An aircraft propulsion system comprises a propulsor an electric motor coupled to the propulsor. The electric motor comprises a surface mounted permanent magnet electric machine comprising a rotor mounted radially inward of a stator. A Motor Diameter Ratio (MDR) is defined as an inner diameter (D.sub.stator,in) of the motor stator in metres divided by an outer diameter (D.sub.stator,out) of the motor stator in metres. The MDR of the electric motor stator is within 10% of the value given by the equation:

[00001]${\mathrm{MDR}=0.83\times (\frac{\mathrm{Torq}ue}{L_{active}}\times \frac{1}{U_{\mathrm{fan},\mathrm{tip}}})}^{0.08}$ where: T is the maximum torque rating of the electric motor in kilonewton metres; L.sub.active is the active length of the motor stator in metres; and U.sub.tip is the tip speed of the propulsor at the maximum rated torque of the electric motor in metres per second.

In the described embodiments, the MDR is less than 1.

A motor includes a housing including a housing base and a housing shaft portion that is provided on the housing base and extends in a direction along a rotation center axis, a motor stator that is disposed outward in a radial direction of the housing shaft portion, a motor rotor that is provided between the motor stator and the housing shaft portion, a bearing that is provided inward in a radial direction of the motor rotor and rotatably supports the motor rotor to the housing shaft portion, a sealing structure that is provided on an opposite side to the housing base in an axial direction of the motor rotor and seals between the motor rotor and the housing shaft portion, and a resolver that is configured to detect rotation of the motor rotor.

Electric motors and methods of controlling electric motors are described herein. The electric motors include a mobile component having at least one permanent magnet coupled thereto and a stator spaced apart from the mobile component. The stator includes at least one stator pole having a ferromagnetic core and a coil wrapped around the ferromagnetic core. The ferromagnetic core is naturally attracted to the at least one permanent magnet. The motors also include a magnetic position control system configured to monitor a position of the at least one permanent magnet relative to the stator and controllably deliver an electric pulse to the coil of each stator pole to generate a repulsive magnetic flux on the ferromagnetic core to cancel an attraction force between the ferromagnetic core and the at least one permanent magnet to control movement of the mobile component.

A stator includes: a stator core including an annular yoke portion and a plurality of tooth portions formed on an inner side in a radial direction of the yoke portion so as to be arranged at predetermined intervals in a circumferential direction and protrude toward the inner side in the radial direction; and a winding arranged in slots formed between the tooth portions. The stator includes cooling tubes made of a nonconductive material, extending in an axial direction of the stator, and serving as flow paths for a coolant. The cooling tube has a constant outer shape along the axial direction and has a thickness that changes along the axial direction.

A stator includes a stator core and a stator winding installed in the stator core. The stator winding has multiple conductor segments in which a conductor is coated with an insulating film 35. The conductor segment includes an exposed portion in which the conductor is exposed at its leading end, and a covered portion in which the conductor remains coated with the insulating film. At a coil end section of the stator winding, the exposed portions of different conductor segments are engaged with each other. A depression as a plastic deformation formed by crushing at least a part of the insulating film is provided at an edge of the covered portion of the conductor segment, located closer to the leading end of the conducting wire, thereby Providing a stator capable of suppressing peeling off of the insulating film and ensuring insulation reliability of the stator winding.

A hysteresis clutch including a first rotor with magnets that are polarized in opposite directions in pairs in a circumferential direction and between which pole pieces are provided for deflecting the magnetic flux in the radial direction and a second rotor of the hysteresis clutch has a series of second permanent magnets that extend in the circumferential direction and which are arranged on a circle that is concentric to the rotational axis A, the number of the first magnets and the number of the second magnet are configured such that a smooth torque curve is achieved which is free of a detent torque or at least has a low detent torque.

A permanent magnet rotor structure for an underwater motor, an underwater motor and underwater equipment, related to the field of motors. The permanent magnet rotor structure for the underwater motor includes a rotor end cover; a plurality of permanent magnets arranged on an inner circumferential surface of the rotor end cover; a protective attachment structure arranged on surfaces of the plurality of permanent magnets; and an adhesive layer for adhering the protective attachment structure to the surfaces of the plurality of permanent magnets and covering the protective attachment structure. The permanent magnet rotor structure has characteristics of corrosion resistance and wear resistance, so that the service life of the underwater motor comprising the permanent magnet rotor structure can be prolonged.

The present disclosure provides a rotor structure, a permanent magnet auxiliary synchronous reluctance motor and an electric vehicle. A rotor structure includes a rotor body. The rotor body has magnetic steel slot groups. Each of the magnetic steel slot groups includes an outer layer magnetic steel slot including: a first outer layer magnetic steel slot segment, a second outer layer magnetic steel slot segment, a first bent slot, and a second bent slot. The first outer layer magnetic steel slot segment and the second outer layer magnetic steel slot segment are arranged along a radial direction of the rotor body and are opposite to each other. Extended lines of a length directional geometric centerline of the first outer layer magnetic steel slot segment and a length directional geometric centerline of the second outer layer magnetic steel slot segment define a first angle.

An electric machine includes at least one stator having at least one individual-tooth winding carrier that has at least one spacer configured to space apart turns of an individual-tooth winding mounted on the individual-tooth winding carrier. A hybrid electric aircraft has an electric machine of this kind.

A setting tool driving fastening elements, comprising a holder for a fastening element; a drive-in element transferring a fastening element in the holder into a substrate along a setting axis by a setting energy E.sub.kin of at least 30 J and at most 600 J; a drive for driving the drive-in element toward the fastening element along the setting axis, the drive comprising a capacitor, a rotor on the drive-in element; and, an excitation coil, which during discharge of the capacitor is flowed through by current and generates a magnetic field accelerating the drive-in element toward the fastening element, the drive-in element having a piston diameter d.sub.K and a piston mass m.sub.K, and wherein, for d.sub.K, $\frac{2}{3}\left(a+b{E}_{kin}^n\right)\le d_K\le \frac{4}{3}\left(a+b{E}_{kin}^n\right)$
where a=33 mm, b=6 mmJ.sup.−n and n=⅓ and/or, for m.sub.K, $\frac{2}{3}\left(c+d{E}_{kin}^n\right)\le m_K\le \frac{5}{3}(c+d{E}_{k\mathrm{i<!--</p-->\; <div\; class="offcanvas\; offcanvas-end\; w-75"\; data-bs-scroll="false"\; data-turbo-permanent="true"\; id="chat">\; <turbo-frame\; loading="lazy"\; class="vstack\; h-100"\; id="sidebar\_chat"\; src="/chats"></turbo-frame>\; </div>\; <div\; class="toast-container\; position-fixed\; top-0\; end-0\; p-3"\; data-toast-container-target="container"></div>}}^{}$