Torque ripple free electric power steering
AssigneeDelphi Technologies, Inc.
InventorsNady Boules, Rassem Ragheb Henry, Chandra Sekhar Namuduri, Thomas Wolfgang Nehl, Bruno Patrice Bernard, Shaotang Chen
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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.
Claims74
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.
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.
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.
Dependencies are inferred from the claim text.