The present invention is a variable air gap in a rotary electric machine, notably a permanent magnet-assisted synchronous reluctance electric machine.

A lubricant supported electric motor includes a stator presenting an outer raceway and a rotor extending along an axis and rotatably disposed within the stator. The rotor presents an inner raceway disposed in spaced relationship with the outer raceway to define a gap therebetween, and a lubricant is disposed in the gap for supporting the rotor within the stator. At least one of the outer raceway or the inner raceway is movable radially towards or away from the other to adjust the gap and optimize operation of the lubricant supported electric motor.

An electrical machine includes a first stator having a stator core and a plurality of windings, and a movable element that is movably mounted adjacent to the first stator to form a first air gap between the movable element and the windings of the first stator. The movable element is a slider or a rotor connected to a shaft. A second stator includes a stator core arranged opposite to the first stator on the other side of the movable element. The movable element is movably mounted adjacent to the second stator to form a second air gap between the movable element and the stator core of the second stator. The first stator, the second stator and the movable element are arranged to pass the magnetic flux passes from the first stator through the first air gap, through the movable element and through the second air gap to the second stator.

A rotor for an electric machine of a vehicle. The rotor includes permanent magnets, receptions for the permanent magnets and deformation components. The permanent magnets are adapted to be deformed elastically and are arranged within the receptions, which are designed such that the permanent magnets may deform within the receptions. The deformation components are adapted to deform the permanent magnets such that at least one of a magnetic induction, a conductor length and a rotor radius is adjusted.

An electric stepper motor is disclosed. A group of permanent magnets are physically attached to a group of piezoelectric actuators which push them toward or pull them away from a second group of permanent magnets when the piezoelectric actuators are electrically activated, producing a very precisely controllable stepper motor. The second group of permanent magnets may also be pushed and pulled with a second group of piezoelectric actuators. Alternate configurations using electromagnets are also disclosed.

A novel configuration for the groups of electromagnets which maximizes efficiency in a piezoelectrically actuated motor is also disclosed.

A linear drive unit and a machine tool having the linear drive unit, capable of being applied to various applications, while taking into consideration the balance between the thrust force and the cogging of a linear motor. The linear drive unit has a magnetic gap changing mechanism which is configured to change a magnitude of a magnetic gap between a coil and a magnet, by displacing at least one of the coil and the magnet so that the coil and the magnet approach or are separated from each other.

An electric motor having low vibration and/or noise comprises a rotor or stator comprising permanent magnets each comprising at least two pole pairs, with an internal flux gap within the permanent magnets between adjacent internal pole pairs. The internal flux gap between the internal pole pairs may be similar to an external pole to pole physical spacing between adjacent poles of adjacent magnets. The motor is suitable for use in for example a laundry washing machine or dryer or washer-dryer.

The purpose of the present invention is to provide an electric generator which allows the magnitude of mutual magnetic action between a rotor and an armature to be self-adjusted in the electric generator against a fluctuation in a motive power or a fluctuation in an electric load, such that the magnitude of an induced electromotive force is controlled to compensate, with voltage variation, for amounts of the fluctuation in the motive power and the fluctuation in the electric load and to induce electricity with a uniform frequency from the electric generator, while stabilizing the prime mover or load devices, and parts optimized for the same. To this end, the present invention has an iron-piece structure in which the rotor and the armature of the electric generator mutually correspond to each other in a concave-convex structure, and the present invention is configured to be able to control the magnitude of the induced electromotive force, as the armature moves in the axial direction in response to a change in the rotation speed, output voltage, or frequency of the electric generator and, thereby, variably controls a mutually corresponding length of the concave-convex structure.

An electric machine includes a stator and a rotor positioned in operational engagement with one another and defining a radial gap extending circumferentially between the stator and the rotor, the rotor including a plurality of rotor segments defining a plurality of segment gaps between adjacent pairs of the plurality of rotor segments, the rotor segments radially moveable relative to the stator, wherein movement of the plurality of rotor segments radially outward increases the radial gap between the stator and the rotor and the segment gaps between adjacent pairs of the plurality of rotor segments.

An internal rotor for an electric machine includes a rotational axis, an outer circumferential face which delimits the internal rotor, a pole arrangement comprising a centroid, and an actuating mechanism for moving the pole arrangement towards the rotational axis or away from the rotational axis to set a first spacing between the outer circumferential face and the centroid. In an example embodiment, the actuating mechanism has an actuator for moving the pole arrangement. The actuator has a hydraulically operable piston, a pneumatically operable piston, an electric motor actuator, or converts an axial force to a radial force. In an example embodiment, the actuating mechanism is operatively connected to the pole arrangement. The actuating mechanism is arranged between the rotational axis and the pole arrangement, or the actuating mechanism is arranged between the outer circumferential face and the pole arrangement.