Abstract: A molded rotor assembly (20) including at least one molded fan (28), a method for making the same, and a vehicle alternator (160) using the molded rotor assembly (20) are disclosed. The rotor assembly (20) includes first and second pole pieces (24,26) aligned along a longitudinal axis (40) defining a region (122) between the pole pieces (24,26). Each pole piece (24,26) has an outboard axial face (69,71). At least one molded fan (28) is integrally molded to one of the axial outboard faces (69) of a pole piece (24). Preferably, a molded insert (22) is molded in the region (122) between the pole pieces (24,26) and is integral with the molded fan (28) to secure the molded fan (28) to the pole piece (24). Alternatively, anchoring recesses (241,245) are formed in an outboard face of a pole piece (224) with a molded fan (228) having anchoring portions (249,251) secured within the recesses (241,245) to retain the fan (228) to the outboard axial face.

Abstract: The electrically motorized wheel assembly comprises a hollow shaft having a first opening at one end thereof and a second opening, the first opening receiving conductors from outside of the assembly; a stator coaxial with and fixedly attached to the shaft, the stator being provided with a hollow portion and coils; a rotor coaxial with the stator and mounted for rotation about the stator; and converting system for converting an input electrical current to a variable AC electrical current, the converting system including power electronics fixedly mounted within the hollow portion, input terminals for receiving the input electrical current and output terminals for delivering the variable AC electrical current; whereby, to provide the variable AC current to the coils of the stator.

Abstract: A vibrator motor has an armature rotor whose center of mass is off the axis of the shaft thereof. The rotor includes at least three poles each having an winding arm and an arcuate pole blade. All of the blades have an equal length and are disposed angularly evenly about the axis of the shaft so that all of the blade-to-blade spacings are equal. At least one winding arm is angularly out of alignment with the dimensional center of the arcuate blade of the corresponding pole, or, the size and the mass of at least one arm is different from those of any other arms, or, the mass of at least one of armature windings is different from the mass of any other armature winding, or, a weight is fixedly attached to the rotor in an eccentric manner either between two armature poles or on the shaft.

Abstract: A spindle motor includes a housing, a shaft member fixed in the housing, a rotor rotatably supported on the shaft member, a rotor magnet mounted on the rotor, and a stator placed facing with the rotor magnet. The housing and the shaft member are made of materials different in hardness and a sleeve having substantially the same level of hardness as the shaft member is placed between the housing and the shaft member. A bushing is provided between bearing members and the rotor which is rotatably supported by the bearing members. The bushing and a yoke which is mounted on the rotor are secured together in the axial middle part of the bushing. In addition, through holes which enable communications between the interior and exterior area of the motor are provided in the bushing.

Abstract: A brushless electric motor with Hall-effect sensors is configured to provide its stator structure with a portion which projects axially away from a main armature. The projecting portion is radially congruent with a second, smaller armature coaxial with the main armature, with a portion of a sleeve in which the sensors are disposed in circumferentially spaced configuration, and with a laminated annular shield iron. The annular shield iron is radially interposed between the projecting portion of the stator structure and the sensors. In this configuration, the shield iron serves to close the magnetic field originating from the second armature and interacting with the sensors while simultaneously shielding the sensors from field effects attributable to current flow in the axially projecting portion of the stator structure.

Abstract: An elongated electric motor having an annular stator with laminations and a segmented rotor on a shaft bearing assemblies provided between the rotor segments support the shaft and rotor. The bearing assemblies include a sleeve for supporting the shaft and a support portion adjacent the stator with a plurality of wheels to disposed thereon. The wheels inhibit rotation of the bearing while at the same time permitting easy longitudinal movement of the bearing relating to the stator. The wheels are provided with a spring characteristic by mounting on an axle which is supported in elastomeric bushings or, alternatively, the axle is supported in a cantilever fashion. The wheels may also be formed of a compressible elastomeric material.

