A stator includes a yoke extending in a circumferential direction about an axis line, a tooth extending from the yoke in a first direction toward the axis line, and a coil wound around and fixed to the tooth. The yoke has an inner wall surface facing the axis line. The tooth has a root part connected to the yoke. The inner wall surface of the yoke is a flat surface extending from an end of the root part of the tooth in the circumferential direction to an inner circumferential side relative to a plane passing through the end and perpendicular to the first direction.

A stator includes a yoke extending in a circumferential direction about an axis line, a tooth extending from the yoke in a first direction toward the axis line, and a coil wound around and fixed to the tooth. The yoke has an inner wall surface facing the axis line. The tooth has a root part connected to the yoke. The inner wall surface of the yoke is a flat surface extending from an end of the root part of the tooth in the circumferential direction to an inner circumferential side relative to a plane passing through the end and perpendicular to the first direction.

A motor drive system with a rotor assembly having an insert, which is received into a blind hollow rotor space in a rotor shaft. The insert is unitarily and integrally formed and defines a central hole, which is disposed along a rotational axis of the rotor assembly, and a plurality of slots that extend through an outer circumferential surface of the insert. The insert is disposed in the rotor shaft such that the outer circumferential surface of the insert is engaged to the inside circumferential surface of the rotor shaft. The central hole forms a first fluid passage through the insert, while the slots form a plurality of second fluid passages through the insert.

Disclosed is a motor, the motor according to exemplary embodiments of the present disclosure including an insulator body coupled to a stator core wound with a plurality of coils applied with powers of mutually different polarities to prevent the coil and the stator coil from being short-circuited, a terminal housing coupling unit integrally formed with the insulator body to be coupled to a terminal housing supplying an outside power by being circumferentially protruded, and a coil guide unit formed at the terminal housing coupling unit to prevent coils connected to a terminal of each polarity installed at the terminal housing from being short-circuited.

The present invention relates to a rotary micromotor (10) designed for actuating an abrasive blade (4) of a surgical or dental tool, the motor comprising a rotor (11) co-operating with a stator (12), and being characterized in that the rotor (11) has a hollow central tubular portion, and comprises an outwardly polarized Halbach array.

A motor rotor includes a shaft body, a cylindrical magnet covering an outer circumferential surface of the shaft body, a cylindrical protective layer covering an outer circumferential surface of the magnet and an annular end ring having the shaft body inserted therethrough, and in contact with an end surface of the magnet. The end ring is fixed to the shaft body by an inner circumferential resin portion formed between an inner circumferential surface of the end ring and the outer circumferential surface of the shaft body.

A torque delivering apparatus, including: polygonal cross-section stator body having a plurality of exterior side faces of even number extending between opposite axial end faces, the stator including cylindrical bore extending between the opposite axial ends and centred on central axis of the stator body; a rotor assembly having cylindrical cross-section sized for rotation within the cylindrical bore about the central axis with at least one permanent magnet and shaft coupled to the magnet for rotation; and a plurality of solenoid coils, each coil having plurality of windings and routed to have sections extending parallel along opposite ones of the plurality of exterior side faces; wherein each of the plurality of coils is configured to selectively receive current and generate magnetic field in the stator that is applied to the rotor magnet, the rotor being subject to magnetic torque within the cylindrical bore for rotating and aligning the magnetic field of the permanent magnet with the generated magnetic field.

A method for reducing stress concentration on a rotor sleeve during balance cutting comprising: providing an axial protrusion to an outer diameter of a first end cap and a second end cap of a rotor assembly; and radially cutting at least one of the sleeve or the axial protrusion to balance the rotor assembly.

A vacuum pump for rotary driving a rotor by a motor to perform vacuum pumping, wherein a motor rotor of the motor includes a yoke fixed to a shaft of the rotor, and a permanent magnet held at the yoke, and the yoke includes a holding portion provided apart from the shaft and configured to hold the permanent magnet, and a pair of fitting portions provided respectively at both ends of the holding portion in an axial direction and bonded to the shaft by fitting, and a radial thickness dimension of each fitting portion is set less than that of the holding portion.

A pump for a water-conducting appliance, the pump having an electric motor comprising: a rotor comprising a ferrite body with at least four magnetic poles, wherein the ferrite body has a lateral-circumferential magnetization; and a stator comprising a pole chain made of a stack of a plurality of straight transformer sheets and rounded to a circular configuration by bending the stacked transformer sheets, wherein the pole chain has a plurality of pole portions each comprising a pole tooth; and a plurality of winding cores attached to the respective pole teeth for accommodating coils of a three-phase winding comprising wires; wherein the wires of respective phases of the three-phase winding are routed spatially separated from each other and without mutual contact at an axial end surface of the pole chain between and along adjacent winding cores around the pole chain; and wherein the wires are supported and guided such that their positions relative to the pole chain are substantially maintained when the pole chain is rounded from its straight configuration to its circular configuration.