Abstract: Grease for a rolling bearing of an information recording and reproducing apparatus 1 contains a base oil and a thickener, wherein the film thickness of an elasto-hydrodynamic lubrication film is 20 nm or greater. Grease for a rolling bearing of an information recording and reproducing apparatus 1 contains a base oil, and a thickener, wherein a width of the thickener in the grease is 20 nm or greater. A rolling bearing includes the grease for a rolling bearing. A rolling bearing device 6 includes a shaft and the rolling bearing. An information recording and reproducing apparatus 1 includes the rolling bearing device 6.

Abstract: Provided is grease for a rolling bearing of an information recording and reproducing apparatus 1, containing a base oil, a thickener, and at least one kind of an antioxidant selected from an amine-based antioxidant (A) expressed by the General Formula (1), and a phenol-based antioxidant (B) expressed by the General Formula (2).

Abstract: A bearing device includes inner ring rolling surfaces formed so that the external radius of inner end portions of a first inner ring and a second inner ring is smaller than a first separation distance and formed so as to have an external radius that becomes larger from an inner side toward the other side, and outer ring rolling surfaces formed so that the internal radius of outer end portions of a first outer ring and a second outer ring is larger than a second separation distance and is formed so as to have an internal radius that becomes smaller from the outer side toward the inner side.

Abstract: A first inner ring and a second inner ring respectively include inner ring rolling surfaces formed so that the external radius of inner end portions is smaller than a first separation distance and formed so as to have an external radius that become larger than the first separation distance, and a first outer ring and a second outer ring respectively include outer ring rolling surfaces formed so that the internal radius of outer end portions is larger than a second separation distance and formed so as to have an internal radius that becomes smaller than the second separation distance, and the first outer ring and the second outer ring are formed integrally with each other to form an outer ring.

Abstract: A first inner ring and a second inner ring respectively include inner ring rolling surfaces formed so that the external radius of inner end portions is smaller than a first separation distance and formed so as to have an external radius that become larger than the first separation distance, and a first outer ring and a second outer ring respectively include outer ring rolling surfaces formed so that the internal radius of outer end portions is larger than a second separation distance and formed so as to have an internal radius that becomes smaller than the second separation distance, and the first outer ring and the second outer ring are formed integrally with each other to form an outer ring.

Abstract: A bearing device includes inner ring rolling surfaces formed so that the external radius of inner end portions of a first inner ring and a second inner ring is smaller than a first separation distance and formed so as to have an external radius that becomes larger from an inner side toward the other side, and outer ring rolling surfaces formed so that the internal radius of outer end portions of a first outer ring and a second outer ring is larger than a second separation distance and is formed so as to have an internal radius that becomes smaller from the outer side toward the inner side.

Abstract: An ultrasonic motor exhibits stable performances by suppressing irregularities of magnitudes of two standing waves excited by a piezoelectric element. A plurality of divided electrodes are mounted on one surface of the piezoelectric element and are equidistantly arranged in the circumferential and radial directions and have equal polarized areas. Alternate ones of the divided electrodes are short-circuited in the radial direction by inner electrodes arranged on the inner peripheral side of the divided electrodes, and the other alternate ones of the divided electrodes are short-circuited in the radial direction by outer electrodes arranged on the outer peripheral side of the divided electrodes.

Abstract: An ultrasonic motor which exhibits stable performances by suppressing irregularities of magnitudes of two standing waves excited by a piezoelectric element is provided.

Abstract: To provide a piezoelectric actuator that is small in size, large in displacement, high in rigidity, excellent in controllability, and excellent in stability, the present invention provides a piezoelectric actuator, including: a first piezoelectric member that is bent and displaced in a thickness direction; and a second piezoelectric member that is bent and displaced in a direction opposite to the first piezoelectric member. In the piezoelectric actuator, the first piezoelectric member and the second piezoelectric member are stacked on each other in the thickness direction of the first piezoelectric member and the second piezoelectric member, and the center portion in the longitudinal direction of the first piezoelectric member and the center portion in the longitudinal direction of the second piezoelectric member, or both ends of the first piezoelectric member and both ends of the second piezoelectric member are fixed to each other.

Abstract: The present invention provides an ultrasonic motor including a wire having a coiled stator at one end thereof, a vibration generating device disposed at another end of the wire, a moving member that is in contact with the stator, a guide member that guides the rotation of the moving member, and an elastic member that covers the periphery of the wire. Accordingly, the driving efficiency of the ultrasonic motor that has a simple structure and that can be easily downsized can be enhanced and the performance stability thereof can be realized.

Abstract: An electric motor has a rotor having an end portion and a recessed portion formed at the end portion. A rotational shaft is mounted to the rotor. A stator covers an outer peripheral portion of the rotor and forms a magnetic field that generates a torque around the rotational shaft to thereby rotate the rotational shaft and the rotor. A bearing rotatably supports the rotational shaft and is entirely spaced-apart from the end portion of the rotor in an axial direction of the rotational shaft. A slider is slidably mounted around the rotational shaft and supports rotation of the rotational shaft about a rotational axis thereof. The slider is interposed between the bearing and the rotor so that a portion of the slider is entirely contained in the recessed portion of the rotor and the remaining portion of the slider is disposed in the space between the bearing and the rotor and in contact with the bearing.

