Abstract: There is provided a position control apparatus and method for a table member which is capable of controlling the positioning of the table through very small displacement thereof, to thereby prevent the position of the table from deviating even when a disturbance such as vibration is applied to the table. A table member is movable relative to the base member in a predetermined direction. A threaded shaft is rotatably mounted on a base member and elastically deformable when twisted. A motor is coupled to one end of the threaded shaft, for rotating the threaded shaft to displace the table member. A pressurizing and fixing member is arranged in the vicinity of a location where the motor is coupled to the threaded shaft, for pressurizing the threaded shaft to be fixed in position.

Abstract: A dynamic pressure bearing apparatus having high performance and excellent stability without hindering operations of appliances due to a leaked oil, the dynamic pressure bearing apparatus including: a rotating shaft inclined in a predetermined direction from a vertical direction; a sleeve rotatably supporting the rotating shaft; an operating fluid for generating a dynamic pressure, the operating fluid being filled in a gap formed between the sleeve and the rotating shaft; and a capturing device for capturing the operating fluid leaked from the gap, the capturing device being disposed on an outside surface of the sleeve in the predetermined direction.

Abstract: A motor is provided with a riser member having a base portion fixed to the surface of the commutator of a rotor, a first turned-back portion bent so as to hook the winding of the motor, and a second turned-back portion provided on the side opposite to the base portion with respect to the first turned-back portion. Thereby, a ring varistor can be supported by the second turned-back portion, and the mounting of the ring varistor can be effected easily.

Abstract: The present invention relates to a vibration wave motor which is configured to prevent abnormal noise from being produced at a start time or a stop time and, more particularly, to a control device for a vibration wave motor which obtains a driving force by applying a periodic voltage to an electro-mechanical energy conversion element so as to generate in a vibration member thereof a plurality of standing waves having a phase difference therebetween, the plurality of standing waves being synthesized to generate a driving vibration in the vibration member.

Abstract: A method of forming a stator for a stepping motor, including the steps of forming comb teeth by cutting a flat section of a plate having a cylindrical section around the flat section and bending the comb teeth up to a first angle. Next, the comb teeth are bent up to a second angle larger than the first angle and the thickness of the comb teeth is reduced so as to render uniform the thickness of all the comb teeth. Then, the cylindrical section is subjected to a drawing process at least one time. Finally, the comb teeth are bent up to a right angle. As a result, the occurrence of cambers in the comb teeth is eliminated and the comb teeth are not inclined in the peripheral direction. Also, the accuracy with which the comb teeth are bent to a right angle can be improved thereby.

Abstract: A method for manufacturing a stator of a stepping motor comprises the steps of carrying out a half-pierce and push-back process to a frame plate to make an area in which comb teeth are to be formed and an area to be blanked out readily separable, carrying out a blanking process to separate the blanked out area from the comb teeth, and bending the comb teeth to a predetermined angle and collapsing the comb teeth to make the thicknesses of the comb teeth uniform. The comb teeth are then bent at right angles to an outer periphery of the frame plate.

Abstract: A stepping motor having two stator units axially arranged. Each of the stator units includes an inner yoke and an outer yoke having a plurality of pole teeth circumferentially formed at a predetermined pitch around a rotor having magnetic poles. The outer yoke of one of the stator units is asymmetrically arranged so that the pole teeth thereof are shifted from center between the pole teeth of the inner yoke in a specific direction. As a result, a cogging torque is reduced, constant speed rotation is attained and variations in the output torque are eliminated. Variation in the generated torque are also reduced by controlling the drive pulse width, the drive voltage or the drive current during the driving operation in accordance with the number of excitation phases.

Abstract: A recorder motor with an encoder, for forming an image on a record medium in accordance with image information, has the encoder on the outside of the motor case and a plastic dust-proof cover for the encoder mounted on the case. Thus, contamination by dust or ink mist is prevented, and stable and high precision motor rotation is maintained.

Abstract: A brushless motor includes a rotor having a multipolar magnet with n-number of magnetic poles and a stator yoke having a plurality of field coils disposed at a position opposing the multipolar magnet. The stator yoke of the brushless motor is provided with a magnetic-resistance varying portion to improve the smoothness of rotation of the rotor.

Abstract: On an electric circuit substrate comprising an electric circuit, a radiator plate is placed for heat radiation of an integrated circuit structure and a transistor which emits heat, and the integrated circuit structure and the transistor are placed on the radiator plate and a power supply terminal is integrally provided on the radiator plate.

