US6498451B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Torque ripple free electric power steering
Assignee: GM Global Technology Operations LLC
•
Filing: 2000-09-06
•
Granted: 2002-12-24
•
Expires: 2020-09-06
Abstract
Abstract Disclosed is an electric motor system with reduced torque ripple comprising a sinusoidally magnetized permanent magnet, a sinusoidal inverter, a higher resolution position sensor, a composite iron stator yoke, a composite reinforced plastic rotor core and shaft; and a high gear ratio gear reduction box. The novel combination of magnet, inverter, sensor, plastic rotor core and shaft and high gear ratio gear box substantially reduces the torque ripple on the shaft of said motor system.
Inventors
- 👤 Nady Boules
- 👤 Rassem Ragheb Henry
- 👤 Chandra Sekhar Namuduri
- 👤 Thomas Wolfgang Nehl
- 👤 Bruno Patrice Bernard
- 👤 Shaotang Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:42
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0403; H; H02; H02K; H02K29/00; H02K29/03; H02K29/06; H02K29/08; H02P; H02P6/00; H02P6/10; H02K7/00; H02K7/10; H02K7/116; H02P2209/00; H02P2209/07
Claims Analysis
Total Claims: 77
Claim 1
Independent Claim
106 words
An electric motor system with reduced torque ripple comprising: an electric motor having a stator and a rotor and at least one windings; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one winding current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding currents to be essentially sinusoidal.
Claim 2
Dependent Claim
106 words
An electric motor system with reduced torque ripple comprising: an electric motor having a stator and a rotor and at least one windings; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one winding current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding currents to be essentially sinusoidal.
Claim 3
Dependent Claim
19 words
The invention of claim 1 wherein said permanent magnetic means further comprises at least one sinusoidally magnetized permanent magnets.
Claim 4
Dependent Claim
14 words
The invention of claim 1 wherein said electric motor further comprises slotless airgap windings.
Claim 5
Dependent Claim
22 words
The invention of claim 1 wherein said at least one windings of said electric motor are located in slots separated by teeth.
Claim 6
Dependent Claim
15 words
The invention of claim 1 wherein said stator is made from a powdered iron composite.
Claim 7
Dependent Claim
13 words
The invention of claim 5 wherein said stator is also the motor housing.
Claim 8
Dependent Claim
15 words
The invention of claim 1 wherein said rotor further comprises a composite reinforced plastic shaft.
Claim 9
Dependent Claim
14 words
The invention of claim 1 wherein said rotor further comprises a composite iron shaft.
Claim 10
Dependent Claim
39 words
The invention of claim 1 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a current-mode control.
Claim 11
Dependent Claim
39 words
The invention of claim 1 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a voltage-mode control.
Claim 12
Dependent Claim
25 words
The invention of claim 1 wherein said higher-resolution position sensor further comprises: an incremental position sensor; and an absolute position sensor defining a reference angle.
Claim 13
Dependent Claim
86 words
The invention of claim 11 wherein said absolute position sensor further defines one or more electronic signal, where said one or more electronic signal each includes a first level and a second level, and said reference angle is based upon a transition from said first level to said second level of one said electronic signal when said motor is rotating clockwise, and is based upon a transition from said second level to said first level of said one electronic signal when said motor is rotating counterclockwise.
Claim 14
Dependent Claim
90 words
The invention of claim 12 wherein a power-up phase of said electric motor further includes the steps of: determining an angular interval from said one or more electronic signals from said absolute position sensor; exciting one or more said winding from said motor according to said determined angular interval; and, controlling said winding currents to be essentially sinusoidal after one of said electronic signals from said absolute position sensor has effected a transition from one of said first and second levels to the other of said first and second levels.
Claim 15
Dependent Claim
38 words
The invention of claim 11 wherein said at least one motor windings of said electric motor is arranged into one or more phases, and said absolute position sensor further comprises one electronic signal for each said motor phase.
Claim 16
Dependent Claim
71 words
The invention of claim 1 wherein said higher-resolution position sensor comprises: a magnetoresistor; a toothed track; and said magnetoresistor(s) and toothed track(s) mounted in said motor such that relative rotational motion between said rotor and said stator results in relative rotational motion between said magnetoresistor(s) and said toothed track(s); and wherein said magnetoresistor(s) is disposed sufficiently close to said toothed tracks(s) so as to be effective in detecting said relative motion.
Claim 17
Dependent Claim
15 words
The invention of claim 2 wherein said electric motor further comprises slotless air gap windings.
