US4629916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for harmonics suppression in motor systems
Assignee: Portescap SA
•
Filing: 1985-03-20
•
Granted: 1986-12-16
•
Expires: 2005-03-20
Abstract
Abstract A polyphase synchronous motor having a relatively large number of poles, constructed for substantial elimination of all significant harmonics. Harmonics are eliminated by dividing the motor into two symmetrical groupings, each a complete motor, then rotating one grouping relative to the other by an angle π/h electrical degrees, where h is the order of the harmonic being suppressed. Also, with a permanent magnet disc rotor, the magnet poles on one face of the disc can be rotated relative to those of the other face in the same manner, to suppress a harmonic.
Inventors
- 👤 Claude Oudet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:35
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/10; H02K37/12; H02K37/125; H02K21/00; H02K21/12; H02K21/24; H02K7/00; H02K7/20
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
166 words
A system for microstepping motor control comprising: circuit means for providing multi-phase signals proportioned to provide a plurality of step values for motor positioning between 0 and 2 electrical degrees; drive circuit means for providing poly phase energizing currents for the motor corresponding to said step values; a stepper motor including at least two phase windings connected to receive said energizing currents proportioned according to said step values, a plurality of pole pieces associated with each of said windings and providing a motor air gap, magnetic circuits for coupling said windings to said pole pieces, a rotor in said air gap being positionable in accordance with said proportioned energizing currents applied to said windings; each of said plurality of pole pieces being divided into at least one pair of substantially identical symmetrical groupings, the plane of symmetry of one grouping of a pair being shifted relative to the other grouping of the pair by an angle π/h electrical degrees, wherein h is a harmonic being suppressed.
Claim 2
Independent Claim
166 words
A system for microstepping motor control comprising: circuit means for providing multi-phase signals proportioned to provide a plurality of step values for motor positioning between 0 and 2 electrical degrees; drive circuit means for providing poly phase energizing currents for the motor corresponding to said step values; a stepper motor including at least two phase windings connected to receive said energizing currents proportioned according to said step values, a plurality of pole pieces associated with each of said windings and providing a motor air gap, magnetic circuits for coupling said windings to said pole pieces, a rotor in said air gap being positionable in accordance with said proportioned energizing currents applied to said windings; each of said plurality of pole pieces being divided into at least one pair of substantially identical symmetrical groupings, the plane of symmetry of one grouping of a pair being shifted relative to the other grouping of the pair by an angle π/h electrical degrees, wherein h is a harmonic being suppressed.
Claim 3
Dependent Claim
26 words
The system according to claim 1 for two-phase motor control, wherein said circuit is digital means and provides two-phase signals proportioned according to sine quadrature values.
Claim 4
Dependent Claim
25 words
The system according to claim 1, wherein said circuit means provides said multi-phase signals proportioned according to the motor torque/displacement characteristic with major harmonics suppressed.
Claim 5
Dependent Claim
36 words
The system according to claim 2, wherein said digital means includes a counter for indicating step position and a read only memory for providing said step values according to the step position indicated by said counter.
Claim 6
Dependent Claim
13 words
The system according to claim 2, wherein said digital means includes a microprocessor.
Claim 7
Dependent Claim
26 words
The system according to claim 1, wherein h is an odd number for suppression of the corresponding harmonic of the torque due to the electric current.
Claim 8
Dependent Claim
35 words
The system according to claim 1, wherein said stepping motor is a two-phase motor and wherein said pole pieces are divided into three different pair groupings shifted to suppress the 3rd, 4th and 5th harmonic.
Claim 9
Dependent Claim
29 words
The system according to claim 1, wherein said rotor is a thin permanently magnetized disc located in said air gap with magnetic poles on opposite faces of said disc.
Claim 10
Dependent Claim
39 words
The system according to claim 8, wherein said magnetic poles on one side of said disc are angularly displaced relative to the magnetic poles on the other side of π/h' electrical degrees, wherein h' is a harmonic being suppressed.
