Abstract: A database managing system for effecting management in accessing data stored in a database via an index is so configured so as to prevent duplication of index key values and increase of index key values from degrading the access performance and lowering the storage efficiency of the index. Upon receiving, from an application program, a request to add a data record, a database manager adds this data record to a data portion and effects addition and update of an index record in an index portion. An index manager intervenes in this processing and excepts, from the index portion, an index record containing an index key value which has reached an upper limit value of the number of duplications preset in an exception key managing table. At the time of recreation of the index, the index manager refers to access time contained in index records and excepts index records which have not been accessed during an elapse of a fixed period of time.

Abstract: In a reluctance type synchronous motor, a rotor has magnetic poles which have a low magnetic reluctance in an axial direction of the magnetic poles, and have a high magnetic reluctance toward a circumference of the rotor. The magnetic poles have less components orthogonal to axes thereof, so that armature reaction will be reduced.

Abstract: A motor 3 having a rotational shaft with a counterweight 4 is held in a vibrator holder 2. The rotational shaft of the motor is inserted at a free end in a circular hole in a bearing-plate of the vibrator holder 2. The vibrator holder 2 with the motor therein is accommodates in a vibrator accommodating section 120 formed in a housing 12 of a portable terminal and fixed with screws 5 to the housing 12. The vibrator holder 120 is then covered with an index cover 17 to thereby complete the vibrator attachment, which reduces a vibrator attaching work load. The inner wall of the vibrator accommodating section 120 faces the motor to thereby prevent the motor 3 from slipping from the holder.

Abstract: A permanent magnet motor with enhanced inductance which comprises a motor frame having annular inner walls defining a void therein and a stator mounted on and extending around the periphery of the inner walls of the frame in the void in the motor frame. The stator includes windings positioned thereon for developing current from power supplied to the motor, the innermost portion of the stator defining a radial inner portion of the void. A rotor is mounted in the void radially inwardly of the stator for concentric rotation in the motor frame in closely spaced-apart relation to the stator. The rotor has an iron core for air gap flux interaction with the stator, and the rotor has a magnet zone and a lamination zone extending axially along the length of the rotor. The magnet zone has a permanent magnet positioned on the rotor and projecting therefrom for interaction with the windings on the stator to produce magnetic-field induced torque for rotating the rotor.

Abstract: In a vibrating motor, an eccentric weight is attached to one end of a rotation shaft that projects linearly from a motor housing. The vibrating motor causes the gravity center of the weight to rotate about the rotation shaft so as to produce a vibration. A disk-shaped anti-bending piece is provided on the rotation shaft coaxial with it. This anti-bending piece faces an anti-bending surface provided on some kind of supporting member when the housing is supported by the member, the piece being situated at a predetermined distance from this surface. If the shaft bends, the piece strikes the surface and the linear shape of the shaft is restored due to its own elasticity. Hence, even if the motor suffers an unexpected load, the rotation shaft does not buckle due to the weight of the eccentric weight.

Abstract: An electric motor comprises a rotor rotational position indicator formed internally with a pole field portion of a rotor thereof, and a notch disposed between the pole field portion and the rotor rotational position indicator for suppressing the magnetic influence, the notch being filled with nonmagnetic materials. By virtue of the notch, the pole field and its magnetic influence upon a sensor can be suppressed, whereby appropriate home position and incremental pulses can be generated to enable accurate detection of a rotational position of the rotor.

Abstract: An electric motor used in an electric type power steering apparatus and the like, wherein a magnetic field unit outer casing 14 for encasing a magnetic field unit 7 comprising magnets 5 and an armature 6, is formed integral and concentric with a motor yoke 3, and a power supply unit outer casing 15 for encasing a commutator 22 and brushes 27 of a power supply unit 8, having a protruding portion 15a protruding from an axially concentric outer peripheral face thereof arranged eccentric to the magnetic field unit outer casing 14, is formed integral with the motor yoke 3. As a result, the influence of shock from the outside is suppressed, and accommodating space for the power supply unit ensured, so that long motor life is possible.

