An electric machine designed as a permanently excited synchronous machine, including a rotor with a rotor body arranged on a rotor shaft, a stator, and a displacement device that generates a relative axial movement between the rotor body and the stator based on a torque produced between the rotor shaft and the rotor body. The displacement device has first and second displacement elements and at least one rolling body arranged between the first and second displacement elements. The first displacement element is axially movable and rotatable to a limited degree on the rotor shaft, and the second displacement element is connected to the rotor shaft rotationally fixed. The displacement elements provide that upon rotation of the first displacement element relative to the second or vice versa, the rotor body is pushed on the rotor shaft axially against the spring force.

An electric axial flow machine having a stator, a first rotor body arranged on a rotor shaft, a second rotor body arranged on the rotor shaft, and a displacement device arranged between the two rotor bodies and coupled thereto. The displacement device includes at least one spring device which acts on the first rotor body and the second rotor body against the magnetic attractive force between the rotor body and the stator. The spring device is configured such that a spring force characteristic is formed which runs above the magnetic force characteristic over the entire displacement path.

A system for a rotor with directional magnetic field configured for use in electric aircraft motor that includes a magnet array having an outer cylindrical surface, an inner cylindrical surface, an upper edge, and a lower edge, which further includes a plurality of magnets, where the plurality of magnets is configured to create a directional magnet field and an electrically insulating epoxy, where the electrically insulating epoxy envelops at least a portion of the plurality of magnets.

A system for a rotor with directional magnetic field configured for use in electric aircraft motor that includes a magnet array having an outer cylindrical surface, an inner cylindrical surface, an upper edge, and a lower edge, which further includes a plurality of magnets, where the plurality of magnets is configured to create a directional magnet field and an electrically insulating epoxy, where the electrically insulating epoxy envelops at least a portion of the plurality of magnets.

An actuator for generating vibration, including a shaft; a middle supporter having a fitting portion fitted into an upper portion of the shaft and a support portion below the fitting portion to form a first space where a lower portion of the shaft is exposed; a circuit board having a driving coil and a hollow formed through the middle supporter; a housing having an inner space that accommodates the middle supporter and the circuit board so the circuit board is fixed thereto; a first yoke plate having a first magnet installed to face an upper surface of the driving coil and coupled to an upper portion of the middle supporter; a second yoke plate having a second magnet installed to face a lower surface of the driving coil and coupled to a lower portion of the middle supporter; and a weight installed to at least one of the yoke plates.

We describe a method and controller for controlling an axial flux machine in which an alternating current supplied to the plurality of coils injects a compensation current to reduce a mechanical resonant component of the rotor. The compensation current is a modulated current component added to at least one of the Quadrature Current (Iq) and Direct Current (Id) components (when the alternating current is represented as a vectored DC component), when the rotor is rotating over one or more ranges of rotational speeds. The modulated current component has an electrical frequency that varies over a range of frequencies between a first frequency and a second frequency depending on the rotational speed of the rotor, the range of frequencies including a frequency that is substantially the same as a fundamental mechanical resonant frequency of the rotor, and having a phase that is out of phase with the fundamental mechanical resonant frequency of the rotor.

We describe a method and controller for controlling an axial flux machine in which an alternating current supplied to the plurality of coils injects a compensation current to reduce a mechanical resonant component of the rotor. The compensation current is a modulated current component added to at least one of the Quadrature Current (Iq) and Direct Current (Id) components (when the alternating current is represented as a vectored DC component), when the rotor is rotating over one or more ranges of rotational speeds. The modulated current component has an electrical frequency that varies over a range of frequencies between a first frequency and a second frequency depending on the rotational speed of the rotor, the range of frequencies including a frequency that is substantially the same as a fundamental mechanical resonant frequency of the rotor, and having a phase that is out of phase with the fundamental mechanical resonant frequency of the rotor.

An electric motor, at least having a stator and an annular rotor which are arranged next to one another along an axial direction; wherein the stator has a plurality of stator teeth which are arranged next to one another along a circumferential direction and which each extend along the axial direction. At least one coil has at least one turn is arranged on each stator tooth, wherein the at least one turn is electrically conductively connected to a printed circuit board. The printed circuit board is arranged on an end side of the stator and next to the stator along the axial direction. The printed circuit board comprises a plurality of electrical connecting lines via which the at least one turn of each coil is connected at least to other turns or to an electrical connection of the motor.

A brushless DC motor (BLDC) includes a stator having a ring-shaped body with multiple stator posts extending axially outward from the ring-shaped body. A plurality of stator windings are each wound about a corresponding one of the stator posts. A rotor support structure is positioned radially inward of the multiple stator posts. A rotor including a shaft is received in the rotor support structure. A first rotor disk is fixed to a first end of the shaft. At least a first set of magnets is disposed about the rotor disk and positioned radially adjacent to the stator posts such that the first set of magnets and the stator windings define a first radial flux flowpath. A second set of magnets positioned relative to the stator posts in one of an axial adjacency or a radial adjacency such that a second flux flowpath is defined.

A device has a housing and rotors rotatably coupled to the housing. Each rotor has a magnet on at least one side of the rotor. Printed circuit board (PCB) stators are located axially between the rotors and coupled to the housing. The PCB stators have layers, and each layer has coils. The number of rotors disks is equal to the number of stators plus one. The stators are interleaved with the rotors. A shaft is coupled to the rotors and the housing. The shaft has a hollow section coupled to a source of a liquid coolant through a rotary connector and to radial channels in the shaft that dispense a liquid coolant between the rotors and PCB stators. The shaft has flanges with different diameters configured to receive the rotors disks with respective matching bore diameters. In addition, the housing has a sump to collect the liquid coolant.