Disclosed are: preparing a rotor core having a plurality of magnet holes spaced near a circumferential edge of the rotor core; preparing a plurality of permanent magnet units each including a porous body and a magnet main body disposed in contact with each other; and inserting the permanent magnet units into the magnet holes and securing the permanent magnet units in the magnet holes.

A flywheel energy storage system incorporates various embodiments in design and processing to achieve a very high ratio of energy stored per unit cost. The system uses a high-strength steel rotor rotating in a vacuum envelope. The rotor has a geometry that ensures high yield strength throughout its cross-section using various low-cost quenched and tempered alloy steels. Low-cost is also achieved by forging the rotor in a single piece with integral shafts. A high energy density is achieved with adequate safety margins through a pre-conditioning treatment. The bearing and suspension system utilizes an electromagnet that off-loads the rotor allowing for the use of low-cost, conventional rolling contact bearings over an operating lifetime of several years.

In one embodiment, a permanent magnet rotor is provided. The permanent magnet rotor includes at least one permanent magnet and a substantially cylindrical rotor core including an outer edge and an inner edge defining a central opening. The rotor core includes a radius R, at least one pole, and at least one radial aperture extending radially though the rotor core from the outer edge to a predetermined depth less than the radius. The at least one radial aperture is configured to receive the at least one permanent magnet. The rotor further includes at least one protrusion extending into the at least one radial aperture, the at least one protrusion positioned substantially along a bottom of the at least one radial aperture and configured to facilitate retention of the at least one permanent magnet within the at least one radial aperture.

A method of manufacturing a rotor for a rotating electric machine. The rotor includes a rotor core and at least one magnet fixed in at least one magnet fixing portion provided in the rotor core. The method includes: (a) placing the at least one magnet and at least one fixing member in the at least one magnet fixing portion such that each of the at least one fixing member is positioned between a corresponding one of the at least one magnet fixing portion and a corresponding one of the at least one magnet; and (b) applying an electric current to the at least one magnet to heat the at least one fixing member by heat generated by an electrical resistance of the at least one magnet, and fixing the at least one magnet to the at least one magnet fixing portion through the heated at least one fixing member.

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 fastening a magnet to a laminated core of a rotor for an electric motor includes providing the magnet and the laminated core, providing an adhesive tape, and winding the adhesive tape around the magnet to form a bondable magnet. The adhesive tape includes a backing tape formed by an open-pored nonwoven material, and an adhesive that coats only one side of the backing tape at room temperature and penetrates the open-pored nonwoven material and bonds to the laminated core of the rotor when a temperature of the adhesive is increased by at least 20° C. relative to room temperature. The laminated core may include a cavity for the bondable magnet, and the method may include the step of inserting or fitting the bondable magnet into the cavity. The bondable magnet may be inserted or fitted into the cavity without stress or mostly without stress.

A method of manufacturing a rotational electric machine rotor includes: forming a rotor shaft having a non-circular sectional outer shape; forming a rotor core by stacking a predetermined number of magnetic body thin plates each including a center hole having a non-circular shape corresponding to the non-circular sectional outer shape of the rotor shaft; and forming a protruding part for fixing the rotor core and the rotor shaft to each other by inserting the rotor shaft into the non-circular center hole of the rotor core and squashing the rotor shaft extending out of an axial-direction end face of the rotor core by using a predetermined swaging jig to expand the rotor shaft outward beyond an outer periphery of the non-circular section along the axial-direction end face of the rotor core.

A method of making a stator module for use in a stator assembly of an electric machine includes temporarily supporting a plurality of stator segments in a desired orientation using a temporary support. The desired orientation of the stator segments is a relative orientation of the stator segments within the stator module. A mold is placed around the plurality of stator segments and the mold is filled with a potting material to form a stator module such that the potting material supports the stator segments in their desired orientation. The temporary support is removed.

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.

In a method for producing a material layer with a layer thickness between 0.5 and 500 μm, a suspension with a binding agent and solid particles is applied through a template onto a base area for obtaining a green body. The binding agent is driven out of the green body and a permanent cohesion of the solid particles is created by heating and/or by compaction.