US5886440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor with plural rotor portions having pole members of different widths
Assignee: Aisin AW Co Ltd
•
Filing: 1997-05-16
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Granted: 1999-03-23
•
Expires: 2017-05-16
Abstract
Abstract A motor capable of suppressing the torque ripple includes a rotor, a stator and stator coils. The rotor is provided with a plurality of permanent magnets which are arranged at a constant pitch in the circumferential direction. The stator surrounds the rotor and is formed with a plurality of stator poles and a slot located between every two stator poles. The stator coils are wound on the stator and are supplied with three-phase sinusoidal current. The rotor is composed of a plurality of rotor portions which are arranged in the axial direction of the rotor. The difference between the open angle of each permanent magnet of one rotor portion and the open angle of each permanent magnet of another rotor portion is an integral multiple of 30° in electrical angle. When three-phase sinusoidal current is applied to the stator coils, a torque ripple is generated. However, the phase of a torque ripple generated at one of the rotor portions arranged in the axial direction can be made different from the phase(s) of torque ripple(s) generated at other rotor portion(s).
Inventors
- 👤 Masahiro Hasebe
- 👤 Yasuo Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:22
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2753; H02K1/278; H02K19/00; H02K19/02; H02K19/10; H02K19/103; H02K21/00; H02K21/12; H02K21/14; H02K2201/00; H02K2201/06
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
208 words
A motor comprising: a rotor provided with a plurality of permanent magnets which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in an axial direction of said rotor and which have respective different circumferential widths of the permanent magnets, the difference between one end surface in the circumferential direction of each permanent magnet in one rotor portion and one end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in another rotor portion being +15°×n+360°×k in electrical angle and the difference between the other end surface in the circumferential direction of each permanent magnet in the one rotor portion and the other end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 2
Dependent Claim
208 words
A motor comprising: a rotor provided with a plurality of permanent magnets which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in an axial direction of said rotor and which have respective different circumferential widths of the permanent magnets, the difference between one end surface in the circumferential direction of each permanent magnet in one rotor portion and one end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in another rotor portion being +15°×n+360°×k in electrical angle and the difference between the other end surface in the circumferential direction of each permanent magnet in the one rotor portion and the other end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 3
Dependent Claim
54 words
A motor according to claim 1, wherein the difference between the circumferential width of each permanent magnet in the one rotor portion and the circumferential width of each permanent magnet of the same polarity in the another rotor portion is an odd multiple of a mechanical pitch angle of the slots of said stator.
Claim 4
Dependent Claim
60 words
A motor according to claim 1, wherein each of the permanent magnets of each of said rotor portions is a salient pole, and the difference between the circumferential width of each salient pole of the one rotor portion and the circumferential width of each salient pole of the another rotor portion is an integral multiple of 30° in electrical angle.
Claim 5
Dependent Claim
12 words
A motor according to claim 3, wherein the numeral n is 1.
Claim 6
Dependent Claim
54 words
A motor according to claim 1, wherein the difference between the circumferential width of each salient pole in the one rotor portion and the circumferential width of each salient pole of the same polarity in the another rotor portion being an odd multiple of a mechanical pitch angle of the slots of said stator.
Claim 7
Dependent Claim
12 words
A motor according to claim 1, wherein the numeral n is 1.
Claim 8
Dependent Claim
210 words
A motor comprising: a rotor provided with a plurality of permanent magnets which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in the circumferential direction of said rotor and which have respective different circumferential widths of the permanent magnets, the difference between one end surface in the circumferential direction of each permanent magnet in one rotor portion and one end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in another rotor portion being -15°×n+360°x k in electrical angle and the difference between the other end surface in the circumferential direction of each permanent magnet in the one rotor portion and the other end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in the another rotor portion being -15°×n+360°x k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 9
Dependent Claim
210 words
A motor comprising: a rotor provided with a plurality of permanent magnets which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in the circumferential direction of said rotor and which have respective different circumferential widths of the permanent magnets, the difference between one end surface in the circumferential direction of each permanent magnet in one rotor portion and one end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in another rotor portion being -15°×n+360°x k in electrical angle and the difference between the other end surface in the circumferential direction of each permanent magnet in the one rotor portion and the other end surface in the circumferential direction of each corresponding permanent magnet of the same polarity in the another rotor portion being -15°×n+360°x k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 10
Dependent Claim
54 words
A motor according to claim 7, wherein the difference between the circumferential width of each permanent magnet in the one rotor portion and the circumferential width of each permanent magnet of the same polarity in the another rotor portion is an odd multiple of a mechanical pitch angle of the slots of said stator.
