Systems and methods for connecting rotors between multiple permanent magnet motors. By coupling the rotors of multiple modules, torque may be transferred while maintaining the angular alignment between the stator and rotor magnetic fields of each individual permanent magnet motor.

An electric work machine with a product structure that effectively reduces noise caused by a brushless motor without changing the motor specifications. A hammer drill includes a brushless motor including a stator including an insulator, a cylindrical stator core, and a coil wound around the stator core via the insulator, and a rotor rotatable relative to the stator, a cylindrical member fixed along an entire outer circumference of the stator core and made of material with a Young's modulus higher than a Young's modulus of the insulator, and a housing accommodating the brushless motor and the cylindrical member.

An electric work machine with a product structure that effectively reduces noise caused by a brushless motor without changing the motor specifications. A hammer drill includes a brushless motor including a stator including an insulator, a cylindrical stator core, and a coil wound around the stator core via the insulator, and a rotor rotatable relative to the stator, a cylindrical member fixed along an entire outer circumference of the stator core and made of material with a Young's modulus higher than a Young's modulus of the insulator, and a housing accommodating the brushless motor and the cylindrical member.

An electric motor suitable for use in a laundry machine comprises an improved stator and/or rotor design.

The present invention relates to a rotating machine and a hoist. An object of the present invention is to provide a rotating machine and a hoist with improved cooling performance. A motor (10) includes: a stator (11) and a rotor (12); a rib part (12d) that rotates in accordance with rotation of the rotor (12), and a wind guide member (16) that guides wind taken in from a ventilation inlet (15aa) by rotation of the rib part 12d to a ventilation outlet (15ab).

A lamination ring for constructing a laminated rotor core for a rotor of an electric machine and a method for producing a laminated rotor core made of multiple lamination rings for a rotor is disclosed. The lamination ring has multiple receiving openings for permanent magnets, and multiple structural elements are arranged homogeneously in the lamination ring at the same distance to one another in the circumferential direction in a rotated manner by an offset angle relative to the axis of symmetry such that the arrangement of structural elements is not symmetrical relative to the axis of symmetry of the lamination ring.

A lamination ring for constructing a laminated rotor core for a rotor of an electric machine and a method for producing a laminated rotor core made of multiple lamination rings for a rotor is disclosed. The lamination ring has multiple receiving openings for permanent magnets, and multiple structural elements are arranged homogeneously in the lamination ring at the same distance to one another in the circumferential direction in a rotated manner by an offset angle relative to the axis of symmetry such that the arrangement of structural elements is not symmetrical relative to the axis of symmetry of the lamination ring.

A motor rotor includes an inner sleeve, a cylindrical permanent magnet disposed around the inner sleeve, and a resin portion formed by charging a gap between the inner sleeve and the permanent magnet with a resin. The inner sleeve includes a small diameter portion. The small diameter portion is located to face an inner peripheral surface of an end portion of the permanent magnet in an axial direction. The small diameter portion is formed to have a diameter smaller than a diameter of a portion facing an inner peripheral surface of a center portion of the permanent magnet in the axial direction.

A motor rotor includes an inner sleeve, a cylindrical permanent magnet disposed around the inner sleeve, and a resin portion formed by charging a gap between the inner sleeve and the permanent magnet with a resin. The inner sleeve includes a small diameter portion. The small diameter portion is located to face an inner peripheral surface of an end portion of the permanent magnet in an axial direction. The small diameter portion is formed to have a diameter smaller than a diameter of a portion facing an inner peripheral surface of a center portion of the permanent magnet in the axial direction.

A rotor includes a rotary shaft and a rotor body supported by the rotary shaft. The rotor body includes a first permanent magnet and a second permanent magnet. The first permanent magnet has a first overhang part that is in contact with a first end part of the second permanent magnet in an axial direction of the rotary shaft, and the first overhang part and the first end part are joined to each other. A motor includes the rotor and a stator.