Abstract: An electric motor includes a rotor having a field permanent magnet, a board housing member fixed to a stator, and a magnetism detecting circuit that detects the magnetism of the field permanent magnet. The magnetism detecting circuit includes a circuit board that is discrete from the board housing member, a sensor case that is discrete from the circuit board and is supported on the circuit board, and a rotation sensor held by the sensor case. The board housing member has an engagement hole and a positioning surface. The sensor case has an engagement convexity corresponding to the engagement hole and an abutting surface corresponding to the positioning surface. When the circuit board has been located in the board housing member, the engagement convexity engages the engagement hole and the abutting surface abuts the positioning surface, resulting in that the rotation sensor is positioned relative to the board housing member.

Abstract: A washing machine has a water tank and a motor for rotationally driving a load received in the water tank and performs a washing operation including a washing process, a rinsing process, and dewatering process. The motor has a stator and a rotor. The stator has a stator coil, and the rotor has a rotor magnet including a first magnet and a second magnet. The first magnet has a permanent magnet having a high coercive force, and the second magnet has a permanent magnet having a lower coercive force than the first magnet and generating easily changeable magnetic flux. In the washing process of the washing operation, the second magnet is magnetized so that the magnetic flux of the rotor magnet acting on the stator increases, and in the dewatering process, the second magnet is magnetized so that the magnetic flux acting on the stator decreases from the level in the washing process.

Abstract: A rotor core of a rotating electrical machine formed by stacking a plurality of blanks blanked from a steel sheet, the blank having a yoke, a magnetic pole portion confronting the yoke, and a magnet insertion hole positioned between the yoke and the magnetic pole portion, the magnetic pole portion having a projection projecting circumferentially at two circumferential sides thereof.

Abstract: A rotor for an electric motor includes a rotor core formed by axially stacking a plurality of magnetic steel plates and a plurality of axially extending magnet insertion holes, and a magnetic sensor provided on the stator so as to be opposed to an axial end face of the rotor, a positioning steel plate provided on one of both axial ends of the rotor core opposed to the magnetic sensor and having an opening corresponding to the magnetic insertion holes, and a protrusion which is provided on at least one of paired circumferentially extending sides of the opening so as to protrude inside the opening.

Abstract: A rotor for an electric motor includes a base plate (13) made of a magnetic material and coupled to a rotational shaft (12), a rotor core (18) provided on the base plate (13) and including a protrusion protruding axially relative to the base plate and the teeth of the stator, the rotor core having an outer peripheral face and an axial end, a plurality of magnet insertion portions defined in the rotor core, a plurality of rotor magnets provided in the magnet insertion portions respectively, each magnet having a stator side and a counter-stator side both magnetized so as to have poles differing from each other, and a position sensor detecting a rotational position of the rotor core and disposed radially or axially opposite the outer peripheral face or the axial end of the rotor core so as to correspond to the protrusion of the rotor core.

Abstract: An electric motor (1) including a stator (2), a rotor (3) having a field permanent magnet (6), a terminal block (21) fixed on the stator, and a magnetism detecting circuit for detecting magnetism of the field permanent magnet thereby to detect a rotational position of the rotor. The magnetism detecting circuit includes a circuit board (22) arranged on the terminal block, and a rotation sensor (30) mounted on the circuit board such that it is mounted in a sensor case (33). The sensor case (33) is so constituted as to position the rotation sensor (30) on he terminal block when the circuit board (22) is arranged on the terminal block.

Abstract: A rotor for a permanent magnet motor of an outer rotor type having a plurality of permanent magnets and disposed around a stator includes a frame, an annular iron core combined integrally with the frame, and a plurality of insertion holes formed in the core so that the permanent magnets are inserted in the insertion holes respectively. The frame, the core and the permanent magnets are combined integrally with one another by a synthetic resin. Each insertion hole includes a magnet disposing portion in which the permanent magnet is disposed, a space portion located in at least one of circumferential both ends of each permanent magnet disposed in the magnet disposing portion, and a positioning portion positioning each permanent magnet in the magnet disposing portion, and the molten synthetic resin is poured into the space portion.

Abstract: A rotor for an electric motor includes a base plate (13) made of a magnetic material and coupled to a rotational shaft (12), a rotor core (18) provided on the base plate (13) and including a protrusion protruding axially relative to the base plate and the teeth of the stator, the rotor core having an outer peripheral face and an axial end, a plurality of magnet insertion portions defined in the rotor core, a plurality of rotor magnets provided in the magnet insertion portions respectively, each magnet having a stator side and a counter-stator side both magnetized so as to have poles differing from each other, and a position sensor detecting a rotational position of the rotor core and disposed radially or axially opposite the outer peripheral face or the axial end of the rotor core so as to correspond to the protrusion of the rotor core.

Abstract: A rotor for a permanent magnet motor of the outer rotor type is disclosed. The rotor has a plurality of permanent magnets and is disposed around an outer circumference of a stator. The rotor includes a frame, an annular iron core combined integrally with the frame, and a plurality of insertion holes formed in the core so that the permanent magnets are inserted in the insertion holes.

Abstract: A rotor for an electric motor includes a frame previously formed and fixed to a rotational shaft of the motor so as to be rotated with the rotational shaft, and a magnet molded from a molten magnetic resin so as to be disposed at a stator side of the frame and so as to be integrated with the frame.