Abstract: A brushless motor includes a rotor having a multipolar magnet with n-number of magnetic poles and a stator yoke having a plurality of field coils disposed at a position opposing the multipolar magnet. The stator yoke of the brushless motor is provided with a magnetic-resistance varying portion to improve the smoothness of rotation of the rotor.

Abstract: An electric motor which achieves reduced axial height by an arrangement of a motor case which mounts an outer field magnet and which also rotatably supports a motor shaft. A cup shaped yoke fixed to the shaft supports a rotor core and coil. A commutator is mounted on the yoke and is contacted by brushes fixed to a resin member embedded in an aperture formed in the motor case.

Abstract: A motor having a rotary shaft, a coil wound on an iron core fixed to the rotary shaft, a yoke member, a magnetic flux producing member and commutator means has its yoke member constructed with yoke supporting portions serving as a magnetic path of magnetic flux and four magnetic poles having substantially arcuate shape. Each magnetic pole has a largest dimension of thickness at a center portion thereof and extends outwardly with gradually reduced thickness in accordance with the distance from the central portion. Ends of each magnetic pole respectively oppose corresponding ends of the adjacent magnetic poles with a slight distance therebetween, with the magnetic poles surrounding an outer periphery of the iron core. The magnetic flux producing member includes two rectangular parallelepiped blocks.

Abstract: A speed reducer in which a shaft for supporting a plurality of pinion gears is provided on the closed end of a cylindrical gear mounting plate having one end closed, a reduction gear in meshing engagement with the pinion gear is contained in the cylindrical gear mounting plate, a single stage speed reducing unit is constituted by the gear mounting plate, the pinion gear and the reduction gear, and the gear mounting plates of the respective stages are closely joined together, and the cylindrical inner peripheral surface of the gear mounting plate is formed with ribs for intercepting sounds produced by the meshing engagement between the gears.

Abstract: A lens drive device of the invention is disclosed comprising a motor drive for each lens of zoom means and focusing means, whereby a motor is made to have a concentric layer structure about a photographic optical axis, and a single magnetic circuit for the motor having the aforesaid layer structure is formed by a single permanent magnet.

Abstract: A motor in which a coil constituting a rotor is integrally formed with self-lubricating resin or oil-containing resin to construct a portion of a bearing, which is utilized as a part of a roller or sliding bearing.

Abstract: A bearing member of a ring-shaped lubrication member made of a resin material is arranged between a ring-shaped stator having an excitation coil and pole teeth and a ring-shaped magnet rotor arranged inside of the stator, and the stator, magnet rotor and the lubrication member are held in union by holding members to form a motor.

Abstract: The present invention relates to a rotary electric machine of the type in which a coreless rotary coil having an end connection only at its one side end is mounted on a shaft rotatably within the magnetic field of a stator field magnet and is directed to a novel design for making such type of rotary electric machine flattened in form. According to the present invention a flat shaped coreless electric machine is provided by arranging the commutator of the rotary machine within an open side part opposed to the end connection of the coreless rotary coil.

Abstract: A coreless rotary electric appliance comprising a rotary coil of a cup-shaped coil body open at an end face thereof which is composed of inclined coil wire portions wound with a determined angle along the cylindrical periphery of said coil body and of end connecting wire portions arranged on one end face of said coil body to connect said coil wire portions in succession whereby said coil body being formed by a continuous wire composed of said coil wire portions connected in succession by said end connecting portions, whereby said coil body being featured by an asymmetrical structure that two coil wire portions connected to both ends of each end connecting wire portion and wound along the cylindrical periphery of said coil body are provided with different inclination angles with respect to the generatrix of said cylindrical surface of the coil body.

Abstract: The present invention relates to a miniature rotary electric machine and more particularly to a coreless type of rotary electric machine. The coreless rotary electric machine includes a rotor coil formed as a coil body in a form of cup with its one end being open. The coil body has, on its circumference, a coil part wound with a predetermined inclination. An end connection wire part is provided to make a connection between adjacent windings only at the one side end of the inclined coil part so that each two adjacent windings of the inclined coil part are connected each other successively by the end connection wire part. According to a feature of the present invention, the inclined coil part and the end connection wire part are formed by coil assembly portions each comprising a plural number of groups of windings turned at the same position in layers with the same number of turns. The coil assembly portions form together a coil assembly of large winding capacity.