An EC motor is provided having a stator, in which an armature is rotatably supported, the armature including an armature shaft, on which an armature core having a plurality of permanent magnets is held, the armature core being electrically insulated against the armature shaft with the aid of a casting compound, and a balance ring being provided on at least one axial end of the armature core, which is accommodated on the armature shaft by a central recess, a gap between the armature shaft and the central recess of the balance ring being filled with casting compound, and the permanent magnets being held in pockets of the armature core by casting compound.

A rotor includes an assembly of laminations including a plurality of radially-projecting poles, a winding of electrically conductive wires to be wound around each pole by means of wire-guiding heads arranged axially on either side of the lamination assembly. A guiding head support is inserted between the lamination assembly and each guiding head such that: an internal radial face of the support abuts against an external radial face at an axial end of the lamination assembly; and a peripheral surface of the support, which projects axially outward from the internal radial face of the support, is in contact with a contact face of the guiding head that is orientated radially outward from same, the guiding head abutting against the peripheral surface of the support.

An oscillating power tool with an electric motor is provided, including an armature shaft with an armature and a fan wheel, including an eccentric arranged on the armature shaft at one end thereof, a first balancing mass for balancing an unbalance of the eccentric and possibly an eccentric bearing, being arranged in the proximity of the eccentric or the eccentric bearing, respectively, however, at an axial distance, further including a second balancing mass for balancing a couple unbalance caused by the axial distance between the eccentric and the eccentric bearing, respectively, and the first balancing weight, wherein the second balancing mass is arranged on the armature shaft at the side facing away from the eccentric or the eccentric bearing. Also a method for balancing such an electric motor is provided.

An electric machine assembly including a body part; a stator stationarily supported to the body part; a rotor adapted to rotate relative to the stator, and adapted to receive a shaft inside thereof; and a locking system for providing a locking state for the electric machine assembly in which the rotor is locked relative to the stator. The locking system includes at least one locking member adapted to be in a separating position between the rotor and the stator; and a plurality of radial bolt holes provided in the rotor, extending in a radial direction, and adapted to receive centring bolts such that distal ends of the centring bolts press the at least one locking member in the separating position radially outwards relative to the rotor.

The disclosure relates to a rotor for an electric motor, having a laminated rotor core which is rotatable about a rotation axis and has a first rotor lamination and a second rotor lamination, which is arranged axially next to the first motor lamination, and having a plurality of magnet cutouts in each of which magnets are arranged and secured. The disclosure further relates to an electric motor having a rotor and a method for reducing the unbalance of a rotor.

A speed reducer comprises a transmission shaft, an eccentric wheel, a first wheel assembly, a rotating wheel and a second wheel assembly. The first wheel assembly comprises a first wheel disc and at least one first roller. The at least one first roller is disposed on the inner wall of first wheel disc. The rotating wheel comprises a main body comprising an outer ring structure and a concave structure. The outer ring structure comprises at least one first tooth. The at least one first tooth is in contact with the corresponding first roller. At least one second roller is disposed within the concave structure. The second wheel assembly comprises a second wheel disc and at least one second tooth. The at least one second tooth is disposed on an outer periphery of the second wheel assembly. The at least one second tooth is in contact with the corresponding second roller.

A rotor of a dynamo-electric rotary machine includes a rotor core arranged concentrically to a rotor axis and including slots filled with electrically conductive material. A front ring is arranged at a front axial end of the slots and includes electrically conductive material, and a rear ring is arranged at a rear axial end of the slots and includes electrically conductive material. A rotor-core-distal surface of the front ring and/or rear ring has a bevel in axial direction from an outer circumference to an inner circumference, with the bevel defined by a bevel angle having a value of 3° to 30°. A support element is at least partially connected to the front and/or rear ring with a positive fit and pressed thereon axially, with the support element being supported on a shaft and having a radial end which terminates at a radial end of the front and/or rear ring.

To provide an electric motor enabling easy and high-precision balance correction even after operating over a long period, and a machine toll including this electric motor. An electric motor includes: a cylindrical stator; a rotor having a rotary shaft part inserted inside of the stator; a housing installed to both ends in an axial direction of the stator; a terminal box that is mounted to the housing and accommodates a terminal block; an opening provided so as to open within the terminal box through the housing, and disposed to be separated from a ventilation passage formed in the stator; and a first balance correction component that is installed to the rotary shaft part, and corrects balance of the rotor, in which the first balance correction component is exposed within the terminal box from the opening; and a machine tool includes this electric motor.

An electric drive unit and method of assembling the same is disclosed. The electric drive unit includes a rotor having a rotor shaft, and gear shaft, where the rotor shaft is inserted into the gear shaft. The gear shaft is supported by two bearings, while the rotor shaft supported directly at one end by a bearing and at the other by the gear shaft. A wave spring is also disclosed that provides an axial loading to the rotor shaft. Also disclosed is a balancing ring secured to an end of the rotor via a locknut. The balancing ring can be machined in order to balance the rotor. The rotor shaft can be connected to the gear shaft via a spline connection. The rotor shaft can bear against the gear shaft via a pilot journal and pilot bore defined on the rotor shaft and gear shaft respectively.

A rotor for a rotary electric machine, the rotor having an axis of rotation and including a rotor shaft extending parallel to the axis of rotation, a rotor body mounted on the rotor shaft and having a plurality of teeth protruding radially, and at least one field coil wound around the plurality of teeth, the field coil forming coil ends at axial ends of the teeth. At least one cover mounted on the rotor shaft and configured to cover the coil ends. The cover includes a plurality of holes configured to each receive a solid balancing element which provides an additional mass to the rotor in order to balance said rotor.