Abstract: A molded core for an electric motor includes a resin cover formed by placing a stator core in a cavity of a molding die and injecting a molten insulating resin into the cavity of the molding die so that the resin cover is formed on an outer surface of the stator core by means of molding. The molded core includes a generally annular yoke, a plurality of teeth radially extending from the yoke, the yoke and the teeth constituting the stator core, and a plurality of distal end resin cover portions included in the resin cover and covering distal end faces of the teeth respectively, the distal end resin cover portions having different radial dimensions.

Abstract: A rotor for an electric motor includes a frame previously formed and fixed to a rotational shaft of the motor so as to be rotated with the rotational shaft, and a magnet molded from a molten magnetic resin so as to be disposed at a stator side of the frame and so as to be integrated with the frame.

Abstract: A method of making a rotor for an electric motor includes accommodating, in a forming mold, a plurality of annularly disposed rotor magnets, a frame made of steel plate and formed generally into a shape of a cup, the frame having an annular wall disposed outside the annularly disposed rotor magnets so as to be located at a side opposed to a stator with respect to the rotor magnets, the annular wall having a open end, and a ring member made of a magnet material and disposed along the annular wall of the frame at an inner or outer circumferential side of the annular wall, the rotor magnets being held by magnet holding means provided in the forming mold in execution of the accommodating step, and pouring a molten resin into the forming mold accommodating the rotor magnets, the frame and the ring member and hardening the resin.

Abstract: A rotor for an electric motor includes a plurality of annularly disposed rotor magnets, a frame made of a steel plate and having an annular wall disposed outside the annularly disposed rotor magnets so as to be located at a side opposed to the stator with respect to the rotor magnets, the annular wall having an open end, a ring member made of a magnetic material and disposed along the annular wall of the frame at an inner or outer circumferential side of the annular wall, and a resin molded member comprising a resin for integrating the rotor magnets, the frame and the ring member together.

Abstract: A molded stator core for an electric motor includes a stator core including a yoke and a plurality of teeth formed on an outer periphery of the yoke, the teeth having different types, and a covering member covering substantially the overall stator core and molded from an insulating resin by pouring the resin through a plurality of gates disposed so as to correspond to the yoke. In the molded stator core, an amount of resin axially flowing from each gate to the corresponding tooth of a first type is approximated to an amount of resin axially flowing from each gate to the corresponding tooth of a second type.

Abstract: A rotor for an electric motor includes a frame made of a resin and having a cylindrical yoke mounting portion, a base covering one end side of the yoke mounting portion, and a shaft supporting portion located at the center of rotation of the base, all of which are formed integrally with the frame, a rotor yoke mounted on the yoke mounting portion and substantially divided into a plurality of unit yokes, and a plurality of rotor magnets mounted on the yoke mounting portion along the rotor yoke.

Abstract: A method of making a squirrel-cage rotor employs a forging die assembly including a receiving die receiving one end of a rotor core and having a first annular concavity corresponding to one of two end rings and a pressing die movable relative to the other end of the rotor core to form a second annular concavity corresponding to the other end ring. The one end of the rotor core is set in the receiving die, and a forging material such as aluminum is set at the other end of the rotor core. Subsequently, the pressing die is moved relative to the other end of the rotor core so that the forging material is pressurized to be plastically deformed. The forging material is caused to enter the first concavity through slots of the rotor core. Consequently, the first and second concavities and the slots of the rotor core are filled by the forging material such that a squirrel-cage conductor is formed.

Abstract: A rotor for an electric motor includes a plurality of annularly disposed rotor magnets, a frame made of a steel plate and having an annular wall disposed outside the annularly disposed rotor magnets so as to be located at a side opposed to the stator with respect to the rotor magnets, the annular wall having an open end, a ring member made of a magnetic material and disposed along the annular wall of the frame at an inner or outer circumferential side of the annular wall, and a resin molded member comprising a resin for integrating the rotor magnets, the frame and the ring member together.

Abstract: In an electrophotographic process in which an electrostatic latent image formed on the surface of a photosensitive member according to conventional electrophotography is transferred onto a latent image receptor sheet and the transferred latent image converted into a visual image with a developer, the improvement that when the receptor sheet is brought into contact with the photosensitive member to transfer the latent image from it onto the sheet, a bias voltage containing a high frequency component is applied across the member and the sheet facilitating a positive and uniform transfer to improve the continuous tone quality of the resulting image.

Abstract: An overcoated photoconductive material is uniformly illuminated in the presence of an electric field to create persistent internal polarization. Minute, translucent toner particles are then applied onto the surface of the photoconductive member, and a colored light image is projected onto the surface of the photoconductive member through the toner particles. Equal numbers of the toner particles are colored in three primary colors respectively to form a tri-color mosaic pattern on the surface of the photoconductive member. Each particle absorbs light of its complementary color during the imaging step so that the internal polarization is dissipated in a pattern corresponding to a colored positive of the light image as quantized by the colored mosaic of toner particles. The particles which absorbed light, constituting a colored negative of the light image, are then selectively frictionally removed from the surface of the photoconductive member since the charge holding them to the surface is weak.