Claim 11
Dependent Claim
41 words
The system according to claim 8, wherein the average angular position of the outer half of said magnetic poles is displaced from the average angular position of the inner half by π/h" electrical degrees, wherein h" is a harmonic being suppressed.
Claim 12
Dependent Claim
115 words
A polyphase electrical stepper motor comprising: a stator including: a plurality of stator pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a rotor with 2N magnetic poles coupled to said stator magnetic circuits through said air gap and being positionable in accordance with the proportioned energization of said phase windings, said plurality of stator pole pieces being divided into a pair of substantially identical symmetrical groupings, the plane of symmetry of one of said groupings being shifted relative to the other by an angle π/hN wherein h is a harmonic being suppressed.
Claim 13
Dependent Claim
115 words
A polyphase electrical stepper motor comprising: a stator including: a plurality of stator pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a rotor with 2N magnetic poles coupled to said stator magnetic circuits through said air gap and being positionable in accordance with the proportioned energization of said phase windings, said plurality of stator pole pieces being divided into a pair of substantially identical symmetrical groupings, the plane of symmetry of one of said groupings being shifted relative to the other by an angle π/hN wherein h is a harmonic being suppressed.
Claim 14
Dependent Claim
27 words
A stepper motor according to claim 11, wherein h is an odd number for suppression of the corresponding harmonic of the torque due to the electric current.
Claim 15
Dependent Claim
20 words
A stepper motor according to claim 11, wherein each of said pole pieces is associated with a separate magnetic circuit.
Claim 16
Dependent Claim
24 words
A stepper motor according to claim 11, wherein a plurality of pole pieces are associated with a common magnetic circuit including two yoke parts,
Claim 17
Dependent Claim
21 words
A stepper motor according to claim 11, wherein said rotor is a thin permanently magnetized disc located in said air gap.
Claim 18
Independent Claim
90 words
A method of making an electric motor to substantially suppress different harmonics comprising the steps of: (1) dividing the motor into a pair of substantially identical, symmetrical groupings, each such grouping being an operative motor combination; (2) axially rotating one grouping of said pair relative to the other by π/h electrical degrees, where h is a harmonic to be suppressed; and (3) repeating steps (1) and (2) for other pairs of groupings to suppress other harmonics, but keeping stationary the axis of symmetry of the pair of groupings previously rotated.
Claim 19
Independent Claim
90 words
A method of making an electric motor to substantially suppress different harmonics comprising the steps of: (1) dividing the motor into a pair of substantially identical, symmetrical groupings, each such grouping being an operative motor combination; (2) axially rotating one grouping of said pair relative to the other by π/h electrical degrees, where h is a harmonic to be suppressed; and (3) repeating steps (1) and (2) for other pairs of groupings to suppress other harmonics, but keeping stationary the axis of symmetry of the pair of groupings previously rotated.
Claim 20
Dependent Claim
38 words
The method according to claim 16, wherein said motor is a two-phase stepper motor including a plurality of pole pieces and wherein said groupings are different pole piece groupings rotated to suppress the 3rd, 4th and 5th harmonics.
Claim 21
Dependent Claim
36 words
The method according to claim 16, wherein said motor is a polyphase stepper motor including a thin permanent magnet disc rotor and wherein one of said pair groupings is a pair grouping of rotor magnetic poles.
Claim 22
Dependent Claim
32 words
The method according to claim 17, wherein the magnetic poles on one side of said disc rotor are axially rotated relative to the magnetic poles on the other side of said disc.
Claim 23
Dependent Claim
28 words
The method according to claim 17, wherein magnetic poles at one radial distance on said disc rotor are axially rotated relative to magnetic poles at another radial distance.
Claim 24
Dependent Claim
17 words
The method according to claim 20, wherein said magnetic poles are skewed to achieve said relative rotation.
Claim 25
Dependent Claim
30 words
The method according to claim 16, wherein said motor is a polyphase stepper motor including a plurality of stator pole pieces and wherein said groupings are different pole piece groupings.
