A material layer for a laminated core of an electric machine is made of iron-containing ferromagnetic material and includes an electrically insulating coating on at least one side of the material layer. The electrically insulating coating Includes an electrically Insulating material which Is produced through controlled oxidation of the ferromagnetic material of the material layer and contains iron monoxide and/or triiron tetraoxid. The material layer is produced from a green body, which Is sintered under a reducing atmosphere.

Methods of estimating tribological damage described herein include examples where varying power is applied between surfaces engaged in frictional contact. Calculations evaluate power consumed at the relevant frictional contact and temperature values may be gathered to supplement the calculated power. Instantaneous and cumulative assessments of damage are calculated based on that information. Measurements or calculations of electrical power may be used as part of the damage assessment.

An armature winding includes a plurality of winding segments each of which is made of a winding of a conductor wire member. The winding segments are arranged at a given interval away from each other in a circumferential direction of the armature winding and face a magnet unit. Each of the conductor wire members is made of a bundle of a plurality of wires. Each winding segment includes a pair of straight portions and link portions. The straight portions extend straight in an axial direction of a rotor. The link portion connect the straight portions together. Each of the straight portions is made of turns of the conductor wire member which are arranged in the form of multiple columns and layers. Each link portion is shaped to have a space factor lower than those in the straight portions of the winding segment.

A plurality of plate-like magnets are partially bonded at a predetermined interval to an inner circumferential surface of a rotor yoke with a first adhesive via a positioning member for positioning in a radial direction and in an axial direction, and a second adhesive is heat-cured in a state where the positioning member is removed, thus bonding and fixing the plurality of plate-like magnets at a predetermined interval and spaced apart from each other in a circumferential direction.

A rotor for a rotary electric machine includes a rotor shaft configured to rotate around an axis of rotation, a rotor body formed of a stack of laminations having a plurality of teeth projecting radially and being configured to be mounted coaxially on the rotor shaft. A field coil is wound around each tooth of the plurality of teeth. At least one tooth of the plurality of teeth includes at least one weld seam on a lateral face of the corresponding tooth, the lateral face extending radially and axially along the axis of rotation.

A magnetizing method applies, to a rotor including a plurality of magnetic bodies that are arranged in the circumferential direction of the rotor and are to be magnetized, a magnetic field in a radial direction of the rotor to magnetize the magnetic bodies. The magnetizing method includes a step of arranging a magnetizing coil near the outer peripheral portion of the plurality of magnetic bodies and a step of applying a radially outward magnetic field only to one of the magnetic bodies while applying radially inward magnetic fields to the plurality of magnetic bodies.

There are provided a laminated iron core, a manufacturing method thereof, and a progressive die machine, in which the laminated iron core includes: a plurality of iron core pieces which are laminated; adhesives that bond the iron core pieces adjacent to each other. Each of the iron core pieces includes an annular yoke portion and a plurality of teeth portions projecting radially from the yoke portion. Each of the adhesives is arranged at a different radial distance from a central axis of the iron core pieces and is evenly arranged in a circumferential direction of the iron core pieces on at least one of the entire yoke portion and the entire teeth portions.

A rotor manufacturing method is a method that allows magnetized magnets inserted in second magnet holes of a second rotor core to be inserted, while retaining magnetism, into first magnet holes of a first rotor core. This method includes a placing step of placing the second rotor core on a first end surface, in a stack thickness direction, of the first rotor core such that the second magnet holes overlap the first magnet holes, and an extruding step of extruding the magnetized magnets from the second magnet holes toward the first magnet holes using a non-magnetic jig.

A method for manufacturing a stator of an axial flow electric machine includes cutting slots on a lateral part of a strip of sheet metal, cutting recesses on an opposite lateral part of the strip to form coolant flow channels, winding the strip according to a radial stack, the recesses being cut by a double perforation symmetrical to a line orthogonal to the length of the strip, the recesses being cut on a first radial periphery of the stator winding at a distance from the radial section of the stator passing through the line, until they meet on the radial section at an opposite radial periphery of the stator winding, forming V-shaped channels meeting at the ends of the legs of the V's during the winding.

A method for manufacturing a rotor or a rotary electric machine having magnet holes. The method includes a step of preparing a plurality of steel sheets punched out of a material by pressing, a step of stacking the plurality of steel sheets to form a rotor core, a step of causing plastic strain by applying mechanical energy or high-density energy to at least one steel sheet out of the plurality of steel sheets, and a step of applying heat to the steel sheet in which the plastic strain has been caused.