Abstract: An electric motor includes: a permanent magnet; a rotor including a first rotor core having a first electrical steel sheet and a second rotor core having a second electrical steel sheet; and a stator including a stator core. The first electrical steel sheet is located outside the stator core. A relationship among a minimum width BL1 of a first left bridge, a thickness tL1 of the first left bridge, a minimum width BR1 of a first right bridge, a thickness tR1 of the first right bridge, a minimum width BL2 of a second left bridge, a thickness tL2 of the second left bridge, a minimum width BR2 of a second right bridge, and a thickness tR2 of the second right bridge satisfies (BL1×tL1+BR1×tR1)>(BL2×tL2+BR2×tR2).

Abstract: A rotor has a rotor core having a magnet insertion hole and a permanent magnet inserted therein. The rotor core has a flux barrier. When a straight line in the radial direction passing through a center of the magnet insertion hole in the circumferential direction is defined as a pole center line, a distance W from the pole center line to the flux barrier is shorter than a distance M from the pole center line to an end of the permanent magnet in the circumferential direction. A width A in the radial direction of a bridge formed between the flux barrier and an outer circumference of the rotor core, a width B of the flux barrier in the radial direction, a width C of the magnet insertion hole in a thickness direction of the permanent magnet, and a gap G between the rotor and a stator satisfy A<G<B<C.

Abstract: A motor includes a stator core having an annular shape about an axis, a coil wound on the stator core, and a rotor core disposed on an inner side of the stator core in a radial direction about the axis. The rotor core has a stacked body in which a plurality of steel laminations are stacked in a direction of the axis, and a magnet insertion hole famed in the stacked body. The rotor core has a length in the direction of the axis longer than that of the stator core. A magnet is inserted in the magnet insertion hole. The rotor core has a first region where the magnet is inserted in the magnet insertion hole and a second region where the magnet is not inserted in the magnet insertion hole, in the direction of the axis. At least one steel lamination in the second region of the rotor core has an opening area smaller than an opening area of each steel lamination in the first region of the rotor core.

Abstract: An electric motor includes: a stator including a first stator core, a second stator core, and a slot in which a stator winding is disposed, and a rotor including a first rotor core facing a first stator core in a radial direction and a second stator core facing the second stator core in the radial direction. The first stator core and the second stator core are laminated in an axial direction. The stator includes a depression formed in a position facing the slot and not touching the stator winding. A volume of the first rotor core is smaller than a volume of the second rotor core.

Abstract: A driving device drives a motor including a rotor having a neodymium rare earth magnet. The driving device includes an inverter, a first detector that outputs a first detection signal corresponding to a motor driving current supplied to the motor, a protection level setting unit that sets an overcurrent protection level, a second detector that outputs a second detection signal corresponding to a driving state of the motor, and a control device. The control device executes first control of lowering the motor driving current immediately after the motor driving current corresponding to the first detection signal exceeds the overcurrent protection level. When the protection level setting unit lowers the overcurrent protection level to a new current level based on the second detection signal, the control device executes second control of lowering the motor driving current to a level lower than the new current level.

Abstract: A rotor core has a magnet insertion hole, an opening formed adjacent to the magnet insertion hole in the circumferential direction, and a thin wall portion formed between the opening and an outer circumference of the rotor core. A stator core has a length in the axial direction shorter than that of the rotor core. The rotor core has a facing region where the rotor core faces the stator core in the radial direction and an overhang region where the rotor core protrudes from the stator core in the axial direction. A distance from the center axis to a portion of the outer circumference located on a radially outer side of the magnet insertion hole is longer in at least part of the overhang region than in the facing region. The minimum width of the thin wall portion in the radial direction is the same in both regions.

Abstract: A rotor includes a first rotor core, a plurality of permanent magnets, a plurality of second rotor cores, and a first resin part. Each of the plurality of permanent magnets has a first surface in contact with a first radial-direction-outward-facing surface of the first rotor core and a second surface facing outward in a radial direction. Each of the plurality of second rotor cores has a surface facing inward in the radial direction. The surface of each of the plurality of second rotor cores facing inward in the radial direction is in contact with the second surface of corresponding one of the plurality of permanent magnets. The first resin part is provided between adjoining second rotor cores among the plurality of second rotor cores.

Abstract: A rotor core has steel laminations stacked in the axial direction, and a permanent magnet is embedded in the rotor core. A stator core has steel laminations stacked in the axial direction, and a coil is wound on the stator core. The stator core has a slot for housing the coil. The stator core has a first core portion at an end portion in the axial direction and a second core portion at a center portion in the axial direction. An area of the slot is larger in the first core portion than in the second core portion. A sheet thickness T0 and a lamination gap L0 of the steel laminations of the rotor core and a sheet thickness T1 and a lamination gap L1 of the steel laminations of the first core portion of the stator core satisfy at least one of 0.05 mm?T0?T1?0.15 mm and L0<L1.

Abstract: A motor includes a rotor having a rotor core having an annular shape about an axis and famed of a first core sheet subjected to press processing, and a permanent magnet embedded in the rotor core, and a stator surrounding the rotor from outside in a radial direction about the axis. The stator has a stator core famed of a second core sheet subjected to press processing. The thickness of the first core sheet is thicker than the thickness of the second core sheet. The first core sheet has an outer circumference, a magnet insertion hole in which the permanent magnet is inserted, and a bridge portion between the outer circumference and the magnet insertion hole. The minimum width of the bridge portion in the radial direction is smaller than the thickness of the first core sheet.

Abstract: A stator includes a stator core having a yoke and a tooth, an insulator provided on the tooth, and a coil wound around the tooth via the insulator. The yoke has a first hole provided in an end surface in an axial direction of the stator core. The tooth has a second hole provided in the end surface. The second hole is provided at the center of the tooth in a circumferential direction of the stator core and arranged on a straight line passing through the first hole and extending in a radial direction of the stator core. The insulator has a first convex portion fitting into the first hole and a second convex portion fitting into the second hole.

Abstract: A rotor includes a rotor core having an outer circumference extending in a circumferential direction about an axis and a magnet insertion hole located on an inner side of the outer circumference in a radial direction about the axis, and a permanent magnet inserted in the magnet insertion hole. The rotor core has a flux barrier at an end of the magnet insertion hole in the circumferential direction. At least a part of the flux barrier is located on the outer circumference side of a magnetic pole face of the permanent magnet. In the rotor core, an inter-pole portion is defined on an outer side of the magnet insertion hole in the circumferential direction. A groove portion is formed on the inter-pole portion side of the flux barrier in the circumferential direction. The groove portion is recessed inward in the radial direction from the outer circumference. The groove portion faces the flux barriers in the circumferential direction.

Abstract: A driving device is used with a compressor including a motor including coils. The driving device drives the motor. The driving device includes an inverter connected to the coils, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state, a controller to control the inverter and the connection switching unit, and a compressor state detection unit to detect a state of the compressor. When the connection state of the coils is the first connection state, the controller controls the motor based on a first detection value detected by the compressor state detection unit and a first threshold. When the connection state of the coils is the second connection state, the controller controls the motor based on a second detection value detected by the compressor state detection unit and a second threshold.

Abstract: A rotor includes a rotary shaft extending in an axial direction, a first rotor core, a permanent magnet, and a second rotor core. The first rotor core includes a first core part and a second core part arranged in the axial direction and is supported by the rotary shaft. The permanent magnet is attached to the first rotor core. The second rotor core is arranged between the first core part and the second core part. The area of a part where the second rotor core exists is larger than the area of a part where the first rotor core exists when viewed in the axial direction.

Abstract: A rotor includes a rotor core having a magnet insertion hole and having an annular shape about an axis, and a permanent magnet of a flat plate shape disposed in the magnet insertion hole and having a thickness and a width in a plane perpendicular to the axis. The thickness of the permanent magnet defines a thickness direction, and the width of the permanent magnet defines a widthwise direction. The magnet insertion hole has a portion inclined relative to the widthwise direction so that an opening dimension T1 in the thickness direction at an end of the magnet insertion hole in the widthwise direction is smaller than an opening dimension T2 in the thickness direction at a position distanced from the end by the width of the permanent magnet.

Abstract: A rotor core includes a magnet insertion hole in which a magnet is disposed and an opening connected to the magnet insertion hole. The opening has an outer end edge and an inner end edge facing each other. The opening has a first portion where the outer and inner end edges face each other across a width W1, and a second portion where the outer and inner end edges face each other across a width W2 wider than the width W1. The second portion is located between the first portion and the permanent magnet. A reference line is defined as a straight line obtained by extending a magnetic pole surface of the permanent magnet on a radially outer side a plane perpendicular to the axis. At least a part of the first portion is located on an outer side in the radial direction with respect to the reference line.

Abstract: A refrigerating cycle device includes a compressor, a motor, and a wiring switch part. The compressor compresses a refrigerant. The motor generates power for compressing the refrigerant by rotating a rotor with voltage applied to a plurality of wirings. The motor is disposed in the compressor. The wiring switch part switches between a plurality of wiring states by changing connection between the plurality of wirings. When a rotational speed of the rotor exceeds a predetermined value, the wiring switch part switches to a first wiring state of the plurality of wiring states. The first wiring state differs from a second wiring state of the plurality of wiring state. Efficiency of the second wiring state is highest at the rotational speed.

Abstract: A driving device includes an inverter to output a voltage to coils, a connection switching unit to switch a connection state of the coils between a Y connection and a delta connection, and a controller. The controller causes the inverter to stop outputting, when the connection state of the coils is the Y connection and a current value of the inverter reaches a first threshold A, or when the connection state of the coils is the delta connection and the current value of the inverter reaches a second threshold B. The first threshold A and the second threshold B satisfy B<?3×A.

Abstract: A stator includes a yoke portion, and a tooth portion located inside the yoke portion in a radial direction. A fracture surface ratio of an inner surface of the tooth portion in the radial direction is lower than a fracture surface ratio of a side surface of the yoke portion.

Abstract: Two types of insulating members, i.e., end surface insulators and slot insulators are provided. On tooth portion sides of both side surfaces in the circumferential direction of tooth end surface covering portions of the end surface insulator, first cutouts recessed in the circumferential direction are provided so as to extend in the radial direction. A part axially upward of the first cutouts protrudes in the circumferential direction to form a first overhang portion, and the slot insulator is accommodated between the first overhang portions of two end surface insulators.

Abstract: An electric motor includes: a permanent magnet; a rotor including a first rotor core having a first electrical steel sheet and a second rotor core having a second electrical steel sheet; and a stator including a stator core. The first electrical steel sheet is located outside the stator core. A relationship among a minimum width BL1 of a first left bridge, a thickness tL1 of the first left bridge, a minimum width BR1 of a first right bridge, a thickness tR1 of the first right bridge, a minimum width BL2 of a second left bridge, a thickness tL2 of the second left bridge, a minimum width BR2 of a second right bridge, and a thickness tR2 of the second right bridge satisfies (BL1×tL1+BR1×tR1)>(BL2×tL2+BR2×tR2).