Claim 26
Dependent Claim
15 words
The method according to claim 22, wherein one of said groupings includes alternate pole pieces.
Claim 27
Dependent Claim
17 words
The method according to claim 22, wherein one of said groupings includes alternate pairs of pole pieces.
Claim 28
Dependent Claim
20 words
The method according to claim 22, wherein one of said groupings includes alternate groups of four or more pole pieces.
Claim 29
Dependent Claim
72 words
The method according to claim 21, wherein one of said groupings includes alternate pole pieces with one grouping rotated π/5 electrical degrees relative to the other, another of said groupings includes alternate pairs of pole pieces with one grouping rotated π/3 electrical degrees relative to the other, and another of said groupings includes alternate groups of four or more pole pieces with one grouping rotated π/4 electrical degrees relative to the other.
Claim 30
Dependent Claim
165 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap a rotor with 2N magnetic poles coupled to said stator magnetic circuits through said air gap and being positionable in accordance with the energization of said windings, said plurality of stator pole pieces being divided into at least a first and a second different paired, substantially identical, symmetrical groupings the plane of symmetry of one grouping of said first pair being rotated π/h' electrical degrees relative to the plane of symmetry of the other grouping of the pair to suppress the harmonic h', and the plane of symmetry of one grouping of said second different pair being rotated π/h" electrical degrees relative to the plane of symmetry of the other grouping of said second pair to suppress the harmonic h".
Claim 31
Dependent Claim
165 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap a rotor with 2N magnetic poles coupled to said stator magnetic circuits through said air gap and being positionable in accordance with the energization of said windings, said plurality of stator pole pieces being divided into at least a first and a second different paired, substantially identical, symmetrical groupings the plane of symmetry of one grouping of said first pair being rotated π/h' electrical degrees relative to the plane of symmetry of the other grouping of the pair to suppress the harmonic h', and the plane of symmetry of one grouping of said second different pair being rotated π/h" electrical degrees relative to the plane of symmetry of the other grouping of said second pair to suppress the harmonic h".
Claim 32
Dependent Claim
24 words
A stepper motor according to claim 27, including three paired groupings, said paired groupings being rotated to suppress the 3rd, 4th and 5th harmonics.
Claim 33
Dependent Claim
86 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a thin permanent magnet disc rotor, the magnetic poles on one side of said disc being axially rotated by π/h electrical degrees relative to the magnetic poles on the other side of said disc, where h is a harmonic being suppressed.
Claim 34
Dependent Claim
86 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a thin permanent magnet disc rotor, the magnetic poles on one side of said disc being axially rotated by π/h electrical degrees relative to the magnetic poles on the other side of said disc, where h is a harmonic being suppressed.
Claim 35
Dependent Claim
89 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a thin permanent magnet disc rotor having a plurality of magnetic poles, the magnetic poles at one radial distance of the disc being axially rotated by π/h electrical degrees relative to magnetic poles at another radial distance, where h is a harmonic being suppressed.
Claim 36
Dependent Claim
89 words
A polyphase electrical stepper motor comprising: a stator including a plurality of stator pole pieces, at least two electrical phase windings, stator magnetic circuits for coupling said stator pole pieces to said windings, and said stator pole pieces being disposed to provide an air gap; a thin permanent magnet disc rotor having a plurality of magnetic poles, the magnetic poles at one radial distance of the disc being axially rotated by π/h electrical degrees relative to magnetic poles at another radial distance, where h is a harmonic being suppressed.
Claim 37
Dependent Claim
21 words
The stepper motor according to claim 30, wherein said axial rotation is achieved by skewing said magnetic poles on said disc.
References Cited (Backward Citations)
US4155018A
Cited
US4297625A
Cited
US4330727A
Cited
US4302712A
Cited
US4424463A
Cited
US4518883A
Cited
US4496887A
Cited
US4517478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |