Abstract: It is an object to provide an ultrasonic motor that can stably and finely (that is, minutely) move a driven body. The invention provides an ultrasonic motor comprising an ultrasonic vibrator which includes an electromechanical transducer and which is configured to simultaneously generate two different vibration modes to produce substantially elliptical vibrations at output terminals by supplying two sets of alternating-current voltages with a predetermined phase difference and a predetermined driving frequency to the electromechanical transducer; and a pressing unit for pressing the output terminals of the ultrasonic vibrator against a driven body. The output terminals include first friction-contact members disposed at positions substantially corresponding to antinodes of a flexural vibration and a second friction-contact member disposed substantially at the center in the longitudinal direction of the ultrasonic vibrator.

Abstract: A method for driving an ultrasonic motor includes the step of applying a driving alternating signal to an ultrasonic vibrator to simultaneously generate two different vibration modes in the ultrasonic vibrator to cause a substantially elliptical vibration at friction-contact members of the ultrasonic vibrator, thus relatively moving the ultrasonic vibrator and a driven body in contact with the ultrasonic vibrator. A preliminary vibration domain in which a preliminary vibration smaller than the substantially elliptical vibration is generated at the friction-contact members is provided prior to a main vibration domain in which the driving alternating signal is applied.

Abstract: An ultrasonic motor includes a vibrator formed by stacking a plurality of rectangular piezoelectric plates in a thickness direction, a driving circuit for applying a driving signal to a piezoelectric plate, and a detection circuit for detecting an electromotive force generated when the piezoelectric plate deforms, and this ultrasonic motor is configured in such a manner that there are a first piezoelectric plate and a second piezoelectric plate among the plurality of rectangular piezoelectric plates, the first and the second piezoelectric plate each is a piezoelectric plate in which a longitudinal vibration polarization portion that can excite longitudinal vibrations and a bending vibration polarization portion that can excite bending vibrations are polarized in a thickness direction, and the first piezoelectric plate is connected to the driving circuit and the detection circuit, and the second piezoelectric plate is connected to the driving circuit and is not connected to the detection circuit.

Abstract: A motorized table apparatus comprises: a support unit for supporting a movement table so as to allow it to move in a single axis direction relative to a stationary unit which is fixed to the movement table; a slide member which is equipped on the movement table and which has a length equivalent to, or more than, a moving range of the movement table; an ultrasonic oscillators which is equipped on the stationary unit, which moves the movement table, and which comprises a single piezoelectric body and two drive elements; and a pressure application unit for supporting so that the two drive elements of the ultrasonic oscillator and the slide member are pressed by a constant force, wherein a plurality of the ultrasonic oscillators are equipped.

Abstract: A method for driving an ultrasonic motor includes the step of applying a driving alternating signal to an ultrasonic vibrator to simultaneously generate two different vibration modes in the ultrasonic vibrator to cause a substantially elliptical vibration at friction-contact members of the ultrasonic vibrator, thus relatively moving the ultrasonic vibrator and a driven body in contact with the ultrasonic vibrator. A preliminary vibration domain in which a preliminary vibration smaller than the substantially elliptical vibration is generated at the friction-contact members is provided prior to a main vibration domain in which the driving alternating signal is applied.

Abstract: It is an object to provide an ultrasonic motor that can stably and finely (that is, minutely) move a driven body. The invention provides an ultrasonic motor comprising an ultrasonic vibrator which includes an electromechanical transducer and which is configured to simultaneously generate two different vibration modes to produce substantially elliptical vibrations at output terminals by supplying two sets of alternating-current voltages with a predetermined phase difference and a predetermined driving frequency to the electromechanical transducer; and a pressing unit for pressing the output terminals of the ultrasonic vibrator against a driven body. The output terminals include first friction-contact members disposed at positions substantially corresponding to antinodes of a flexural vibration and a second friction-contact member disposed substantially at the center in the longitudinal direction of the ultrasonic vibrator.