Abstract: A modular rotating rectifier assembly for use with a brushless self-excited, liquid cooled, dynamo electric device such as a generator. The rotating rectifier assembly is positioned in a rotating hollow shaft of the generator and is coupled with a coolant circulating system for transferring heat from the rectifier assembly to the coolant flowing therethrough. The rotating rectifier assembly is positioned inside the shaft in close proximity to a central axis, longitudinally extending through the shaft, thereby minimizing the centrifugal forces induced on the diode components of the rotating rectifier assembly.

Abstract: An electric motor used for example in a magnetic disk drive, includes a rotor having a hub on which the magnetic disk is mounted, and an annular driving permanent magnet, and rotating together with a rotary shaft, and a stator disposed outside the rotor, having a core and coils wound on the core. A signaling permanent magnet for detecting the rotary angle or the rotational speed of the rotor may be provided on the radially inner side of the driving permanent magnet. Part of the outer periphery of the stator core may be retracted radially inward or cut away to form a concavity or an open part. A magnetic shielding plate may further be provided to cover the coils, with part or the entirety of the magnetic shielding plate being positioned closer to the rotary shaft than the outermost periphery of the rotor to prevent the escape of the rotor in the direction of the rotary shaft.

Abstract: A spindle motor comprising a bracket, a hub which is rotational relative to the bracket, and bearing means disposed between the bracket and the hub, wherein the hub has a hub main body made of aluminum or an aluminum alloy, and a holder formed from a magnetic material, and wherein a rotor magnet is mounted on the inner surface of the holder. A ring-shaped recess is provided on the inner surface of the bracket, and the hub and a part of the rotor magnet extend into the ring-shaped recess. Improvements having been made on a disk clamp mechanism for mounting a recording disk on the hub of the spindle motor.

Abstract: A hand-guidable electric machine tool has a casing having an air guide duct, a tool part, a motor for driving the tool part, and a radial blower for cooling the motor, the radial blower having a fan wheel for forming a static pressure differential. The air guide duct has an inlet opening and an outlet opening and continuously widening in cross-section in a direction of the outlet opening. The cross-section measured in radial direction of the inlet opening of the air guide duct is smaller than the cross-section of the outlet opening.

Abstract: A vibration driven motor including a vibration member for generating a vibration therein, a rotor arranged in frictional contact with the vibration member and driven by the vibration, a rotary output member, and a connection member connecting the rotor to the output member. The connection member includes a bent portion that is deformed in an axial direction on the rotary output member. In another aspect a connection member having a bent portion may be provided for engaging the vibration member at a predetermined portion. In each case, the bent portion(s) of the connection member absorbs any change in the dimensions thereof, e.g., due to a change in the temperature or other environmental factors.

Abstract: A cover device for use with a fan-cooled motor which is generally exposed to harsh conditions during the operating cycle. A fan enclosure having an inlet port is provided which further includes a splash cover extending longitudinally of the motor body. The structure substantially obviates debris accretion in the heat sink of the motor and at the fan to promote cool running for long periods of time.

Abstract: A width-extensional mode quartz crystal resonator formed by etching from a quartz crystal plate which is cut along a plane defined in the O-xyz coordinate system of the quartz crystal lattice by rotating the original Z plane around the x axis by a rotation angle in the range of 23.degree.-28.degree.. The quartz crystal resonator has a thickness-to-width ratio R.sub.zx in the range of 0.45-0.65. A pair of exciting electrodes are disposed on the resonator along opposed side faces perpendicular to the widthwise direction. The width-extensional mode quartz crystal resonator may be etched from a quartz crystal plate to provide a small sized resonator. A width-extensional mode vibrational portion is supported at its lengthwise sides by a pair of first bridge portions extending from a first frame portion. A pair of second bridge portions extend from a second frame portion and support the first frame at central portions of its lengthwise sides.