Abstract: Method for dynamically enabling and disabling table locking for a table in a database in a relational database management system. A table locking state is associated with the table and can be set to either enabled or disabled to indicate the current state of table locking for the table. To disable table locking, a user must first acquire an exclusive table lock. To re-enable table locking, a user must wait for any user currently accessing the table to perform e.g., a query, to finish accessing the table before table locking is enabled.

Abstract: An induction motor includes a stator defining stator inner and stator outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the stator outer diameter, passing an electric current therethrough to create a magnetic field, a rotor extending along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator in response to the magnetic field, the rotor including a hoop portion disposed adjacent the rotor outer diameter and extending radially inwardly toward the longitudinal axis, the hoop portion being a solid unitary structure being fabricated of an Aermet alloy material.

Abstract: A dynamoelectric machine stator winding element which has a foreshortened end protruding from the stator of the machine when compared to prior art winding elements. The protruding end of the winding element has only a single bend in its protruding length, whereas the prior art elements always have two bends. A special connector for the winding elements straddles the bared end of each winding element. Connection of each member of the pair of connectors is facilitated by means of a common conducting member which is received in an aperture provided in each connector member.

Abstract: A device is proposed for holding an electric motor which has a tubular housing portion enclosing the motor armature and supports which are associated with the motor housing are arranged at the end sides of the housing portion for the arrangement of bearings for the motor shaft. The motor is held in such a way that vibrations are minimized and noise is damped in that at least one resilient damping member is arranged between the inner walls of the holding device and the outer walls of the motor housing facing these inner walls. The damping member is supported at the walls of the holding device and motor housing which face one another.

Abstract: A rotary electromagnetic actuator comprises a rotatable shaft carrying a rotor which is rotatable relative to a stator. A magnetic circuit is set up which comprises the stator and the rotor, the reluctance of the magnetic circuit being dependent on the relative rotational orientation of the rotor and stator and decreasing in a particular direction of rotation such that the reluctance is a minimum at an equilibrium position to which the rotor is therefore biased. The rotor is selectively impelled to advance away from the equilibrium position, subsequently again becoming part of a magnetic circuit, the reluctance of which decreases in the direction of rotation to a minimum at an equilibrium position to which the rotor becomes biased. The actuator provides undirectional rotation for successive actuations at substantially uniform torque and is suitable for use in actuating rotary devices such as rotary valves.

Abstract: A self-adjusting magnetic bearing automatically adjusts the parameters of an axially unstable magnetic bearing such that its force balance is maintained near the point of metastable equilibrium. Complete stabilization can be obtained with the application of weak restoring forces either from a mechanical bearing (running at near-zero load, thus with reduced wear) or from the action of residual eddy currents in a snubber bearing. In one embodiment, a torque is generated by the approach of a slotted pole to a conducting plate. The torque actuates an assembly which varies the position of a magnetic shunt to change the force exerted by the bearing. Another embodiment achieves axial stabilization by sensing vertical displacements in a suspended bearing element, and using this information in an electrical servo system.

Abstract: A cylindrical bearing box 2 is integrally provided at the axial center of an annular disk 1 on which a flange 1a is formed. A shaft 3 is attached to a pair of bearings 2a, 2b engaged with the bearing box 2. A rotary disk 4 attached the shaft 3 on a side opposite to the drive side is molded integrally with a conductor 5a of a rotor 5 arranged outside of the bearing box 2 in the radial direction. A stator 6 arranged outside of the rotor 5 through a magnetic clearance is attached to the stationary side of the rotary electric machine. A synthetic resin member 7, the electric insulating property and heat conductivity of which are high, is molded in the overall periphery of the stator 6 including the winding 6a and the iron core 6b. An end face of the synthetic resin member 7 on the drive side is closely contacted with the annular disk and attached by a screw 1b. Blades 4a are provided on an outer end face of the rotary disk 4 and enclosed by a fan cover 4b.

