An electric motor comprises a stator (1, 5, 8) having an air-gap which extends around an axis and in which a rotating magnetic field is generated, and a rotor (11, 12, 13) comprising a shaft (11) which is rotatably held by a bearing (10) and a permanent magnet (13) which is held in said air-gap and is driven to rotate around said axis by said rotating magnetic field. The stator (1, 5, 8) is adapted to generate, in addition to said rotating magnetic field, a stationary magnetic field which is rot...

A stator for an electrical machine is proposed that has a stator winding (45) that is held by a stator core (10) that is formed into an annular shape. The stator core (10) has grooves (14) and teeth (13) on its radially inwardly oriented circumference. The stator core (10) is composed of layered stator sheet metal lamellae (11), the direction of the layers defining an axial direction (a). It is provided that at least a first stator sheet metal lamella (20) has a higher flexural strength than sec...

An electric motor or generator assembly includes a component, such as a stator, having a plurality of windings. A wire set including a plurality of individually conductive wires twisted together is manipulated within a core to establish the desired number of windings having the desired cross sectional area. In one example, a plurality of such wire sets are manipulated simultaneously to establish the windings. Litz wire is one example type of wire set that is useful in an assembly designed accord...

In axial magnetic bearing apparatus in which a rotary disc made of a magnetic material is fixedly attached to a rotating shaft, and electromagnets are disposed on opposite sides of the rotary disc so as to have suitable very small distances therefrom respectively, so as to bear the rotating shaft axially in a non-contact state, a deep groove for forming an air layer having large magneto-resistance is provided all over the outer circumference of the rotary disc. Thus, formation of a magnetic circ...

An electric motor has a field assembly, such as a stator, has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assem...

An electric motor, power tool using the electric motor, and method of making the electric motor includes making a stator that includes pole portions that have axial lengths less than an axial length of a back iron portion. Alternatively, or in addition, the pole portions have axially opposed ends that decrease in width. Alternatively, or in addition, the pole portions have dovetail features that are received in corresponding recesses of the back iron portion.

An electric motor, power tool using the electric motor, and method of making the electric motor includes making a stator that includes pole portions that have axially opposed ends that gradually decrease in width. The pole portions may also have dovetail features that are received in corresponding recesses of the back iron portion.

In axial magnetic bearing apparatus in which a rotary disc made of a magnetic material is fixedly attached to a rotating shaft, and electromagnets are disposed on opposite sides of the rotary disc so as to have suitable very small distances therefrom respectively, so as to bear the rotating shaft axially in a non-contact state, a deep groove for forming an air layer having large magneto-resistance is provided all over the outer circumference of the rotary disc. Thus, formation of a magnetic circ...

A stator (50) for an electrical machine. A core of the stator (50) is made up of a series of connected segments (42), that are rotatable relative to one another during an assembly operation. Each segment (42) includes a radially outermost base portion (44) from which a respective integral pole piece (46) projects substantially inwardly to a pole piece tip. The tip includes a surface (49) that is arcuate and concentric with an axis of rotation of the machine. Each pole piece (46) projects in a no...

A brushless motor includes a rotor having a permanent magnet magnetized N pole and S pole alternately in a rotary direction, and a stator having a core facing the permanent magnet in a radial direction and a bearing which rotatably supports the rotor. The core includes plural salient poles at its ends, and slot inclusive-angle A, slot inclusive-angle B, slot inclusive-angle C are available between the salient poles adjacent to each other. When a relation of A<B<C is found, those slot inclu...