Abstract: A first member, a second member, a bearing that rotatably supports the second member about a rotation axis relative to the first member, a driven member placed on the first member, and a plurality of piezoelectric actuators that transmit driving forces for rotating the second member about the rotation axis relative to the first member to the driven member are provided, and the piezoelectric actuators are supported by the second member while being pressed against the first member or the member fixed thereto, and, as seen from a direction along the rotation axis, a center of pressing forces from the plurality of piezoelectric actuators to the driven member is located inside of an outer circumferential part of the bearing.

Abstract: A driving device includes a stepping motor having a rotor, a coil for rotating the rotor, and a processor that drives the stepping motor. The processor generates a driving pulse for rotating the rotor of the stepping motor to a prescribed position, and outputs the driving pulse to the coil; and generates a rotation assistance pulse for rotating the rotor of the stepping motor at a prescribed speed, and outputs the rotation assistance pulse to the coil, after outputting the driving pulse but before EMF is produced by the rotation of the rotor of the stepping motor caused by the driving pulse.

Abstract: Exchangeable stator components are selected and exchangeable rotor components are selected to transform a motor from one motor class to another motor class. A motor class includes a switched reluctance (SR) motor class, a parallel path magnetic technology (PPMT) motor class, or an interior permanent magnet (IPM) motor class.

Abstract: The invention refers to a Rotary Solenoid comprising a stator and rotor that can rotate around a rotational axis. The rotor has a rotor shaft on which a rotor disc is arranged. The rotor disc is, seen in the direction of the circumference, polarized alternating magnetically. The stator carries at least one coil. On the coil windings of electrically conducting wire are provided. For guiding the magnetic flow of the magnetic field generated by the coil a pole face consisting of several partial pole faces is provided.

Abstract: A method is provided for compensating the flux drift caused by measurement and/or calculation errors when controlling a rotating electrical machine. The flux drift of the estimated flux vector may be compensated for by comparing the length of the flux vector with a reference flux magnitude which already has been determined for controlling the inverter. Depending on the comparison, the length of the estimated flux vector may be lengthened or shortened.

Abstract: The present invention relates to a stepping motor with a magnet pole pattern having a predetermined pattern around the circumference of the stepping motor. In one embodiment, the pattern relates to a code having a unique single maximum autocorrelation peak over the period of the code. Example codes include Barker codes, PN codes, Kasami codes, Golomb ruler codes, and other codes. In one embodiment, the rotor and stator have a matching pole pattern. In one embodiment, the drive is arranged to align the poles in an inline configuration, alternatively, the drive may be arranged to align the poles in a diagonal configuration. In a further embodiment, one or more sets of poles are provided on the stator, each set being offset rotationally by a partial pole spacing. In one embodiment, the rotor is initially synchronized with the stator by capturing the rotor using a single unambiguous lock-in position based on the code autocorrelation.

Abstract: A high-efficiency motor is disclosed. The motor includes two sets of permanent magnets and further includes electromagnets incorporated to be energized by a control system to provide a variable-speed motor that produces high torque.

Abstract: A drive apparatus which is small in size, short in axial length, low in cost, and high in output. A stepping motor as the driving apparatus includes a first coil, a second coil, a magnet, and a rotor comprised of a core and a rotary shaft. First through fourth outer magnetic pole portions are opposed to the outer peripheral surface of the magnet with a predetermined gap between them. The first and the second coils are disposed adjacent to the magnet in an axial direction of the rotary shaft and disposed at respective ends of the rotary shaft. The first and second outer magnetic pole portions are inserted inside the first and second coils, respectively. As viewed in the circumferential direction of the magnet, the third and fourth outer magnetic pole portions are disposed close to the first and second outer magnetic pole portions, respectively.

Abstract: A hybrid step motor comprises a stator, a rotor assembly, a magnet and a mandrel. The rotor assembly and the magnet are mounted on the mandrel and are disposed in the stator. The proportion of a stator outer diameter to a stator inner diameter is 1:0.475 to 1:0.6. The proportion of the stator outer diameter to a rotor outer diameter is 1:0.5125 to 1:0.5875. The proportion of a first rotor thickness to a magnet thickness to a second rotor thickness is 0.236:0.09:0.236 optimally. The proportion of the rotor outer diameter to a magnet outer diameter is 0.54:0.45. By such arrangements, the optimal proportion is formed and the output efficiency is improved.

Abstract: A motor includes a shaft including upper and lower shaft members spaced axially away from each other. A shaft connecting member made of electrically insulating material is arranged axially between the upper and lower shaft members. The shaft connecting member is provided with fitting portions to which the upper and lower shaft members are to be fitted. While the upper and lower shaft members are secured to the shaft connecting member, the rotor magnet is integrally formed with the upper and lower shaft members and the shaft connecting member. With this configuration, an axial electric current is prevented from flowing through the shaft by the shaft connecting member.

Abstract: The multiphase step motor is capable of reducing vibrations of a rotor and torque ripples in spite of switching current flowing through stator coils. Stator units are divided into 2n (n is an integer one or more) per one phase and coaxially layered, and the stator units of the same phase are plane-symmetrically layered with respect to a plane perpendicular to an axial center of a stator.

Abstract: A stepping motor is provided with a rotor having with a rotor shaft A permanent magnet is attached to an outer peripheral side of the rotor shaft and a stator having pole teeth faces the permanent magnet in a radial direction. The stepping motor is characterized in that the rotor shaft is formed of aluminum or aluminum alloy.