Provided are a motor core having excellent fatigue resistance and a method of manufacturing the motor core at a low cost. The motor core that is an electrical-steel-sheet-stacked body has an outer peripheral surface in which an appearance ratio of recrystallized grains with a grain size of 15 μm or less is 70% or more of a sheet thickness of the motor core.

A method of producing a motor core includes preparing a soft magnetic plate containing a transition metal element, preparing a modifying member containing an alloy having a melting point lower than a melting point of the soft magnetic plate, bringing the modifying member into contact with a part of a plate surface of the soft magnetic plate, causing the modifying member to diffuse and penetrate into the soft magnetic plate from a contact surface between the soft magnetic plate and the modifying member and forming a hard magnetic phase-containing part in a part of the soft magnetic plate, and laminating a plurality of soft magnetic plates on each other after the modifying member is brought into contact with the part of the plate surface of the soft magnetic plate.

A laminated core (100) has a plurality of legs having an extension direction in a direction perpendicular to a lamination direction of electrical steel sheets and a plurality of yokes having an extension direction in a direction orthogonal to the lamination direction of the electrical steel sheets and the extension direction of the legs, and, in the same position of the electrical steel sheet in the lamination direction, at least a partial region of the legs and at least a partial region of the yokes are configured by the same electrical steel sheet. The electrical steel sheet is disposed such that a first direction of directions of easy magnetization of the electrical steel sheet is along the extension direction of the legs and a second direction of the directions of easy magnetization of the electrical steel sheet is along the extension direction of the yokes.

An elastic matrix determination method and a vibration analysis method for a laminated iron core, with which it is possible to optimally determine an elastic modulus of a laminated iron core. When a vibration analysis of a laminated iron core obtained by laminating steel sheets is performed by using a configuration expression indicating a relationship between stress and strain in a matrix display by using an elastic matrix, a shear modulus in two surfaces including a laminating direction of the laminated iron core included in the elastic matrix in the configuration expression is determined in consideration of slip between laminated steel sheets.

A non-oriented electrical steel sheet produced by hot-rolling a steel slab containing Si: 2.8 to 6.5 mass % and Zn: 0.0005 to 0.0050 mass % followed by cold rolling and finish annealing, a coating agent containing at least one element from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi is applied to the surface after annealing forming an insulation coating with nitriding-suppressing ability. Alternatively, an intermediate layer containing at least one element from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi and having a nitriding-suppressing ability forms on the steel sheet iron matrix after the annealing and forms an insulation coating, without above elements, on the intermediate layer thus obtaining a non-oriented electrical steel sheet wherein a high strength rotor core with and stator core with excellent magnetic is simultaneously obtained, and a motor core including a stator core and rotor core from the steel sheet.

In a production of a non-oriented electrical steel sheet by hot-rolling a steel slab containing Si: 2.8 to 6.5 mass % and Zn: 0.0005 to 0.0050 mass % followed by cold rolling and finish annealing, a coating agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi is applied to the steel sheet surface after the finish annealing to form an insulation coating with a nitriding-suppressing ability. Alternatively, an intermediate layer containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi and having a nitriding-suppressing ability is formed on the steel sheet iron matrix after the finish annealing and form an insulation coating not containing above elements is formed on the intermediate layer thus to obtain a non-oriented electrical steel sheet from which a rotor core with high strength and stator core with excellent magnetic properties after the stress-relief annealing can be obtained at the same time, and a motor core comprising a stator core and rotor core is produced from the steel sheet.

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 grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes: a linear groove formed in one or both surfaces of the electrical steel sheet in a direction intersecting with a rolling direction; and a linear thermal shock portion formed in the one or both surfaces of the electrical steel sheet in a direction intersecting with the rolling direction. An angle between a longitudinal direction of the groove and a longitudinal direction of the thermal shock portion is 1 to 5°.

A laminated core manufacturing method according to the present invention is a manufacturing method for a laminated core including: a laminated body that is configured by laminating core strips that are made of a magnetic material, the laminated body including: a core back portion; and a tooth portion; and electrically insulating members that are disposed on two side portions of the tooth portion, wherein the laminated core manufacturing method includes a bonding step in which the insulating members are pressed onto each of the side surfaces of the tooth portion of the laminated body so as to integrate the laminated body and also so as to fix the insulating members to the laminated body, by means of at least one of an adhesive and a pressure-sensitive adhesive that is disposed between each of the side surfaces of the tooth portion and the insulating members.

The invention relates to a device (11) and a method for producing transformer cores (12), the device comprising a retaining system (19) having a stacking table (18) for collecting sheets of metal (16) from which a transformer core (12) is constructed and having at least two positioning aids for the sheets, the stacking table forming a positioning surface (26) for the positioning aids and being equipped with the positioning aids, the stacking table and the positioning aids being realized such that a free positioning and a location-independent fastening of the positioning aids within the positioning surface is possible, the device having a positioning system (25) by means of which the positioning aids can be disposed on and/or be removed from the stacking table.

A grain-oriented electrical steel sheet for a stacked transformer core. The steel sheet having a sheet thickness t, where t and an iron loss deterioration ratio obtained by subjecting the steel sheet under elliptic magnetization satisfy the following relations: (i) when t≤0.20 mm, the iron loss deterioration ratio is 85% or less; (ii) when 0.20 mm<t<0.27 mm, the iron loss deterioration ratio is 80% or less; and (iii) when 0.27 mm≤t, the iron loss deterioration ratio is 75% or less. The iron loss deterioration ratio is calculated from ((W.sub.A−W.sub.B)/W.sub.B)×100, where W.sub.A is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 1.0 T in a direction orthogonal to the rolling direction, and W.sub.B is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.