Abstract: Disclosed is an ultrasonic motor whose output is improved by enhancing the exciting force of a vibration caused on a vibrating body having a rectangular portion. The ultrasonic motor includes the vibrating body having a piezoelectric element, and a moving body which contacts the vibrating body. The phases of two difference vibrations caused on the vibrating body are changed to make the moving direction of the moving body or the vibrating body itself variable by selecting whether to apply a drive signal to first electrodes provided at one side of the piezoelectric element or to apply a drive signal to second electrodes provided at a portion whose polarization direction differs from that of the first electrodes.

Abstract: Disclosed is an ultrasonic motor whose output is improved by enhancing the exciting force of a vibration caused on a vibrating body having a rectangular portion. The ultrasonic motor includes the vibrating body having a piezoelectric element, and a moving body which contacts the vibrating body. The phases of two difference vibrations caused on the vibrating body are changed to make the moving direction of the moving body or the vibrating body itself variable by selecting whether to apply a drive signal to first electrodes provided at one side of the piezoelectric element or to apply a drive signal to second electrodes provided at a portion whose polarization direction differs from that of the first electrodes.

Abstract: To provide a piezoelectric actuator that is small in size, large in displacement, high in rigidity, excellent in controllability, and excellent in stability, the present invention provides a piezoelectric actuator, including: a first piezoelectric member that is bent and displaced in a thickness direction; and a second piezoelectric member that is bent and displaced in a direction opposite to the first piezoelectric member. In the piezoelectric actuator, the first piezoelectric member and the second piezoelectric member are stacked on each other in the thickness direction of the first piezoelectric member and the second piezoelectric member, and the center portion in the longitudinal direction of the first piezoelectric member and the center portion in the longitudinal direction of the second piezoelectric member, or both ends of the first piezoelectric member and both ends of the second piezoelectric member are fixed to each other.

Abstract: The present invention provides an ultrasonic motor including a wire having a coiled stator at one end thereof, a vibration generating device disposed at another end of the wire, a moving member that is in contact with the stator, a guide member that guides the rotation of the moving member, and an elastic member that covers the periphery of the wire. Accordingly, the driving efficiency of the ultrasonic motor that has a simple structure and that can be easily downsized can be enhanced and the performance stability thereof can be realized.

Abstract: To provide an electric motor efficiently operating a torque to a rotor by a stator while preventing an increase in a friction load by a slider and capable of achieving small-sized formation of a total of an apparatus in an axis line direction, an electric motor 1 includes a rotor 3 substantially in a cylindrical shape, a rotating shaft 4 provided at a center of rotation of the rotor 3, a stator 5 for covering an outer peripheral portion 3a of the rotor 3 and having yokes 23, 24 capable of operating a torque around the rotating shaft 4 of the rotor 3 by forming a magnetic field, bearings 13, 14 fixed by the stator 5 by support members 11, 12 for supporting the rotating shaft 4 rotatably, and sliders 8 substantially in a plate-like shape interposed between the bearings 13, 14 and end portions 3c of the rotor 3, and the end portion 3c of the rotor 3 is formed with a first recessed portion 6 for containing at least a portion of the slider 8 in an axis line L direction of the rotating shaft 4 slidably around the r

Abstract: An ultrasonic motor constructed so as to have improved driving force, reduced vibrational loss and smaller dimensions as compared with the conventional art. A piezoelectric vibrator generates a vibrational driving force in response to a received drive signal. A drive signal generator generates the drive signal. The drive signal is transmitted along leads to support members. The support members support, and are in electrical connection with, the piezoelectric vibrator on the substrate. Thus, the support member is effective for both supporting the piezoelectric member and for transmitting the drive signal from the drive signal generator to the piezoelectric vibrator. A moving member is in communication with the piezoelectric vibrator and moves in response to the vibrational driving force. The support member may be comprised of an elastic material so that it is effective for urging the piezoelectric vibrator against the moving member.

Abstract: An ultrasonic motor comprises a piezoelectric vibrating member having a detecting polarized portion for detecting a drive signal having a drive frequency of the detecting polarized portion and a driving polarized portion for receiving the drive signal to oscillate the piezoelectric vibrating member in self-excited oscillation to produce a drive force. The detecting polarized portion is disposed at a portion of the piezoelectric vibrating member for undergoing maximum deformation in at least one vibration mode of oscillation of the piezoelectric vibrating member. An amplifying circuit amplifies the drive signal detected by the detecting polarized portion and inputs the amplified signal to the driving polarized portion to oscillate the piezoelectric vibrating member.

Abstract: To provide a control system provided with a positioning mechanism including plural ultrasonic motors in the device, which can keep good operational stability as compared with a conventional system with a servo mechanism, is of an energy saving type suppressing power consumption and is compact in structure including the motor and a control circuit therefor. A control circuit in a control system of the present invention uses a common drive control circuit for a plurality of ultrasonic motors among the positioning mechanisms in which when the drive control circuit inputs a signal that specifies any ultrasonic motor and a desired-position designation signal, the drive control circuit conducts control operation that transmits an on signal to a driver of the subject motor to start the driving, and stops the driving when the motor reaches a desired position while receiving a position detection signal.

Abstract: A piezoelectric motor has a vibrating body for undergoing vibrational movement in accordance with a vibration wave, a contact member disposed in contact with and driven by the vibrating body during vibration thereof, and a support member for supporting the vibrating body in the vicinity of a vibration node of the vibration wave. A pressurization member applies pressure to the support member along a pressurization axis to maintain the vibrating body in pressure contact with the contact member so that during vibration of the vibrating body, the support member regulates movement of the vibrating body in a direction of rotation about the pressurization axis.