Abstract: An electric motor includes a stator and a rotor including a permanent magnet and an electromagnetic steel sheet. The electromagnetic steel sheet includes a magnet insertion hole, a first outer peripheral surface including an inter-pole part of the rotor, a second outer peripheral surface including a magnetic pole center part of the rotor, a first slit elongated in a circumferential direction of the rotor, and a first portion formed between the first slit and the magnet insertion hole. A distance from the first outer peripheral surface to the stator is larger than a distance from the second outer peripheral surface to the stator. The electric motor satisfies ?a<?b, where ?a is a first angle formed by a first line and a second line and ?b is a second angle formed by a third line and the second line.

Abstract: A motor including a rotor, and a stator having a plurality of coils wound around slots, wherein at least any one of the coils includes a single aluminum wire, a single copper wire joined to the aluminum wire, a stranded wire (lead wire) joined to the copper wire, a cold-pressure-welded joint portion (joint portion) joined between the aluminum wire and the copper wire by cold pressure welding, and a non-pressure welded joint portion (joint portion) provided between the copper wire and the stranded wire (lead wire). A burr covered by an insulation member (insulation tube) is provided in the cold-pressure-welded joint portion (joint portion). A thickness of the insulation member (insulation tube) is larger than a height of the burr.

Abstract: A rotor is connected to a shaft member and rotates about a central axis. The rotor includes a shaft hole having at least part of the shaft member disposed therein; and flow paths disposed around the shaft member and penetrating the rotor in a direction parallel with the central axis. Each flow path has a first surface facing outward in the radial direction; a second surface disposed outward of the first surface in the radial direction and facing the first surface; a third surface connecting the first and second surfaces at one end in a rotational direction about the central axis; a fourth surface connecting the first and second surfaces at the other end in the rotational direction. The condition C<D is satisfied, where C is the distance between both ends of the first surface, and D is the distance between both ends of the second surface.

Abstract: A rotor includes a rotor core, a permanent magnet, a first part, a second part, and a third part. The third part is formed integrally with the first part and the second part. The rotor core is longer than the permanent magnet in an axial direction.

Abstract: An electric motor includes a rotor and a stator. The rotor includes a rotor core and a plurality of permanent magnets fixed to an outer surface of the rotor core. The stator includes a stator core including a tooth part and a winding wound around the stator core. The electric motor satisfies an expression of 1<t2/t1?8 where t1 is a minimum distance from a center of a front end surface of the tooth part to one permanent magnet of the plurality of permanent magnets and t2 is a distance from an end of the tooth part to the one permanent magnet.

Abstract: A hot-water supply system heats up water by power generated by power generation means. The hot water supply system includes a compressor and a water heat-up unit. In the hot-water supply system, the compressor compresses refrigerant and circulates the refrigerant through a refrigerant circuit. The water heat-up unit heats up water by changing, in accordance with the generated power, a rotation rate of an electric motor for driving the compressor.

Abstract: A rotor includes an electromagnetic steel sheet and a permanent magnet. The electromagnetic steel sheet includes a magnet insertion hole, a slit, a first end part, a second end part, a third end part, a fourth end part, and a fifth end part. Expressions of L1>L2 and L3?L2 are satisfied, where L1 is a distance from the first end part to the magnet insertion hole, L2 is a distance from a first boundary between the first end part and the second end part to the magnet insertion hole, and L3 is a distance from a second boundary between the second end part and the third end part to the magnet insertion hole.

Abstract: A rotor includes a first permanent magnet, a second permanent magnet, and an electromagnetic steel sheet. The electromagnetic steel sheet includes a magnet insertion hole, a projection, a first end part, a second end part (211b), a third end part, and a fourth end part. The rotor satisfies an expression of t?2×w×sin(R/2)?2×t, where t is a thickness of the electromagnetic steel sheet, R is an angle formed by the third end part and the fourth end part, and w is a distance from an intersection point of a straight line including the first end part and a straight line including the third end part to an intersection point of a straight line including the third end part and a straight line including the fourth end part.

Abstract: A rotary electric machine includes a rotor core that rotates about a rotation axis, a plurality of first magnets disposed in a circumferential direction of the rotor core and embedded in the rotor core, a second magnet that includes a plurality of magnetic poles disposed in the circumferential direction of the rotor core and is disposed on an end surface of the rotor core in an extending direction of the axis, the second magnet being disposed at a position in a direction orthogonal to the axis, different from positions at which the plurality of first magnets are disposed, and a stator provided on an outer side of the rotor core in the direction orthogonal to the rotation axis.

Abstract: A rotor includes a rotor core having a magnet insertion hole and a permanent magnet provided in the magnet insertion hole. The rotor core has a slit on an outer side of the magnet insertion hole in a radial direction of the rotor core. The permanent magnet is magnetized by placing the rotor so as to face a tooth around which a winding is wound, rotating the rotor in a first rotating direction from a rotational position where a center of the magnet insertion hole in a circumferential direction of the rotor core faces a middle portion between both ends of the winding in the circumferential direction and supplying electric current to the winding, and rotating the rotor in a second rotating direction opposite to the first rotating direction from the rotational position and supplying electric current to the winding.

