Switched Reluctance Drives Limited

Emerson Electric Company

Nidec Motor Corporation

Nidec Sr Drives, Ltd

Steven Paul Randall

Donald J Williams

Andrew F Poag

Thomas E Kirkley, Jr

C Theodore Peachee

Lawrence J Wittman

Michael Leo McClelland

Geoffrey Thomas Brown

James A Wafer

Richard S Wallace, Jr

Marielle Piron

David M Sudgen

Joseph Gerald Marcinkiewicz

Mark John Cherney

James L Skinner

Raymond D Heilman

Ronald W Schmidt

Kenneth R Friedman

Craig E Wallace

Gregory R Maes

Willliam Vail

William Vail

An electric motor assembly including a stator having a stator core and windings around the stator core is disclosed. The stator core has opposing ends and an outer surface extending between the opposing ends. The electric motor assembly also includes a housing having an inner surface enclosing at least a portion of the stator, and at least one fluid passage between the outer surface of the stator core and the inner surface of the housing. The fluid passage permits a coolant in the fluid passage to contact one or more portions of the outer surface of the stator core to remove heat from the stator core during operation of the electric motor assembly. Additional motor assemblies including stator and/or rotor cooling features are disclosed.

Electric motor assemblies including stator and/or rotor cooling

An electric motor is provided. A rotor sensor mechanism is operable to sense a condition of the rotor. The rotor sensor mechanism includes a target component, a radial sensor, and a sensor carrier. The target component comprises a shutter wheel fixed relative to the rotor for rotational movement therewith. The shutter wheel includes a plurality of circumferentially spaced, radially projecting radial target teeth. The radial sensor is configured to sense the target teeth. The radial sensor is at least generally axially aligned with the radial target teeth and faces radially toward the radial target teeth. The sensor carrier adjustably supports the radial sensor on the motor frame assembly so as to permit the radial sensor to be selectively positioned relative to the radial target teeth.

Internal rotor sensor having adjustable sensor carrier

A brushless electrical machine has at least one phase winding which produces torque to drive a load. The control system for the machine is able to vary the flux and current supplied to a phase so as to vary the torque output as a function of the rotor position. The energization is reduced at particular angles to produce a dip in the torque profile, thus ensuring that, if the drive stalls, it does so at a predetermined position, for example where the losses in the drive are minimized.

Control of a brushless electrical machine

The windings of a switched reluctance machine are supplied from a converter which is capable of providing bipolar energization. The energization pattern supplied to the windings is dependent on the number of stator and rotor poles in the machine and is selected to produce unipolar energization in the rotor poles. This in turn reduces the losses in the rotor which would otherwise result from bipolar energization. The machine may also be operated to provide energization patterns which are adapted to provide optimum performance in different parts of its operating speed range.

Control of a switched reluctance machine

A switched reluctance machine has salient poles on the stator and rotor. The windings of the machine are supplied from a converter which provides energization at a chosen rate. The windings of the machine may be energized at the rate at which the rotor poles pass the stator poles, or it may be operated at a fraction of that rate by energizing the windings to cooperate with every second, third or fourth rotor pole. This can extend the output of the machine.

Control of an electrical machine

A variable reluctance generator has phase windings and a bias winding. By controlling the excitation produced by the bias winding, the speed of the machine or the DC link, a power converter using only diodes can supply power to a DC bus. A method of operating a variable reluctance machine as a generator, the machine having at least one phase winding, includes creating a bias flux linking the or at least one phase winding, and limiting the phase voltage to a magnitude below that otherwise induced in the phase winding by the bias flux.

Variable reluctance generator

An electro-mechanical transmission system, driven by a prime mover, includes two epicyclic gearsets connected between input and output shafts, and two electrical machines having their rotors connected to respective elements of the two gearsets. The torque on the output shaft is boosted by a controller, which dumps energy from the system when one of the machines is acting as a generator and the other as a motor.

Electro-mechanical transmission systems

A switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to maximize the inductance of an energized winding. A drive circuit energizes the winding wire around the stator segment assemblies based on a rotational position of the rotor. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.

Segmented stator switched reluctance machine

A sensorless switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to a rotational position that maximizes the inductance of an energized winding. A sensorless drive circuit derives rotor position and energizes the winding wire around the stator segment assemblies based on the derived rotor position. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.

Sensorless switched reluctance electric machine with segmented stator

A cooling system for an electrical machine includes at least one set of heat-conducting inserts positioned so as to transmit heat from at least one part of the winding in the stator to a heatsink. The heatsink may be the frame of the machine itself, but could also be a coolant pipe mounted at one or both ends of the stator. One form of insert is arranged between windings to draw heat away from the sides of the poles. Another form of insert is arranged on the ends of the poles to draw heat from that region.

Cooling of electrical machines

A fan assembly includes a fan housing and a fan. A switched reluctance fan motor is mounted in an inlet of the fan housing and includes a shaft that is connected to the fan. The switched reluctance fan motor includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include a stator segment core. Winding wire is wound around the stator segment core. A rotor tends to rotate relative to the stator to a rotational position that maximizes the inductance of an energized winding. A drive circuit energizes the winding wire around the stator segment assemblies based on the rotational position of the rotor. End cap assemblies are connected to opposite axial ends of the stator segment core. The end cap assemblies define an annular channel for receiving the winding wire and for preventing winding creep.

Fan assembly including a segmented stator switched reluctance fan motor

A washing machine includes a tub that is rotated by a switched reluctance motor. The tub includes an outer tub and an inner tub. The drive is a direct drive or a drive assembly that includes a shaft, a belt and a spinner pulley connected to the tub. The switched reluctance motor includes a stator with a plurality of circumferentially-spaced stator segment assemblies. Winding wire is wound around a stator segment core of the stator segment assemblies. A rotor is connected to the shaft that drives the belt and rotates the spinner pulley. A drive circuit energizes the winding wire around the stator segment assemblies based on a rotational position of the rotor. End cap assemblies are connected to opposite axial ends of the stator segment core. The end cap assemblies define an annular channel for receiving the winding wire and for preventing winding creep.

Washing machine including a segmented stator switched reluctance motor

A novel coil shape, particularly suitable for 1-phase switched reluctance machines, is disclosed. The coil may be wound on a bobbin which is then inserted into the stator or it may be free standing. The shape is such that it can be inserted into the stator without further deformation of its shape to allow subsequent components of the machine to be assembled.

Growing community of inventors

Leeds, United Kingdom

Steven Paul Randall