inserts form base surfaces which are smaller than the surfaces of said winged projections which are remote from said base surfaces.
Claim 12
Dependent Claim
43 words
A rotor for a dynamoelectric machine of claim 10 wherein said base surfaces of said inserts are substantially planar, and said conductor slots and said ventilation slots include sloping surfaces which restrain said inserts from radial movement upon rotation of the dynamoeletric machine.
Claim 13
Dependent Claim
24 words
A rotor for a dynamoelectric machine of claim 1 wherein at least one retaining ring surrounds the circumference of said substantially cylindrical insert surface.
Claim 14
Dependent Claim
36 words
A rotor for a dynamoelectric machine of claim 12 wherein said inserts are highly thermally conductive compared to said rotor to conduct rotor heat to said substantially cylindrical insert surface for cooling of said rotor assembly.
Claim 15
Dependent Claim
16 words
A rotor for a dynamoelectric machine of claim 13 wherein said inserts are a copper alloy.
Claim 16
Dependent Claim
45 words
A rotor for a dynamoelectric machine of claim 1 wherein the inner regions of said ventilation slots remote from said edges are rounded and in cooperation with said base extensions of said inserts form substantially semi-circular cross section passages for the flow of cooling fluid.
References Cited (Backward Citations)
DE313830C
Cited
DE327519C
Cited
US3324324A
Cited
FR2049487A5
Cited
US3866070A
Cited
US4843271A
Cited
US4900964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |