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.

A device and a method for connecting lamination parts to form a lamination stack, in which lamination parts are punched out from an electrical strip that is coated on at least one of its flat sides with a hot-melt adhesive varnish layer, the lamination parts that have been punched out are stacked, and then connected in an integrally joined manner through thermal activation of the hot-melt adhesive varnish layer to form a plurality of lamination stacks. Before the lamination parts are punched out, the electrical strip is prepared in a subregion of the hot-melt adhesive varnish layer in such a way that after the lamination part is punched out, this lamination part facilitates separation of the stacked lamination parts into lamination stacks. In the preparation of the electrical strip, the layer thickness of the hot-melt adhesive varnish layer on the electrical strip is at least reduced through removal by laser light in order to produce the subregion.

A dynamo-electric machine includes a stator, a rotor disposed in the stator, a bottomed tubular case that accommodates the stator, an end cover mounted on an open end of the case, and a circuit substrate that controls driving of the dynamo-electric machine. The stator includes a core having portions that protrude toward a center of the stator, insulators mounted on the stator core, and a coil wound around each of the protruding portions with the insulators therebetween. The circuit substrate is disposed inward of an outer end of the case and is disposed between the stator and the end cover, and includes a first insulation sheet disposed between the circuit substrate and the stator to insulate the circuit substrate and the coil; and a second insulation sheet disposed between the circuit substrate and the end cover to insulate the circuit substrate and the end cover.

A dynamo-electric machine includes a stator, a rotor disposed in the stator, a bottomed tubular case that accommodates the stator, an end cover mounted on an open end of the case, and a circuit substrate that controls driving of the dynamo-electric machine. The stator includes a core having portions that protrude toward a center of the stator, insulators mounted on the stator core, and a coil wound around each of the protruding portions with the insulators therebetween. The circuit substrate is disposed inward of an outer end of the case and is disposed between the stator and the end cover, and includes a first insulation sheet disposed between the circuit substrate and the stator to insulate the circuit substrate and the coil; and a second insulation sheet disposed between the circuit substrate and the end cover to insulate the circuit substrate and the end cover.

An interior permanent magnet rotor, for a drive unit disposed in the interior of a hermetically sealed housing of a refrigerant compressor, whereas the rotor includes a first axial section with permanent magnets, followed by a second axial section without permanent magnets. In order to reduce the risk of a magnetic short-circuit it is provided that the second axial section, adjacent to the first axial section, includes a first axial subsection with a reduced radial dimension not going beyond the permanent magnets in the first axial section, whereas the axial length of the first axial subsection is smaller than the axial length of the first axial section, and the second axial section, adjacent to its first axial subsection, includes a second axial subsection with a radial dimension larger than the reduced radial dimension of the first axial subsection.

A motor case has a first case portion and a second case portion coupled to the first case portion. The stator has a stator core and an insulator fixed to the stator core. The insulator has a tubular portion having an outer circumferential surface and a polygonal shape in the cross-sectional view, and on the outer circumferential surface, insulator flat portions lined up in a circumferential direction. The first case portion includes: three or more core supports which project inward in the radial direction from an inner circumferential surface of a circumferential wall of the first case portion, come into contact with the core outer-circumferential surface, and are disposed at intervals from each other in the circumferential direction; and at least one first detent which is in contact with or is disposed to come into contact with the insulator flat portion.

A motor case has a first case portion and a second case portion coupled to the first case portion. The stator has a stator core and an insulator fixed to the stator core. The insulator has a tubular portion having an outer circumferential surface and a polygonal shape in the cross-sectional view, and on the outer circumferential surface, insulator flat portions lined up in a circumferential direction. The first case portion includes: three or more core supports which project inward in the radial direction from an inner circumferential surface of a circumferential wall of the first case portion, come into contact with the core outer-circumferential surface, and are disposed at intervals from each other in the circumferential direction; and at least one first detent which is in contact with or is disposed to come into contact with the insulator flat portion.

A motor has a rotor, a stator surrounding the rotor, a reinforcing member, and a mold resin part covering the stator and the reinforcing member. The tensile strength of the reinforcing member is higher than the tensile strength of the mold resin part.

A motor has a rotor, a stator surrounding the rotor, a reinforcing member, and a mold resin part covering the stator and the reinforcing member. The tensile strength of the reinforcing member is higher than the tensile strength of the mold resin part.

A rotor assembly includes a rotor core having an axial length and configured to rotate about a longitudinal axis and at least one permanent magnet disposed about a radially outer surface of the rotor core. The rotor assembly further includes an electrical insulator disposed between the radially outer surface of the rotor core and the at least one permanent magnet and configured to disrupt an electrical conduction path along the axial length of the rotor core.