Abstract: A predetermined inductance element L is connected serially or in parallel with a selfelectrostatic capacitance C.sub.d of a vibrator of a vibration driven motor, a serial resonance or a parallel resonance of the above LC circuit is used, and thereby provides an optimum driving circuit for the vibration driven motor.

Abstract: A motor has a shell formed to include an edge defining an opening that is either U-shaped or rectangular. A reversible apparatus has segments for mounting an overload protector having first and second body portions within the opening in the motor shell. The apparatus has a first profile for mounting the overload protector within a U-shaped opening in a motor shell so as to restrict movement of the mounting apparatus and overload protector assembly relative to the motor shell, and a second profile for mounting the overload protector within a rectangular opening in a motor shell so as to restrict movement of the mounting apparatus and overload protector assembly relative to the motor shell.

Abstract: To provide a disk unit with a reduced thickness, a motor substrate for mounting an inner rotor, outer rotor or belt drive type motor for rotating a magnetic recording medium, includes an extension portion which extends beyond the magnetic recording medium, to which electronic parts and a connector are mounted, so that they do not interfere with the magnetic recording medium.

Abstract: An air guide and motor housing assembly for use in domestic and commercial vacuum cleaners is described wherein the assembly comprises an air guide having a center detail for engaging the motor housing to facilitate assembly of the components, and reduce creep, turbulence and vibration-induced noise. An air guide for use with a centrifugal fan is described wherein the air guide is mounted on a motor bracket using the same rivets that fasten a bearing assembly to the motor bracket. Alternative embodiments of the device are also described in which a step in an inner fan housing cooperates with a step projecting from the air guide to securely fasten the air guide to the motor assembly, and a center detail on the air guide engages the motor housing to secure the air guide thereto, thereby providing the same advantages.

Abstract: In radio communication equipment, a ladder-type piezo-electric filter is provided which operates in a high-frequency region of approximately 1.7 MHz-2 MHz. The filter is smaller than conventional ladder-type electric filters, less costly, and more easily handled and produced. In accordance with the present invention, rectangular piezo-resonators that longitudinally generate harmonic oscillation are used in the series and parallel branches of a ladder-type circuit. In each resonator, piezo-electric regions are formed by dividing surface electrodes with isolating slits. The slits are formed at the positions corresponding to the node points of the harmonic oscillation waveforms. For the piezo-resonators placed in the series branches of the ladder-type circuit, the piezo-electric regions are polarized in the same transverse direction. In each piezo-resonator used in a parallel branch, the piezo-electric regions are polarized in alternately opposite transverse directions.

Abstract: A laminated, metal-polymer-metal PTC resistor (8) is held in the end cap (2) of an electric motor. Substantially parallel opposed surfaces (9 and 10) of the PTC resistor (8) are engaged by electrically conductive members (11 and 12) which are respectively connected to one of the brushes (5) and one of the motor terminals (6) so that the supply of electricity is interrupted when the PTC resistor (8) is heated above a predetermined temperature as a result of excessive current flow. The PTC resistor (8) is supported against movement perpendicular to the substantially parallel opposed surfaces (9 and 10), at least in one direction, and therefore independently of at least one of the contact members (11 and 12) so that, at most, only one of the contact members (11 and 12) is needed for supporting the PTC resistor (8). Both contact members (11 and 12) can therefore make point contact with the PTC resistor (8) and this improves operation by inhibiting the conduction of heat to or from the PTC resistor (8).

Abstract: In a liquid-cooled electric generator, in particular a three-phase generator for motor vehicles and the like, having a rotor, a stator and a housing which accommodates the latter two and forms the bearing for the rotor shaft, as well as a device for liquid cooling (oil or water cooling) having a cooling jacket for a cooling liquid, the cooling jacket, on the one hand, is bounded by the closed external surface of the generator housing and, on the other hand, by a part, which has an accommodating cavity, of an engine block or gear block or similar unit to which the generator is attached and in which it is inserted.