Abstract: An ultrasonic-actuator driving apparatus includes an ultrasonic actuator including a transducer and a driven body that is in contact with the transducer, the transducer to which a frequency signal is applied friction-driving the driven body; an original-signal outputting unit for outputting an original signal; a waveform averaging unit for averaging the original signals during a predetermined period to calculate average-waveform data; a position detecting unit for detecting an absolute position of the driven body with respect to the transducer; a position averaging unit for averaging the absolute positions during a predetermined period to calculate average-position data; a control-signal calculating unit that generates a control signal for controlling the frequency of the original signal based on the average-waveform data and the average-position data and supplies the control signal to the original-signal outputting unit; and a driving unit for generating the frequency signal based on the original signal and

Abstract: A method is provided to drive an ultrasonic-actuator by supplying an alternating signal to an ultrasonic transducer in which piezoelectric plates and internal electrodes are alternately stacked. A frequency at which a phase difference between a voltage and current of the alternating signal is in a predetermined state is detected from a frequency range in which an amplitude ratio between the voltage and the current of the alternating signal is more than or equal to a predetermined value, and the driving frequency is set to the detected frequency.

Abstract: An ultrasonic actuator driving apparatus which drives an ultrasonic transducer formed by alternately laminating a piezoelectric plate and an internal electrode, by applying a frequency signal to the ultrasonic transducer, includes an oscillating unit which generates the frequency signal for driving the ultrasonic transducer, a driving unit which amplifies the frequency signal and applies the signal to the ultrasonic transducer based on an output from the oscillating unit, a vibration information detecting unit which detects vibration information of the ultrasonic transducer, and, a control unit which detects a frequency near a resonant one of the ultrasonic transducer based on the vibration information, sets the detected frequency as a driving frequency of the ultrasonic transducer, and controls the oscillating unit so as to generate the frequency signal based on the driving frequency.

Abstract: An ultrasonic-actuator driving apparatus includes an ultrasonic actuator including a transducer and a driven body that is in contact with the transducer, the transducer to which a frequency signal is applied friction-driving the driven body; an original-signal outputting unit for outputting an original signal; a waveform averaging unit for averaging the original signals during a predetermined period to calculate average-waveform data; a position detecting unit for detecting an absolute position of the driven body with respect to the transducer; a position averaging unit for averaging the absolute positions during a predetermined period to calculate average-position data; a control-signal calculating unit that generates a control signal for controlling the frequency of the original signal based on the average-waveform data and the average-position data and supplies the control signal to the original-signal outputting unit; and a driving unit for generating the frequency signal based on the original signal and

Abstract: A rotor comprises a rotor body and a ring-shaped rare earth metal-iron type magnet arranged therearound, in which a low thermal-expansion material is inserted between the rotor body and the magnet.

Abstract: A magnet is formed as a ring magnet and magnetized by radial application of a magnetic field while the intensity of the magnetic field is changed periodically along the circumference of the ring magnet to give a circumferentially sinusoidal waveform distribution of magnetic flux density to the ring magnet in the magnetized state of the magnet.

Abstract: A method for producing an anisotropic rare earth magnet is improved by extruding using a compacted material formed in a shape having difference in level between the center part to be in contact with the end face of a punch and the outer peripheral part to be faced with a molding cavity formed between the punch and a cylindrical die of a mold.

Abstract: The ability to hot work RE-Fe-B type compositions to form anisotropic magnets containing Nd.sub.2 Fe.sub.14 B.sub.1 -type crystal grains is improved by the addition of suitable, small amounts of one or more of cerium, lanthanum or yttrium. The improvement in hot working is seen in the reduction of cracks in the deformed body and in the ability to reduce the hot working temperature without a significant penalty in magnetic properties.

Abstract: A method of forming a cylindrical compact for a cylindrical magnet is improved by moving a core pin and a die of a mold at the same time of pressing magnet materials with a pressing punch in the same direction as that of the pressing punch at travelling speed Vc and Vd indicated by following equation:Vc=m.multidot.Vp(0.5.ltoreq.m.ltoreq.1.0)Vd=n.multidot.Vp(0.5.ltoreq.n.ltoreq.1.0)where Vc is the travelling speed of the core pin, Vd is the travelling speed of the die and Vp is the pressing speed of the pressing punch. It is possible to form the thin-walled elongated cylindrical compact by utilizing the frictional force caused between the mold and the magnet materials for forming the compact very effectively in order to obtain a thin walled elongated cylindrical magnet.

Abstract: A method for producing an anisotropic rare earth magnet is improved by applying compressing stress on a free surface of an compacted material at the time of extruding the compacted material in order to prevent forming cracks, and improved by using a double action punch provided with a core punch and a sleeve punch so as to mold a compacted material and extrude the compacted material into the anisotropic magnet material in a single heat process continuously.