Claim 18
Dependent Claim
22 words
The invention of claim 16 wherein said at least one winding of said electric motor are located in slots separated by teeth.
Claim 19
Dependent Claim
15 words
The invention of claim 17 wherein said stator is made from a powdered iron composite.
Claim 20
Dependent Claim
13 words
The invention of claim 18 wherein said stator is also the motor housing.
Claim 21
Dependent Claim
15 words
The invention of claim 19 wherein said rotor further comprises a composite reinforced plastic shaft.
Claim 22
Dependent Claim
14 words
The invention of claim 19 wherein said rotor further comprises a composite iron shaft.
Claim 23
Dependent Claim
39 words
The invention of claim 21 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding current is responsive to said torque command, and wherein said control is a current-mode control.
Claim 24
Dependent Claim
39 words
The invention of claim 21 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding current is responsive to said torque command, and wherein said control is a voltage-mode control.
Claim 25
Dependent Claim
25 words
The invention of claim 22 wherein said higher-resolution position sensor further comprises: an incremental position sensor; and an absolute position sensor defining a reference angle.
Claim 26
Dependent Claim
86 words
The invention of claim 24 wherein said absolute position sensor further defines one or more electronic signal, where said one or more electronic signal each includes a first level and a second level, and said reference angle is based upon a transition from said first level to said second level of one said electronic signal when said motor is rotating clockwise, and is based upon a transition from said second level to said first level of said one electronic signal when said motor is rotating counterclockwise.
Claim 27
Dependent Claim
90 words
The invention of claim 25 wherein a power-up phase of said electric motor further includes the steps of: determining an angular interval from said one or more electronic signals from said absolute position sensor; exciting one or more said winding from said motor according to said determined angular interval; and, controlling said winding currents to be essentially sinusoidal after one of said electronic signals from said absolute position sensor has effected a transition from one of said first and second levels to the other of said first and second levels.
Claim 28
Dependent Claim
38 words
The invention of claim 24 wherein said at least one motor windings of said electric motor is arranged into one or more phases, and said absolute position sensor further comprises one electronic signal for each said motor phase.
Claim 29
Dependent Claim
71 words
The invention of claim 27 wherein said higher-resolution position sensor comprises: a magnetoresistor; a toothed track; and said magnetoresistor(s) and toothed track(s) mounted in said motor such that relative rotational motion between said rotor and said stator results in relative rotational motion between said magnetoresistor(s) and said toothed track(s); and wherein said magnetoresistor(s) is disposed sufficiently close to said toothed tracks(s) so as to be effective in detecting said relative motion.
Claim 30
Dependent Claim
113 words
An electric motor system with reduced torque ripple for power assisted steering in a motor vehicle comprising: an electric motor having a stator and a rotor and at least one windings; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding current to be essentially sinusoidal.
Claim 31
Dependent Claim
113 words
An electric motor system with reduced torque ripple for power assisted steering in a motor vehicle comprising: an electric motor having a stator and a rotor and at least one windings; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding current to be essentially sinusoidal.
Claim 32
Dependent Claim
19 words
The invention of claim 29 wherein said permanent magnetic means further comprises at least one sinusoidally magnetized permanent magnets.
Claim 33
Dependent Claim
14 words
The invention of claim 29 wherein said electric motor further comprises slotless airgap windings.
Claim 34
Dependent Claim
22 words
The invention of claim 29 wherein said at least one windings of said electric motor are located in slots separated by teeth.
Claim 35
Dependent Claim
15 words
The invention of claim 29 wherein said stator is made from a powdered iron composite.
Claim 36
Dependent Claim
13 words
The invention of claim 33 wherein said stator is also the motor housing.
Claim 37
Dependent Claim
15 words
The invention of claim 29 wherein said rotor further comprises a composite reinforced plastic shaft.
Claim 38
Dependent Claim
14 words
The invention of claim 29 wherein said rotor further comprises a composite iron shaft.
Claim 39
Dependent Claim
39 words
The invention of claim 29 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a current-mode control.
Claim 40
Dependent Claim
39 words
The invention of claim 29 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a voltage-mode control.
Claim 41
Dependent Claim
25 words
The invention of claim 29 wherein said higher-resolution position sensor further comprises: an incremental position sensor; and an absolute position sensor defining a reference angle.