Abstract: A permanent-magnet synchronous motor includes: an annular stator core; a cylindrical rotor disposed inside the stator core, and having a first end face in an axial direction of the stator core and a second end face in the axial direction; a disk-shaped sensor magnet having a plurality of magnetic poles disposed circumferentially, and having a third end face and a fourth end face; and a magnetic sensor disposed so as to be opposed to the fourth end face in the axial direction, and detecting a rotating position of the sensor magnet. When a first thickness means the axial thickness at the center of each of the magnetic poles and a second thickness means the axial thickness of an inter-magnetic-pole portion between adjacent magnetic poles of the magnetic poles, the second thickness is greater than the first thickness.

Abstract: A sensor magnet includes: a first magnetic-pole part including a magnetic pole of first polarity; a second magnetic-pole part including a magnetic pole of second polarity; and an inter-pole part formed between the first magnetic-pole part and the second magnetic-pole part. A width of the inter-pole part is larger than both of a width of the first magnetic-pole part and a width of the second magnetic-pole part.

Abstract: A magnetizing method includes the steps of preparing a rotor comprising a rotor core having a magnet insertion hole and a permanent magnet provided in the magnet insertion hole, placing the rotor so as to face a tooth around which a winding is wound, rotating the rotor in a first rotating direction by a first angle ?1 from a rotational position where a center of the magnet insertion hole in a circumferential direction of the rotor core faces a middle portion between both ends of the winding in the circumferential direction and supplying electric current to the winding, and rotating the rotor in a second rotating direction opposite to the first rotating direction by a second angle ?2 from the rotational position direction and supplying electric current to the winding. The second angle ?2 is smaller than the first angle ?1.

Abstract: A switched capacitor amplifier circuit includes an operational amplifier, a first capacitor and a second capacitor each having one end connected to a negative input terminal of the operational amplifier, a first switching circuit configured to connect the other end of the first capacitor and a signal source during a first operation, a second switching circuit configured to connect the other end of the second capacitor and the output terminal of the operational amplifier so as to connect the output terminal and the negative input terminal of the operational amplifier through the second capacitor during the second operation, and an impedance converter circuit configured to convert an output impedance of the signal source into a specified impedance, the impedance converter circuit being connected between the first switching circuit and the other end of the first capacitor.

Abstract: An electric motor includes a stator and a consequent-pole-type rotor including an annular rotor core disposed on an inner side of the stator and a plurality of permanent magnets disposed inside the rotor core and arrayed in a circumferential direction of the rotor core. The rotor core includes at least one slit provided inside the rotor core and disposed on an outer side of each of the permanent magnets in a radial direction of the rotor core, and at least one slit provided on an outer circumferential surface of the rotor core and disposed between the permanent magnets adjacent to each other.

Abstract: A motor rotor includes: a shaft; a smaller-radius iron core fixedly attached to an outer peripheral surface of the shaft; a larger-radius iron core disposed spaced apart from the smaller-radius iron core in a radial direction perpendicular to an axis of the shaft, which is formed in a ring shape in cross section by a combination of a plurality of iron core blocks, and disposed to share a common axis with the smaller-radius iron core; and an insulating resin portion used to fix the smaller-radius iron core and the larger-radius iron core. The larger-radius iron core and the smaller-radius iron core are formed of their respective different materials. The material forming the larger-radius iron core has an iron loss less than an iron loss of the material forming the smaller-radius iron core.

Abstract: An interior permanent magnet motor includes: a rotator; a stator; a permanent magnet inserted into a magnet accommodating hole; and a slit formed on a radially outer side of the magnet accommodating hole. A space portion is ensured between a radially outer surface of the permanent magnet and a rotator core in each region opposed to the slit. The permanent magnet is apart from the rotator core via the space portion in the each region opposed to the slit.

Abstract: A permanent magnet embedded electric motor includes a slit and a flux barrier. A hole defining portion of a magnet insertion hole includes an extended portion. The extended portion projects toward an interpolar core portion in a rotor core in an area positioned further on an outer side of a circumferential direction with respect to a width-direction end surface of a permanent magnet. (Lb) is larger than (La), and (Lc) is smaller than (Ld), where the (La) represents a distance between the slit and the core outer peripheral surface; the (Lb) represents a distance between the slit and an outer peripheral-side surface of the permanent magnet; the (Lc) represents a shortest distance between the extended portion and the interpolar core portion; and the (Ld) represents a thickness of the permanent magnet.

Abstract: A permanent-magnet-embedded electric motor includes a stator core including a yoke and a plurality of teeth, a rotor core including a plurality of magnet insertion holes, and a plurality of permanent magnets respectively inserted into the magnet insertion holes, each being arranged with a lateral direction set in a radial direction of the rotor core and with a longitudinal direction set in a direction orthogonal to the radial direction. When a width of base sections of the teeth is represented as S1, a width of a distal end sections of the teeth is represented as S2, a width of the permanent magnets in the longitudinal direction is represented as R1, and a width of the magnet insertion holes in an extension direction thereof is represented as R2, relations of S1?R1<S2 and S1?R2?R1 are satisfied.

Abstract: A rotor of a permanent-magnet embedded motor includes a rotor core having magnet insertion holes along a circumferential direction and a magnet inserted into each of the holes, wherein a gap is formed at opposite ends of a hole at a time of inserting the magnet therein, an outer peripheral face of the core is formed by a first curved surface formed from a magnetic pole center to between poles, with a radial distance from a shaft center of the core being largest at the pole center on the peripheral face, and a second curved surface formed from an interpolar portion toward the pole center to intersect with the first curved surface, with the radial distance from the shaft center being smallest in the interpolar portion on the peripheral face, and wherein a length of the first curved surface is larger than a length of the second curved surface.