Abstract: A miniature motor with a frequency generator comprising a motor portion having a stator with a permanent magnet for forming a magnetic field and a rotor with rotor windings wound on a rotor core; electric current being fed to the rotor windings via a commutator making sliding contact with brushes, and a frequency generator for detecting the revolution of the motor, in which the frequency generator comprises a frequency generator rotor, mounted on the motor rotor, having a disc-like rotor portion made of a soft magnetic material and equipped with a plurality of magnetic-pole teeth on the outer periphery thereof, an internal-gear core of an annular disc shape, made of a soft magnetic material, disposed in such a manner as to come in contact with the inside of a motor housing and face the outer circumferential surface of the rotor portion and equipped with a plurality of magnetic-pole teeth on the inner periphery thereof, a permanent magnet forming a magnetic field between the magnetic-pole teeth of the rotor po

Abstract: A miniature motor having a positive-coefficient thermistor in which a first supporting member made of an electrically conductive material and electrically connected to at least any one of a pair of brushes housed in a motor cover plate, and a second supporting member made of an electrically conductive material and electrically connected to an external terminal are provided; a positive-coefficient thermistor being supported between the first and second supporting members.This construction makes the assembly of the motor easy, leading to improved productivity, and allows the motor to have a positive overheat preventing function without adding to the number of parts.

Abstract: A miniature motor having a positive temperature coefficient thermistor comprising a stator having a permanent magnet serving as a field, a rotor formed by winding a plurality of rotor windings on a rotor core, brushes supported by a motor cover plate for feeding current to the rotor windings by making contact with a commutator, positive temperature coefficient thermistor for controlling current to the rotor windings, in which the positive temperature coefficient thermistor has one pole on one pole surface thereof, and a plurality of independent split poles corresponding to the rotor windings on the other pole surface thereof, and is fitted to an end face of the rotor core;the rotor windings being connected to the split poles of the positive-coefficient thermistor in such a manner as to be connected in series with the split poles of the positive-coefficient thermistor.

Abstract: A miniature motor comprising a motor case having a bearing on the closed end face thereof, a stator consisting of a permanent magnet, brushes and terminals; and a rotor fixedly fitted to a motor shaft in the motor case and having core windings and a commutator; the rotor being rotatably supported by the bearing; in which the rotor and the stator are adapted so that the balance of magnetic field intensity between the stator and the rotor becomes unbalanced structurally or magnetically, thereby causing the rotor to be biased within the bearing in a predetermined positional direction with respect to the stator.

Abstract: A miniature motor comprising a stator having permanent magnets constituting a two-pole field, and a rotor having rotor windings wound on a rotor core of a three-pole construction, in which the rotor core is formed in such a manner that the cross-sectional shape of the rotor core normal to the motor shaft is made symmetrical with respect to the radial center line of each pole thereof and that the gap between the permanent magnets and a predetermined range from the center line of the arc-shaped outer periphery of the rotor core facing the permanent magnet is made larger than the gap between the permanent magnet and at least part of the other range of the outer periphery of the rotor core.

Abstract: A miniature motor having a motor case comprising a motor housing, fitted with a permanent magnet field and having an opening at one end thereof; an insulating brush base, made of a synthetic resin, fitted to the opening of the motor housing for holding brushgear; and a cover plate, made of a metallic member, covering the surface of the insulating brush base; the motor housing having a plurality of crimping pieces formed by notching the edge of the motor housing opening; the cover plate being fitted to the motor housing by engaging the cover plate with the motor housing opening, and bending and crimping the crimping pieces, characterized in that the cover plate has along the outer periphery thereof a plurality of recesses, which are concave toward the motor shaft, and the recesses are crimped by means of the crimping pieces so as to fixedly fit the cover plate to the motor housing.

Abstract: A miniature motor having brushgear comprising brush arms with sliding parts on the tips thereof, terminals and brush bases; the brush bases being supported by a motor case cover plate, when the terminals are inserted in brush holes provided on the motor case cover plate; the sliding parts being brought into sliding contact with a commutator by the resiliency thereof, and characterized in that a flexible photo-setting resin having similar resiliency to the resiliency of vibration-damping rubber is applied to the brush arms to prevent the brushes from unwantedly vibrating during rotation of the commutator.

Abstract: A commutator for a miniature motor having a permanent magnet field; comprising a commutator core having a commutator core flat portion, a cylindrical portion provided upright at the center of the flat portion, insert pieces provided in the opposite direction to the cylindrical portion; commutator segments having arc-shaped segment pieces disposed in contact with the outer periphery of the cylindrical portion, and commutator legs disposed along the commutator core flat portion; and a commutator washer engaged with the outer periphery of the arc-shaped segment pieces to fixedly fit the commutator segments to the commutator core; in which winding hooks (in the form of projections or lanced and raised pieces, for example) for hooking rotor windings are provided at predetermined locations of the commutator core flat portions on the sides of the commutator legs disposed in the abovementioned manner.

Abstract: A rotor for miniature motors having an annular spark-quenching element for suppressing electrical sparks generated between commutator segments and brushes, in which the commutator segment is composed of a commutating portion coming into sliding contact with the brushes, and a terminal portion connected to a lead wire of a rotor winding; the terminal portion having an element-retaining portion on which the annular spark-quenching element is mounted; and the annular spark-quenching element being electrically connected to the element-retaining portion, as mounted thereon.

