Abstract: In order to make it possible to ensure the axis alignment performance while reducing the processing cost, and to make a coupling structure compact to perform the coupling work and the detaching work of pipe members without difficulty even in a narrow work space, the coupling structure according to the invention includes a pipe coupling that couples a pair of pipe members each including a flange at an end portion in a state where the flanges of the pipe members face each other, an annular gasket interposed between the flanges of the pair of pipe members, and recesses formed individually in facing surfaces of the flanges facing each other, in which the annular gasket fitted into the respective recesses makes pipe axes of the pipe members and the annular gasket coincide with each other.

Abstract: A rotary electric machine of the embodiment includes a stator including a cylindrical stator core, and a coil mounted on the stator core, and a rotor disposed radially inward of the stator, wherein the rotor includes a rotor core having a rotor internal flow path through which a refrigerant is able to flow by axial center cooling, and an end surface plate disposed at an end of the rotor core in an axial direction, and the end surface plate includes a refrigerant flow hole configured to communicate with the rotor internal flow path, and a surface treatment portion disposed at least between the refrigerant flow hole and an outer peripheral edge of the end surface plate, and a surface tension of the surface treatment portion is smaller than that of the end surface plate.

Abstract: An output circuit of a PWM inverter for PWM controlling a coil voltage of a motor includes an N channel power element, a P channel power element, a current control circuit having a current output terminal, and a second current control circuit having a current input terminal. A current flowing out from the current output terminal of the first current control circuit and a current flowing in from the current input terminal of the second current control circuit are subjected to particular control to thereby control the N channel power element and the P channel power element. The output circuit of the PWM inverter is configured inexpensively to control a voltage of a motor winding terminal with very small error and with low power consumption.

Abstract: An inexpensive output circuit of a PWM inverter for PWM controlling a coil voltage of a motor with small control error of voltage at a motor winding terminal and low power consumption includes an N channel power MOS-FET, a P channel power MOS-FET, a current control circuit 1 having a current output terminal, and a current control circuit 2 having a current input terminal. A current flowing out from the current output terminal of the current control circuit 1 and a current flowing in from the current input terminal of the current control circuit 2 are subjected to particular control to thereby control the N channel power MOS-FET and the P channel power MOS-FET.

Abstract: In a driving apparatus for ultrasonic motor, a variable oscillator (44) varies oscillating frequency responding to current level of detected current which flows to a piezoelectric member (1, 2) and is in proportion to mechanical vibration of the piezoelectric member (1, 2) when mechanical resonance frequency varies by change of environmental condition.

Abstract: An enclosure for a disk drive which may serve as an external store of a computer is constituted by a two-sided printed circuit board, a frame, and a top board, the printed circuit board being loaded with a disk driving section. The printed circuit board, frame, and top board have substantially the same coefficient of linear thermal expansion. The printed circuit board is prevented from being deformed by heat, so that the accuracy of the disk driving section is maintained to insure stable recording and playback.

Abstract: A disk drive unit such as a magnetic disk drive unit has a read/write head for recording signals on and reproducing signals from an information storage disk, a motor energizable by a power supply for driving the read/write head in the radial direction of the information storage disk, an auxiliary head driver responsive to turning-off of the power supply for enabling the motor to drive the read/write head radially toward a non-recording area of the information storage disk, and a head locking mechanism responsive to turning-off of the power supply for locking the read/write head having reached the non-recording area.

Abstract: A feed mechanism for moving a read/write head in a disk drive unit includes a pinion drivable by a motor, a rack held in mesh with the pinion, a support on which the rack is pivotally mounted and which is movable with the rack in a linear direction, and a compression resilient member such as a compression coil spring or a torsion spring having one end fixed to the rack and an opposite end fixed to the support for urging the rack in forced mesh with the pinion and for urging the rack in the linear direction. The feed mechanism also includes a pinion holder fixedly mounted on the rack and extending along the linear direction, the pinion holder having a member disposed in confronting relation to the pinion and spaced therefrom for preventing the rack and the pinion from being thrown out of mesh with each other.

Abstract: A rotating recording medium such as a video disc placed on a turntable is played back by a signal pickup head movable radially over and across the disc. The disc is removably housed in a disc case composed of a jacket for containing the disc and a lid plate closing a slot in the jacket. When the disc case is inserted, it pushes a jacket opener over and across the turntable while the slot is opened by the jacket opener for removal of the disc. When the disc playback apparatus is not in operation or the disc is being played back, the jacket opener is firmly locked by a locking mechanism against movement into the apparatus, so that forced entry of a disc case into the apparatus is prevented. Since the jacket opener is locked at laterally spaced positions by the locking mechanism, the jacket opener is rigidly kept in the locked position against the operator's undue attempts to insert the disc case.

Abstract: An apparatus for reproducing rotary recording media has an inserting opening on its front side. A rotary recording medium is accommodated within a case having a jacket and a lid member for closing an opening of the jacket. The apparatus has a mechanism for enlarging the opening of the jacket as it is inserted into the opening. This mechanism couples with the jacket as it moves over a turntable positioned between the inserting opening and a rear part of the reproducing apparatus. A switch mechanism (comprising a microswitch) detects a movement of the jacket opening enlarging mechanism. The microswitch is positioned opposite the jacket opening enlarging mechanism and near the inserting opening. The microswitch remains operated as long as the jacket opening enlarging mechanism is moved away from the inserting opening. The microswitch returns to normal when the jacket opening enlarging mechanism moves back to its normal position near the inserting opening.

Abstract: A rotary recording medium reproducing apparatus comprises a turntable onto which a rotary recording medium is placed, a motor for rotating the turntable, a reproducing transducer for reproducing a recorded signal from the rotary recording medium placed onto the turntable, and a clamping mechanism for clamping the rotary recording medium on the turntable.