Abstract: An electric machine, such as a motor or generator, is configured in a machine housing with a cup-shaped rotor attached to a shaft rotatively supported in the housing, an inner stator coaxial with and enclosed by the rotor, and an outer stator coaxial with and enclosing the rotor. The inner and outer portions of the machine are separated by a magnetic isolator that divides and supports inner and outer portions of the rotor. The magnetic isolator, which supports inner and outer sets of permanent magnets in one embodiment and inner and outer squirrel cage rotor assemblies in another embodiment is preferably made of non-magnetic stainless steel but may also be made of titanium, brass, aluminum, bronze or magnesium, or any material that provides magnetic isolation between the inner and outer portions of the machine.

Abstract: A coreless motor has a cylindrical shell of magnetic material, a column-like magnet securely and coaxially positioned in the shell to form a cylindrical clearance therebetween, and a rotor. The rotor includes a cylindrical winding of a coil, arranged coaxially in the clearance, a commutator mechanically supporting one end of the winding and electrically connected with the coil, and a shaft for supporting the commutator. The motor further includes a pair of brushes arranged in contact with the commutator,such that an electric current is supplied via the commutator to the coil. A first bearing is mounted at an end portion of the magnet adjacent the commutator to rotatably support a first portion of the shaft, and a second bearing is mounted adjacent one end of the shell to rotatably support a second portion of said shaft.

Abstract: In an on-vehicle alternator, both the magnetic flux variation frequency and maximum flux density are decreased sufficiently to thereby decrease the internal iron loss and thereby realize an increase in the current generation efficiency. The on-vehicle alternator comprises a rotor wherein magnetic pole cores that are polarized by a rotor coil to alternately different polarities are circumferentially disposed on the outer periphery thereof at prescribed equi-angular intervals. A permanent magnet which is embedded within a resin-made retainer body is provided between the magnetic pole cores and has side faces, as viewed circumferentially, which are polarized respectively to the same polarities as those of adjacent respective magnetic pole cores to thereby vary the magnetic flux quantity directed toward stator coils so as to exhibit a circumferential gentle curve.

Abstract: A magnetic bearing arrangement for a rotor of a D.C. electric motor, which is rotated due to cooperation of a permanent magnet provided on the rotor and stator coils, and including a magnetic bearing, and at least one additional coil arrangement provided in a region of the permanent magnet at a side of a stator of the electric motor, and in which a voltage is induced by the rotatable permanent magnet means, with the at least one of the amplitudes and at least one of the phases of the relative geometrical position of the at least one additional coil arrangement and the permanent magnet being used as a sensor signal for stabilizing the magnetic bearing.

Abstract: A switched reluctance electric motor is disclosed that includes a stator portion having a plurality of stator poles. Adjacent stator poles are wound with energizing windings and which are connected in-series to form a respective one of a plurality of motor phases of the electric motor. A rotor portion of the electric motor is also disclosed, and is supported for rotation relative to the stator, and which also includes a plurality of rotor poles. An electrical conductor having first and second ends is disposed about the adjacent stator poles for each one of the plurality of motor phases. The first and second ends of each electrical conductor are shorted together to thereby minimize induced flux linkages in non-energized motor phases when one of the motor phases is energized.

Abstract: A rectifying unit is disposed axially adjacent to a rear cooling fan. The rectifying unit has a plus-pole heat dissipating fin and a minus-pole heat dissipating fin integrally connected by a terminal plate. The plus-pole heat dissipating fin has an elongation extending axially around the rear cooling fan to have direct cooling air from the fan. The minus-pole heat dissipating fin is fixed to the housing directly or via a heat conductive material to be electrically grounded. Slits are formed on the elongations of the plus-pole heat dissipating fin to have discharging cooling air therethrough. Further, elongations are formed on the both dissipating fins at their inner periphery proximate to an intake window of the housing. Thus, cooling capacity of the rectifying unit is enhanced.