Emerson Electric Company

Other

Dana Emerson Actuator Systems, Llp

Richard E Hartsfield, Jr

Alan D Crapo

Todd A Walls

Kent A Sheeran

Gary E Horst

Paul G Michaels

Mark E Carrier

Daniel E Hilton

Charles P Ketterer

Craig E Wallace

Horst E Gary

Kenneth M De Luca

Jemmi C McDonald

John P Foulsham

Dennis M Hurst

Ken De Luca

Michael E Moore

Mark S East

Power steering motor

An electric power steering system for a vehicle includes a steering wheel and a steering shaft that is connected to the steering wheel. A worm gear is connected to the steering shaft. A worm is threadably engaged to the worm gear. A permanent magnet motor is connected to the worm. The permanent magnet motor includes a stator with twelve slots and a rotor with ten poles. The rotor includes one or more axial rotor sections. If more than one axial rotor section is employed, the axial rotor sections are rotationally offset. The axial rotor sections are rotationally offset by an offset angle that is equal to a cogging angle divided by the number of axial rotor sections. The rotor includes breadloaf, spoke, radial or arc permanent magnets.

Electric power steering system including a permanent magnet motor

A method of determining magnet pole geometry for controlling cogging in an electric motor includes defining the magnet pole geometry in terms of at least one design parameter, predicting cogging as a function of the design parameter, and from the predicted cogging, selecting a value for the design parameter which corresponds to a desired level of cogging in the electric motor.

Controlling electric motor cogging

An interior permanent magnet machine including a rotor stack defining at least two adjacent magnet retention slots and a plurality of permanent magnets positioned within the interior of the rotor, wherein the radial thickness of the rotor that is above a given magnet retention slot transitions from a first radial thickness to a bridge region having a second radial thickness that is less than the first radial thickness. The bridge region is positioned between the two magnet retention slots and the transition to the bridge region occurs within an area falling within a defined angular expanse. Areas of low permeability are positioned below the bridge region between the ends of the adjacent permanent magnets such that (i) there are no direct linear paths between the end edges of the two adjacent magnets that do not pass through an area of low permeability, and (ii) that there are no direct linear paths that extend radially from the outer portion of the rotor to the interior of the rotor, between the permanent magnets, that do not also pass through an area of low permeability.

Permanent magnet machine

A method of connecting phases of a segmented stator electric machine includes providing a stator core. An end cap assembly is attached to the stator core. Winding wire is wound around the end cap assembly and the stator core to form a stator segment assembly. A plurality of the stator segment assemblies are assembled into a stator including first, second and third phases. A phase wire stitching machine is used to connect opposite ends of the winding wire of each of the stator segment assemblies to form the first, second and third phases of the stator. The phase wires can be attached to the stator segment assemblies using terminals, IDCs, hook terminals, and/or directly to the winding wire.

Interconnecting method for segmented stator electric machines

An interconnecting ring and wire guide for an electric machine includes an annular radial ring having a radially inner edge and a radially outer edge. An axial ring projects axially from the radially inner edge of the annular radial ring. A guide positioner positions the annular radial ring and the axial ring relative to the electric machine. Wire dividers are located on a radially outer surface of the radial ring. The wire dividers include a plurality of circumferential projections that are formed on the radially outer surface of the radial ring. A plurality of wire guides are located adjacent to a radially outer edge of the annular radial ring. Indicia on an outer surface of the annular radial ring identifies at least one of a mounting position for the interconnecting ring and wire guide and a wiring schematic for phases wiring of the electric machine.

Interconnecting ring and wire guide

A method of determining magnet pole geometry for controlling cogging in an electric motor includes defining the magnet pole geometry in terms of at least one design parameter, predicting cogging as a function of the design parameter, and from the predicted cogging, selecting a value for the design parameter which corresponds to desired level of cogging in the electric motor.

A permanent magnet electric machine with reduced cogging torque includes a plurality of axial rotor sections that are defined on a radially outer surface of a rotor. The axial rotor sections include a set of permanent magnets that are in an unmagnetized state and that have opposite edges that are aligned with an axis of the rotor. The axial rotor sections are rotationally offset such that the edges of the permanent magnets create stair step interfaces. The n sets of permanent magnets are magnetized using a magnetizing fixture. The permanent magnets have a generally rectangular shape and are preferably arc magnets or breadloaf magnets. The conductors of the magnetizing fixture are aligned with the stair step interfaces. A magnetic field induced in the permanent magnets is substantially reduced along the stair step interfaces.

Reduced cogging torque permanent magnet electric machine with rotor having offset sections

The construction of an electromagnetic device, such as an electric motor, has a segmented stator with a plurality of stator teeth held in a circular pattern solely by a shell of the motor that has been hot dropped over the stator teeth.

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Chesterfield, MO, United States of America

Richard E Hartsfield, Jr