Claim 42
Dependent Claim
86 words
The invention of claim 39 wherein said absolute position sensor further defines one or more electronic signal, where said one or more electronic signal each includes a first level and a second level, and said reference angle is based upon a transition from said first level to said second level of one said electronic signal when said motor is rotating clockwise, and is based upon a transition from said second level to said first level of said one electronic signal when said motor is rotating counterclockwise.
Claim 43
Dependent Claim
90 words
The invention of claim 40 wherein a power-up phase of said electric motor further includes the steps of: determining an angular interval from said one or more electronic signals from said absolute position sensor; exciting one or more said winding from said motor according to said determined angular interval; and, controlling said winding currents to be essentially sinusoidal after one of said electronic signals from said absolute position sensor has effected a transition from one of said first and second levels to the other of said first and second levels.
Claim 44
Dependent Claim
38 words
The invention of claim 39 wherein said at least one motor windings of said electric motor is arranged into one or more phases, and said absolute position sensor further comprises one electronic signal for each said motor phase.
Claim 45
Dependent Claim
71 words
The invention of claim 29 wherein said higher-resolution position sensor comprises: a magnetoresistor; a toothed track; and said magnetoresistor(s) and toothed track(s) mounted in said motor such that relative rotational motion between said rotor and said stator results in relative rotational motion between said magnetoresistor(s) and said toothed track(s); and wherein said magnetoresistor(s) is disposed sufficiently close to said toothed tracks(s) so as to be effective in detecting said relative motion.
Claim 46
Dependent Claim
24 words
The invention of claim 29 wherein said electric motor system with reduced torque ripple is mounted on the steering column of said motor vehicle.
Claim 47
Dependent Claim
15 words
The invention of claim 30 wherein said electric motor further comprises slotless air gap windings.
Claim 48
Dependent Claim
22 words
The invention of claim 45 wherein said at least one winding of said electric motor are located in slots separated by teeth.
Claim 49
Dependent Claim
15 words
The invention of claim 46 wherein said stator is made from a powdered iron composite.
Claim 50
Dependent Claim
13 words
The invention of claim 47 wherein said stator is also the motor housing.
Claim 51
Dependent Claim
15 words
The invention of claim 48 wherein said rotor further comprises a composite reinforced plastic shaft.
Claim 52
Dependent Claim
14 words
The invention of claim 48 wherein said rotor further comprises a composite iron shaft.
Claim 53
Dependent Claim
39 words
The invention of claim 49 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding current is responsive to said torque command, and wherein said control is a current-mode control.
Claim 54
Dependent Claim
39 words
The invention of claim 49 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding current is responsive to said torque command, and wherein said control is a voltage-mode control.
Claim 55
Dependent Claim
25 words
The invention of claim 51 wherein said higher-resolution position sensor further comprises: an incremental position sensor; and an absolute position sensor defining a reference angle.
Claim 56
Dependent Claim
86 words
The invention of claim 53 wherein said absolute position sensor further defines one or more electronic signal, where said one or more electronic signal each includes a first level and a second level, and said reference angle is based upon a transition from said first level to said second level of one said electronic signal when said motor is rotating clockwise, and is based upon a transition from said second level to said first level of said one electronic signal when said motor is rotating counterclockwise.
Claim 57
Dependent Claim
90 words
The invention of claim 54 wherein a power-up phase of said electric motor further includes the steps of: determining an angular interval from said one or more electronic signals from said absolute position sensor; exciting one or more said winding from said motor according to said determined angular interval; and, controlling said winding currents to be essentially sinusoidal after one of said electronic signals from said absolute position sensor has effected a transition from one of said first and second levels to the other of said first and second levels.
Claim 58
Dependent Claim
38 words
The invention of claim 55 wherein said at least one motor windings of said electric motor is arranged into one or more phases, and said absolute position sensor further comprises one electronic signal for each said motor phase.
Claim 59
Dependent Claim
71 words
The invention of claim 56 wherein said higher-resolution position sensor comprises: a magnetoresistor; a toothed track; and said magnetoresistor(s) and toothed track(s) mounted in said motor such that relative rotational motion between said rotor and said stator results in relative rotational motion between said magnetoresistor(s) and said toothed track(s); and wherein said magnetoresistor(s) is disposed sufficiently close to said toothed tracks(s) so as to be effective in detecting said relative motion.
Claim 60
Dependent Claim
24 words
The invention of claim 57 wherein said electric motor system with reduced torque ripple is mounted on the steering column of said motor vehicle.
