A motor includes an annular core formed by stacking a plurality of electromagnetic steel sheets; end plates disposed at both ends of the core in an axial direction; a balance weight disposed on a side of one of the end plates, the side being opposite the core; and a spacer disposed between the one of the end plates and the balance weight, the spacer being configured to create a space between the one of the end plates and the balance weight. The motor is entirely fastened by allowing at least one of a plurality of rivets arranged in a circumferential direction of the core to pass through the core and the end plates in the axial direction, and allowing remaining at least one rivet to pass through the core, the end plates, the spacer, and the balance weight in the axial direction.

A stator core includes plate-shaped core members laminated to define the stator core. Each core member includes an annular core back portion, and tooth portions that project radially inward from an inner circumferential surface of the core back portion. The core back portion includes at least one recessed portion recessed radially inward from an outer circumferential surface of the core back portion, and at least one welded portion arranged at a corresponding one of the at least one recessed portion to join axially adjacent ones of the core members. The at least one recessed portion is recessed in a radial direction is in a range of about 0.2 mm to about 1.5 mm, both inclusive.

A rotor includes magnets, and a rotor core including thin film cores laminated in an axial direction and magnet holes in which the magnets are located. The rotor core includes first thin plate cores and second thin plate cores. The first thin plate cores include an annular first inner plate, first outer plates on a radially outer side of the inner plate and arrayed side by side in the circumferential direction, first inner connecting portions connecting the inner plate and the outer plate, and a first outer connecting portion that is on a radially outer side of the first outer plate and connects the adjacent outer plates in the circumferential direction.

A method of manufacturing a core product includes injecting molten resin into a resin injection portion provided in a core body so as to extend in a longitudinal direction of the core body, and forming a core product by welding the core body. A buffer region is set between the resin injection portion and a periphery of the core body in a lateral direction of the core body. The core product is formed by welding the core body so that a weld bead formed on the core body is prohibited from reaching the buffer region, and so that the weld bead is spaced apart from the resin injection portion in the lateral direction of the core body.

An EC motor for an electric hand tool having a stator in which a rotor is rotatably mounted, which comprises a rotor lamination stack, which has a passage opening and is formed of individual laminations, and a rotor shaft which is cast in the passage opening of the rotor lamination stack by means of a casting compound, and having a plurality of permanent magnets, which are received in the pockets formed in the rotor lamination stack. An annular channel, which is connected to the pockets in a fluid-conducting manner via radial channels, each of which is formed of a plurality of channel sections formed in adjacent laminations of the rotor lamination stack, is formed between the rotor shaft and the wall of the passage opening for supplying the casting compound from the annular channel to the pockets. A method is also provided for producing a rotor for an EC motor.

A motor includes a rotor rotatable about a central axis, and a stator opposing the rotor in a radial direction. The stator includes an annular core back and a stator core including teeth extending from the core back to one side in the radial direction. The stator core includes a laminated steel sheet in which electromagnetic steel sheets are laminated in a direction of the central axis. Each of the electromagnetic steel sheets includes a caulking dowel portion to which the adjacent electromagnetic steel sheets are connected by press-fitting. The caulking dowel portion includes a protrusion protruding from the core back to another side in the radial direction.

A rotor includes a shaft extending in an axial direction, a rotor core including laminations stacked in the axial direction, and at least one caulking portion at a radial-directional inner side of at least one magnet to caulk the laminations to each other. At least one magnet is embedded in the rotor core. At least one fixing portion fixes at least portions of outer peripheral edges of the laminations to each other. The caulking portion, the at least one magnet, and the at least one fixing portion are all arranged to be intersected by a straight line which is on a flat two-dimensional plane extending in a radial direction and a circumferential direction.

A hybrid stator core for an axial flux electric machine is described herein. The hybrid stator core includes a laminated component and at least one soft magnetic composite (SMC) component. The laminated component includes a first block section, a first tab, and a second tab, the first block section having a first end, a second end opposite the first end, a first side surface extending between the first and second ends, and a second side surface opposite the first side surface. The first tab projects from the first side surface adjacent to the first end of the first block section. The second tab projects from the first side surface adjacent to the second end of the first block section. The at least SMC component is configured to abut the first side surface of the first block section. The first and second tabs are configured to hold the at least one SMC component therebetween.

A stator core includes a core back having an annular shape around a central axis, teeth extending outward from the core back in a radial direction, and an inner peripheral surface located inside the core back in the radial direction and extending from an upper end to a lower end of the core back around the central axis. The core back includes a plastically deformable portion having an annular shape around the central axis and disposed below the core back in the axial direction. At least a portion of the plastically deformable portion has a different distance from the central axis than another portion of the core back.

A lamination stack for use in a rotating electrical machine includes a plurality of sheets of ferritic material. Each of the sheets has first and second sides that include asperities, and the asperities have a height of about two microns and a width of about two microns. A layer of electrically insulating material is provided between adjacent pairs of the ferritic sheets in the stack, and the asperities extend into the electrically insulating material.