Claim 11
Dependent Claim
60 words
A motor according to claim 7, wherein each of the permanent magnets of each of said rotor portions is a salient pole, and the difference between the circumferential width of each salient pole of the one rotor portion and the circumferential width of each salient pole of the another rotor portion is an integral multiple of 30° in electrical angle.
Claim 12
Dependent Claim
12 words
A motor according to claim 9, wherein the numeral n is 1.
Claim 13
Dependent Claim
12 words
A motor according to claim 7, wherein the numeral n is 1.
Claim 14
Dependent Claim
202 words
A motor comprising: a rotor provided with a plurality of salient poles which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in an axial direction of said rotor and which have respective different circumferential widths of the salient poles, the difference of each salient pole in one rotor portion and one end surface in the circumferential direction of each corresponding salient pole of the same polarity in another rotor portion being +15°×n +360°×k in the electrical angle and the difference between the other end surface in the circumferential direction of each salient pole in the one rotor portion and the other end surface in the circumferential direction of each corresponding salient pole of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 15
Dependent Claim
202 words
A motor comprising: a rotor provided with a plurality of salient poles which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in an axial direction of said rotor and which have respective different circumferential widths of the salient poles, the difference of each salient pole in one rotor portion and one end surface in the circumferential direction of each corresponding salient pole of the same polarity in another rotor portion being +15°×n +360°×k in the electrical angle and the difference between the other end surface in the circumferential direction of each salient pole in the one rotor portion and the other end surface in the circumferential direction of each corresponding salient pole of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 16
Dependent Claim
54 words
A motor according to claim 12, wherein the difference between the circumferential width of each salient pole in the one rotor portion and the circumferential width of each salient pole of the same polarity in the another rotor portion is an odd multiple of a mechanical pitch angle of the slots of said stator.
Claim 17
Dependent Claim
12 words
A motor according to claim 12, wherein the numeral n is 1.
Claim 18
Dependent Claim
208 words
A motor comprising: a rotor provided with a plurality of salient poles which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in the circumferential direction of said rotor and which have respective different circumferential widths of the salient poles, the difference between one end surface in the circumferential direction of each salient pole in one rotor portion and one end surface in the circumferential direction of each corresponding salient pole of the same polarity in another rotor portion being +15°×n+360°×k in electrical angle and the difference between the other end surface in the circumferential direction of each salient pole in the one rotor portion and the other end surface in the circumferential direction of each corresponding salient pole of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 19
Dependent Claim
208 words
A motor comprising: a rotor provided with a plurality of salient poles which are arranged at a constant pitch in a circumferential direction of the rotor; a stator which surrounds said rotor and is formed with a plurality of stator poles and a slot located between every two stator poles; and stator coils which are wound on said stator and are supplied with three-phase sinusoidal current; said rotor being formed by a plurality of rotor portions which are arranged in the circumferential direction of said rotor and which have respective different circumferential widths of the salient poles, the difference between one end surface in the circumferential direction of each salient pole in one rotor portion and one end surface in the circumferential direction of each corresponding salient pole of the same polarity in another rotor portion being +15°×n+360°×k in electrical angle and the difference between the other end surface in the circumferential direction of each salient pole in the one rotor portion and the other end surface in the circumferential direction of each corresponding salient pole of the same polarity in the another rotor portion being -15°×n+360°×k in electrical angle wherein n is an integer greater than 0 and k is 0 or an integer greater than 0.
Claim 20
Dependent Claim
12 words
A motor according to claim 15, wherein the numeral n is 1.
References Cited (Backward Citations)
US4847526A
Cited
US4751415A
Cited
JPS648853A
Cited
JPH01122353A
Cited
JPH01122352A
Cited
JPH01286758A
Cited
US5038065A
Cited
US5095238A
Cited
US5386161A
Cited
JPH0686524A
Cited
US5396137A
Cited
US5510662A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-22 | 2002-09-21 | 2003-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-22 | 2006-09-21 | 2007-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-22 | 2010-09-21 | 2011-03-23 | $7700.00 | Window Closed / Lapsed |