Abstract: A laminated iron core includes laminated iron core pieces, in which coupling parts are formed so as to communicate in a lamination direction of the laminated iron core pieces, and the coupling parts are filled with resins. The laminated iron core satisfies the following formula: (T×S)/?>{(4×E×?×w×t3)/L3}×n, where T is a strength (N/mm2) of the resin; S is a cross-sectional area (mm2) of the coupling part or the resin; E is a Young's modulus (N/mm2) of the strip material; ? is a distortion amount (mm) of the iron core piece; w is a width (mm) of the iron core piece in a radial direction; t is a plate thickness (mm) of the iron core piece; n is the number of laminated iron core pieces; L is a distance (mm) between the coupling parts adjacent in the circumferential direction; and ? is a safety factor.

Abstract: A method for building a magnetic core including laminations bound into packs for an electrical machine comprises steps of: stacking a group of laminations one on top of the other to build the core; binding into a pack the group building the core by locking members that axially compress the group with a predetermined clamping force; pre-compressing, before clamping the pack by the locking members, the group by a pre-compression press that is independent and separate from the locking members; measuring an axial length of the group while the group is being compressed by the pre-compression press; initially forming the group with a normally lacking number of laminations to initially have the measured length that is lower than or substantially equal to a desired length; and adding, after having completed pre-compression, an additional number of laminations to the group determined according to a difference between the desired and measured lengths.

Abstract: The present invention provides a rotating electrical machine including a rotor core that does not produce narrow areas in rotor slots even if circumferential ends of fan-shaped segment cores are displaced radially outwardly and circumferentially during operation. In the present invention, slots near circumferential ends of the fan-shaped segment cores are made larger than slots in circumferential intermediate portions of the segment cores. With such a configuration, even if the circumferential ends of the segment cores are displaced radially outwardly and circumferentially during operation, the circumferential ends of the segment cores forming the large slots do not protrude into the slots formed in the circumferential intermediate portions of axially adjacent segment cores, thereby preventing narrow areas from being produced in the rotor slots.

Abstract: A rotor includes: a rotor core fixedly attached to a rotational shaft and having a magnet-inserted hole portion; a magnet inserted into the magnet-inserted hole portion; and a resin portion injected into the magnet-inserted hole portion. The rotor core is constructed by axially stacking a plurality of electromagnetic steel sheets. The electromagnetic steel sheets include: an electromagnetic steel sheet having the magnet-inserted hole portion and a weight-reducing-purpose hole portion provided separately from the magnet-inserted hole portion; and an electromagnetic steel sheet located on at least one axial end of the rotor core and having a portion covering the hole portion formed in the electromagnetic steel sheet.

Abstract: There is provided a method for manufacturing a stator core for an axial air-gap electronic motor, in which core sheets are laminatedly fixed while being shifted with predetermined intervals. The method includes a step in which first side surfaces in the circumferential direction (first slot surfaces 25) of the first to nth (n is a positive integer) core sheets are blanked out of a mother sheet 60 by moving first blanking punches 360 with predetermined intervals via a first control means 700; and a second blanking step in which second side surfaces in the circumferential direction (second slot surfaces 26) of the first to nth (n is a positive integer) core sheets are blanked in succession by moving a second blanking punch 460 with predetermined intervals via a second control means 700.