Claim 61
Dependent Claim
162 words
A electric power assisted steering system for a motor vehicle including an electric motor system, the steering system comprising: a steerable wheel coupled to a movable rack-pinion gear assembly; a reduced torque ripple electric motor having a stator and a rotor and at least one windings coupled to said movable rack and a steering wheel; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding current to be essentially sinusoidal; wherein said motor applies an assist torque to said rack-pinion assembly responsive to a command, said command responsive to torque applied to said steering wheel.
Claim 62
Dependent Claim
162 words
A electric power assisted steering system for a motor vehicle including an electric motor system, the steering system comprising: a steerable wheel coupled to a movable rack-pinion gear assembly; a reduced torque ripple electric motor having a stator and a rotor and at least one windings coupled to said movable rack and a steering wheel; said electric motor comprising: permanent magnetic means effective in generating an essentially sinusoidal magnetic field; and a higher-resolution position sensor effective in sensing the angular position of said rotor; and a sinusoidal inverter coupled to said electric motor to drive at least one current through said at least one windings of said electric motor wherein said sinusoidal inverter is adapted to receive angular position information from said higher-resolution position sensor to control said at least one winding current to be essentially sinusoidal; wherein said motor applies an assist torque to said rack-pinion assembly responsive to a command, said command responsive to torque applied to said steering wheel.
Claim 63
Dependent Claim
22 words
The steering system of claim 59 wherein said permanent magnetic means further comprises at least one or more sinusoidally magnetized permanent magnets.
Claim 64
Dependent Claim
15 words
The steering system of claim 60 wherein said electric motor further comprises slotless airgap windings.
Claim 65
Dependent Claim
23 words
The steering system of claim 59 wherein said at least one windings of said electric motor are located in slots separated by teeth.
Claim 66
Dependent Claim
16 words
The steering system of claim 59 wherein said stator is made from a powdered iron composite.
Claim 67
Dependent Claim
14 words
The steering system of claim 63 wherein said stator is also the motor housing.
Claim 68
Dependent Claim
16 words
The steering system of claim 59 wherein said rotor further comprises a composite reinforced plastic shaft.
Claim 69
Dependent Claim
15 words
The steering system of claim 59 wherein said rotor further comprises a composite iron shaft.
Claim 70
Dependent Claim
40 words
The steering system of claim 59 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a current-mode control.
Claim 71
Dependent Claim
40 words
The steering system of claim 59 wherein said electric motor system further comprises a torque command, wherein said control of said at least one winding currents is responsive to said torque command, and wherein said control is a voltage-mode control.
Claim 72
Dependent Claim
26 words
The steering system of claim 59 wherein said higher-resolution position sensor further comprises: an incremental position sensor; and an absolute position sensor defining a reference angle.
Claim 73
Dependent Claim
87 words
The steering system of claim 69 wherein said absolute position sensor further defines one or more electronic signal, where said one or more electronic signal each includes a first level and a second level, and said reference angle is based upon a transition from said first level to said second level of one said electronic signal when said motor is rotating clockwise, and is based upon a transition from said second level to said first level of said one electronic signal when said motor is rotating counterclockwise.
Claim 74
Dependent Claim
91 words
The steering system of claim 70 wherein a power-up phase of said electric motor further includes the steps of: determining an angular interval from said one or more electronic signals from said absolute position sensor; exciting one or more said winding from said motor according to said determined angular interval; and, controlling said winding currents to be essentially sinusoidal after one of said electronic signals from said absolute position sensor has effected a transition from one of said first and second levels to the other of said first and second levels.
Claim 75
Dependent Claim
39 words
The steering system of claim 69 wherein said at least one motor windings of said electric motor is arranged into one or more phases, and said absolute position sensor further comprises one electronic signal for each said motor phase.
Claim 76
Dependent Claim
72 words
The steering system of claim 59 wherein said higher-resolution position sensor comprises: a magnetoresistor; a toothed track; and said magnetoresistor(s) and toothed track(s) mounted in said motor such that relative rotational motion between said rotor and said stator results in relative rotational motion between said magnetoresistor(s) and said toothed track(s); and wherein said magnetoresistor(s) is disposed sufficiently close to said toothed tracks(s) so as to be effective in detecting said relative motion.
Claim 77
Dependent Claim
21 words
The steering system of claim 59 wherein said electric motor system is mounted on the steering column of said motor vehicle.
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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) | 2005-12-23 | 2006-06-24 | 2006-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-23 | 2010-06-24 | 2010-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-23 | 2014-06-24 | 2014-12-24 | $7700.00 | Window Closed / Lapsed |