General Electric Company

Eike Richter

Gerald Burt Kliman

James Patrick Lyons

Mark A Preston

John Andrew Mallick

Donald W Jones

Arthur Vorwerk Radun

Fred W Staub

Henry G Lenz

Kiyoung Chung

George M Rosenberry, Jr

Timothy J Miller

Albert Frank Storace

Gary L Kalan

Thomas A Nondahl

Edward A Fisher

George Edward Brissey

A stator coil winding arrangement comprises an inner layer and an outer layer, which define the two layers of the coil. A first turn of the inner layer is positioned directly over the outer layer. All subsequent turns of the inner layer return to the inner layer to be positioned over the inner layer. With this winding arrangement, total losses in the stator coil are reduced by approximately a factor of two.

Winding arrangement for switched reluctance machine based internal starter generator

A magnetic thrust compensator for a mechanical thrust bearing includes a parallel operating axial magnetic bearing including a stator including two parallel stator extensions, a rotor disk situated between the two stator extensions, and first and second electromagnets each situated on a respective stator extension and facing the rotor disk. A controller selectively energizes one of the electromagnets. Additional stator extensions and rotor disks can be used to provide fault tolerance. The electromagnets can each include dual annular windings. The compensator can include an additional stator extension, an additional rotor disk, and bias magnet situated on the additional stator extension and facing the additional rotor disk with the controller being adapted to selectively supply current to the bias magnet. In a closed loop embodiment, the mechanical thrust bearing can be spring mounted and, to determine the appropriate energization level of one of the electromagnets, the controller can determine a magnetic air gap length between the rotor disk and one of the stator extensions.

Current-controlled magnetic thrust compensators for mechanical thrust

The invention comprises a switched reluctance machine including a stator and a rotor wherein the stator includes stator teeth wound with separately excitable phase windings. The separately excitable phase windings receiving a combination of signals wherein the first of those signals is a phase winding signal and the second of those signals is a magnetic bearing signal. A method of controlling a switched reluctance machine wherein the switched reluctance machine includes separately excitable stator windings. The method comprising the steps of exciting each stator winding with a signal representative of the phase excitation for that winding and superimposing on each of said windings a signal capable of producing the magnetic force necessary to support the rotor in the absence of a mechanical bearing.

Integrated magnetic bearing/switched reluctance machine

A permanent magnet rotor is shaped to optimize the flux distribution thereabout. In one embodiment, cut-outs in the rotor core between magnetic poles forces more of the magnetizing flux, i.e., that which would normally be distributed about the transition zone between the poles, into the main part of the poles, resulting in a substantially trapezoidal flux distribution that is substantially flat over approximately the central 120.degree. of each respective 180.degree. half-cycle thereof. In an alternative embodiment, the rotor core is shaped to be substantially square with rounded edges. Permanent magnet material is molded onto the square-shaped rotor core to form a plurality of magnetic poles such that the flux distribution about the rotor core is substantially sinusoidal.

Modable permanent magnet rotor for optimized field shaping

A switched reluctance machine comprising a housing, a stator attached to the housing and a rotor mounted within the housing. The stator including teeth wound with electrical coils which are connected to form phase windings. The rotor comprising a series of laminates including teeth pressed onto a shaft. According to the present invention, at least one set of opposing phase wound stator teeth comprise permanent magnets.

Switched reluctance machine including permanent magnet stator poles

The invention comprises a motor including a stator having stator teeth. The motor further includes a rotor having rotor teeth wherein the rotor is mounted on a shaft which is supported by a bearing. According to the present invention, the rotor is conically shaped such that the gap between the rotor and stator increases in proportion to the distance from the bearing.

Conical rotor for switched reluctance machine

An dynamoelectric machine is provided having a hollow shaft adapted to receive fluid at one end and to discharge it at the other. The hollow shaft has a stack of laminations mounted thereon. A hollow disk is situated adjacent to and in contact with an axial end of the stack of laminations. The hollow disk includes a generally circular baffle for dividing the hollow disk into two interior sections and to cause the fluid to rotate at the same angular velocity as the hollow disk. The two interior sections are in flow communication with one another of the periphery at the generally circular baffle. The hollow shaft is in flow communication with one of the sections for providing fluid and in flow communication with the other section for removing fluid. A stator surrounds the laminations and is spaced away therefrom.