Abstract: A speed control device for d-c motors includes an IC control circuit having such a construction that a reference voltage is generated across two of its terminals C and D. Additionally, a current proportional to the armature current of the d-c motor is kept flowing in the terminal D at all times. A transistor is connected across the terminals C and D of the control circuit so that motor revolution can be changed linearly by means of a variable resistor connected in parallel across the base and collector of the transistor. With this arrangement, the revolution of d-c motors can be accurately controlled.

Abstract: A miniature motor having installed motor components in a housing made of a metallic material and formed into a bottomed, hollow cylindrical shape with an opening at one end thereof; a cover made of a metallic material and formed into a plate shape being fixedly fitted to the opening, in which a plurality of minute ridges are provided on the outside circumferential surface of the cover, and the outside dimensions of the cover are made equal to, or slightly larger than, the inside dimensions of the housing opening so as to ensure a firm press-fit between the cover and the housing opening, thereby maintaining electrical contact between both.

Abstract: A miniature motor having a cup-shaped cylindrical motor case fitted with a plurality of motor mounting holes and a bearing on the closed end face thereof, and a rotor rotatably supported at one end of the shaft thereof in the motor case by the bearing provided on the closed end face of the motor case, a motor mounting portion is provided around motor mounting holes in a raised fashion from the closed end of the motor case so that the surface of the motor mounting portion intersects with the shaft at substantially 90 degrees. Also, a miniature motor in which the surface of the motor mounting portion is ground and polished is disclosed.

Abstract: A motor comprising a small case having at the center thereof a cylindrical bearing housing for housing a bearing, and at the edges thereof holes through which brush holders receiving and supporting motor terminals connected to brushes extend. A large case forming a motor housing, a earth plate comprising a base having at the central part thereof a contacting and mounting hole into which the bearing housing is inserted and press-fitted, a neck extending from the base flush therewith, an arm extending from the tip of the neck at right angles to the plane of the neck and being inserted into a motor terminal hole on one of the brush holders and a contacting curved portion for making electrical contact with the motor terminal. The earth plate is installed onto the small case by press-fitting the base from the outside to the bearing housing, and press-fitting the arm into the motor terminal hole so as to make electrical contact with the motor terminal.

Abstract: A motor having a housing comprising a case and a case cover, and bearings for supporting a motor rotating shaft fitted to the case and the case cover, respectively. The bearings are secured to the case and include a large diameter portion at one axial end having a diameter larger than the diameter of a bearing mounting hole in the case. The bearings also include a small diameter portion, provided at the other end thereof, which is extended continuously from the large diameter portion via a shoulder having such a diameter as to be fitted into the bearing mounting hole in the case. A recess is provided on the end face of the small diameter portion so as to permit a substantial increase the distance l between the bearings.

Abstract: A shallow cup-shaped miniature motor having a motor case of a substantially shallow cup shape, fitted with a permanent magnet field; a motor case cover engaged with the open end face of the motor case; a rotor having a motor rotating shaft rotatably supported by a first bearing provided on the closed end face of the motor case and a second bearing provided on the motor case cover; brushes supported by the motor case cover for making sliding contact with commutator segments provided on the motor rotating shaft, in which an insulating core having wing portions substantially covering a laminated core comprising the rotor is provided on the outermost end face of the laminated core; the insulating core having at the center thereof a through hole through which the motor rotating shaft is passed, and a hollow cylindrical portion, provided around the through hole, having a plurality of notches for engaging with a plurality of the rising portions of the commutator segments; a commutator surface comprising the commutat

Abstract: A vibration-damping device for miniature motor brushgear comprising brush arms having sliding parts at the tips of a plurality of fork-like prongs, terminals and brush bases; the brush bases are supported by a motor case cover and the brush arm sliding parts make sliding contact with a motor commutator by the resiliency of the brush arm in which a soft photo-setting resin is applied on areas at the tips of the brush arms, other than the sliding parts, in such a manner that the fork-like prongs and/or gaps between the prongs are covered by the soft photo-setting resin. The fork-like prongs are individually and separately movable by controlling the flexibility of the soft photo-setting resin, by setting the coating weight or hardness after cure of the soft photo-setting resin to a predetermined value, or by applying soft photo-setting resin having different hardness values in multiple layers.

Abstract: Miniature rotary machinery with brushgear comprising two arm guides, to which power supply voltage is fed, provided on the inside of a motor case cover; and brush arms having brushes at the tip thereof and brush arm eyes, for rotatably engaging with the arm guides, at the other end thereof, and spring receptacles, made of an insulating material, at the center thereof; both ends of an arc-shaped leaf spring being engaged with the spring receptacles to impart pushing force to the brushes by the resiliency thereof; the brush arm eyes being disposed so as to make contact with the arm guides at a predetermined angle; each of the brush arm eyes having a formed portion whose crosssection includes two mutually intersecting tangent lines making contact with the circular crosssection of the arm guide so that two-point contact is established between the formed portion and the arm guide, when viewed in the crosssectional direction; and if necessary projections or ridges provided on the outer circumferential surface of th