The invention relates to an electric machine comprising a stator and a rotor moveable relative to the stator. The stator has slots for accommodating electrical windings, wherein teeth of the stator are formed between adjacent slots. During operation of the machine, an operating wave of the magnetomotive force is different from a fundamental wave of the magnetic flux. The stator comprises at least one recess which is arranged in the tooth region and extends substantially in the radial direction.

A switched reluctance machine has a stator core salient with stator poles disposed concentrically with a rotor that is salient with rotor poles. A plurality of coil windings are wound about the stator core so that a pair of windings are adjacent each of the stator poles. The pair of coil windings induces magnetic flux in the adjacent stator poles and the rotor rotates to align the rotor poles with the stator poles having the induced magnetic flux. The rotor is rotatable at high speeds of up to 50,000 RPM and the coil windings can be directly cooled.

A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least two stators having a plurality of stator poles. The at least two rotors and the at least two stators are positioned about a central axis with the stator placed between the rotors. In other embodiments, the number of stators equals the number of rotors and effectively operate as a single stator and rotor. In yet another embodiment, the effective single stator and rotor type high rotor pole switched reluctance machine is realized as single stator and rotor positioned concentrically around a central axis.

A synchronous reluctance motor assisted by permanent magnets comprises a stator provided with stator windings, for generating a magnetic flux, which has a circular central seat to house a cylindrical shaped rotor suitable for being actuated in rotation about an axis of rotation, wherein the rotor comprises internal slots, for housing respective permanent magnets, and wherein the internal slots and the permanent magnets are curvilinear shaped in order to optimise the magnetic interaction between the rotor and the stator windings.

An electromagnetic rotary drive includes a contactlessly magnetically drivable rotor that is coil-free and free of permanent magnets and that includes a magnetically effective core, and a stator by which the rotor is contactlessly magnetically drivable about a desired axis of rotation in the operating state. The stator has a plurality of coil cores of which each includes a bar-shaped longitudinal limb extending from a first end in a direction in parallel with the desired axis of rotation up to a second end, all the first ends being connected by a reflux of windings generate an electromagnetic rotational field of which each surrounds one of the longitudinal limbs. The coil cores include a plurality of permanent magnets by which a permanent magnetic pre-magnetization flux can be generated.

A simple rugged motor has a stator and a rotor formed by stacked silicon steel sheets operates by having a plurality of major and minor coil windings of the stator individually electrified under signals of a control unit, so as to steadily drive a rotor thereof. The simple rugged motor further has an orbit coupling balance assembly engaging an orbiting scroll for a corresponding fixed scroll disposed in a compression chamber to orbit for air compression, so as to form a scroll compressor. Or the simple rugged motor has a coupling assembly engaging a female screw compressor rotor to compress the air by a rotatable male screw compressor rotor disposed in a compression chamber, so as to form a screw compressor.

The present embodiment is a high rotor pole switched reluctance machine (HRSRM) which provides a plurality of combinations of the number of rotor poles R.sub.n and number of stator poles S.sub.n utilizing a numerical relationship defined by a mathematical formula, R.sub.n=2S.sub.nF.sub.p, when S.sub.n=mF.sub.p, wherein F.sub.p is the maximum number of independent flux paths in the stator when stator and rotor poles are fully aligned, and m is the number of phases. The mathematical formulation provides an improved noise performance and design flexibility to the machine. The mathematical formulation further provides a specific number of stator and rotor poles for a chosen m and Fp. The HRSRM can be designed with varying number of phases. The HRSRM provides a smoother torque profile due to a high number of strokes per revolution.

A generator to generate electrical power from rotational motion and a method of making the generator. The generator includes a rotor including a plurality of magnetic poles; and a stator including a magnetic core comprising a body and teeth extending radially from the body and defining a plurality of slots therebetween. The stator also includes a first three-phase winding and a second three-phase winding, each of the first three-phase winding and the second three phase winding including first, second, and third phase windings comprised of coils individually wound around each of the teeth. At least two coils of each of the first, second, and third phase windings of the first three-phase winding and the second three phase winding are individually wound on teeth positioned next to each other.

An electric motor includes 3 stators and 1 rotor which employs distributed winding. The axial magnetic circuit generates permanent magnet torque, while the radial magnetic circuit generates reluctance torque. By decoupling the axial and radial magnetic circuits, the separation and the independent control of the permanent magnet torque and the reluctance torque are realized. Each stator and rotor can be processed independently, and modular installation can be processed, thereby reducing the difficulty of motor processing.

A motor device includes a motor housing, a stator core having at least two poles fixedly installed in the stator housing symmetrically, a coil winding wound around the stator core, and an insulating coil holder for insulating the stator core from the coil winding, and the motor device further includes at least two pairs of magnetic steel structures cooperating with the stator core. All of the magnetic steel structures are fixedly connected to the periphery of the shaft coupling, and the shaft coupling is fixedly connected to the motor shaft. An electric toothbrush having the above motor device is further provided.