Motor cooling using a liquid cooled rotor

An improved reluctance motor with reduced windage losses and reduced internal rotor stresses is proposed. The reluctance motor is constructed with continuous, non-magnetic supported members in the interpolar spaces of the salient pole rotor. End plates may be added to the rotor which are attached to the support members creating a 'cage' structure which supports the rotor. In addition, the rotor through shaft may be eliminated by providing stub shafts on the cage end plates to transmit torque from the rotor. Various methods of constructing the rotor of the invention are also described.

Construction of reluctance motors

Electromagnetic damping techniques for use in slowing down the shaft to a gas turbine based on various electrical machine concepts. A rotor may be mounted on an outer race of a bearing through which the shaft extends. The damper may use a permanent magnet (PM) design with permanent magnets mounted to the rotor. Alternately, the rotor and stator may be designed to operate upon a switched reluctance motor (SRM) design. Instead of having the rotor mounted to the outer race, an alternate arrangement may use a rotor mounted directly to the gas turbine shaft in which case the rotor and a corresponding stator serve both as a damper and as an electrical generator for providing the usual electrical generation functions from the gas turbine shaft.

Electromagnetic damping of a shaft

A permanent magnet rotor uses a magnetic shaft having a rhomboidal cross section. Fastening means secure clamp pieces which in turn retain pole pieces and the permanent magnets.

Multi-section permanent magnet rotor

A magnetic wedge for use in toothed stators holds the stator windings in the slots formed between the teeth of the stator. The magnetic slot wedge comprises a nonmagnetic body, with a width corresponding to the width of the slot. The nonmagnetic body has parallel laminations of magnetic material extending part way through the width of the magnetic body from both sides of the magnetic body and perpendicular to the top surface. A central nonmagnetic region is thereby created with a region on either side of the central portion having an average permeability, along its length, substantially in the range of about 5-10.

Magnetic slot wedge with low average permeability and high mechanical

A magnetic wedge for use in toothed stators holds the stator windings in the slots formed between the teeth of the stator. The magnetic slot wedge comprises a stack of magnetic material with a width corresponding to the width of the slot. The laminations each have central bridge portions connecting a first and second magnetic region, the bridge portion saturating during machine operation. The bridge and the first and second magnetic regions define an opening which, when the laminations are stacked, form a channel having a narrowed entrance. A fiberglass rod fits inside the channel and provides axial stiffness to the stacked laminations which clamp on the fiberglass rod.

A homopolar inductor-alternator machine is constructed to have lower transient rectances by the incorporation of a current conducting ring concentric with the axis of the rotor and positioned on the rotor and/or the stator. The conducting ring helps prevent time varying fluxes from inducing eddy current flow in the high permeability rotor steel and unlaminated stator flux return path (back iron). The conducting ring acts upon the transient fluxes which occur in the DC flux path of the machine.

Flux shield for an inductor-alternator machine

Output regulation of a permanent magnet excited disk-type synchronous machine having permanent magnets attached to rotor disks in multipolar configuration is achieved by controlled alignment of stator windings. Rotor disks support permanent magnets oriented to direct flux axially through the machine, and multiple stator disks having distributed multi-phase windings have means to rotate one of the stator disks to cause misalignment of windings on adjacent disks having the same phase. By controlling the degree of phase misalignment, output voltage of a generator or power factor of a motor may be controlled.

Method and apparatus for output regulation of multiple disk permanent

A two-pole permanent magnet A.C. machine employs one set of permanent magnets disposed with their magnetic axes parallel to the axis of rotation of the rotor and a second set of permanent magnets disposed so that their magnetic axes are oriented radially. This arrangement allows for significant reduction in flux leakage from the machine rotor and an increase in the power density of the machine.

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Cincinnati, OH, United States of America

Eike Richter