Abstract: In the diversity receiver, the RF switcher switches the received signals to supply them to the RSSI power detector equipped with diversity function. Subsequently, the RSSI power detector with diversity function feeds the RF switcher with an antenna switching signal. According to the determination of antennas at this instance, an IQ start-up signal for starting up the I/Q subsection is produced to make the I/Q subsection operate assuredly in response to a signal intended to receive, without operating the I/Q subsection in response to an erroneous detection of noise during processing therein, thereby eliminating useless operation.

Abstract: In the diversity receiver, the RF switcher switches the received signals to supply them to the RSSI power detector equipped with diversity function. Subsequently, the RSSI power detector with diversity function feeds the RF switcher with an antenna switching signal. According to the determination of antennas at this instance, an IQ start-up signal for starting up the I/Q subsection is produced to make the I/Q subsection operate assuredly in response to a signal intended to receive, without operating the I/Q subsection in response to an erroneous detection of noise during processing therein, thereby eliminating useless operation.

Abstract: A method for lubricating a part without leaving air bubbles includes the steps of assembling components so that an open end is formed for application of lubricating fluid and a fluid path is provided through which the lubricating fluid is to be circulated, introducing the lubricating fluid into the open end and applying a centrifugal force to the component by moving the component about a circular path so that the centrifugal force causes the lubricating fluid to be urged throughout the fluid path. The method is used in an embodiment to lubricate a dynamic pressure bearing having a gap between relatively moving parts. The gap has an open end into which the lubrication fluid is dripped and a closed end. During movement of the bearing about a circular path, the fluid is urged from the open end to the closed end.

Abstract: A double sleeve type dynamic bearing comprises a fixed shaft having at least one end fixedly mountable to an apparatus in which the bearing is utilized, a rotary sleeve arranged coaxially with the fixed shaft so that a first fine gap is formed therebetween, a fixed sleeve arranged coaxially with the rotary sleeve so that a second fine gap is formed therebetween, and a lubrication oil filled in the fine gaps. The first fine gap and the second fine gap each have an open end exposed to air outside the bearing and an opposite end that is not exposed to the air, the opposite ends being in communication with each other. A holding member holds the fixed shaft and the fixed sleeve and is disposed adjacent to a lower end surface of the rotary sleeve to form a third fine gap between the holding member and the lower end surface of the rotary sleeve. The third fine gap is formed with a thrust dynamic pressure producing groove, and opposite ends of the first and second fine gaps meet each other through the third fine gap.

Abstract: The present invention is a double sleeve type fluid dynamic pressure bearing, comprising a fixed shaft having respective ends to be fixed to a utilized apparatus; a rotary sleeve arranged to provide a first fine gap between an inner peripheral surface thereof and an outer peripheral surface of the fixed shaft, a fixed sleeve arranged to provide a second fine gap between an inner peripheral surface thereof and an outer peripheral surface of the rotary sleeve, a holder member arranged to cooperate with a lower end surface of the rotary sleeve to provide a third gap, and wherein the first fine gap and the second fine gap are formed with radial dynamic pressure producing grooves while the third fine gap is formed with a thrust dynamic pressure producing groove, the first, second and third fine gaps being filled with lubrication oil, the first fine gap and the second fine gap having one ends made as opening ends contacting with the air and the other ends made as closed ends communicated with each other through the

Abstract: A positive and negative rotation gas dynamic pressure bearing comprises a stationary bearing member, a movable bearing member mounted for rotation relative to the stationary bearing member, dynamic pressure generating grooves having first and second ends and formed in one of confronting surfaces of the stationary bearing member and the movable bearing member, a self-switch valve connected to the movable bearing member for rotation therewith, and conducting holes having first and second ends and formed in the movable bearing member. During rotation of the movable bearing member in a first direction of rotation, a high dynamic pressure is generated at central portions of the dynamic pressure generating grooves, and a valve body of the self-switch valve moves toward a lower space of a valve case of the self-switch valve to close the second ends of the conducting holes.

Abstract: A grinding machine comprises a grinding member having a thickness greater than 10 mm and an outer contact surface extending in a thickness direction of the grinding member for contacting a surface of a workpiece. The grinding member is supported by a first rotational shaft for rotation about a first rotational axis. A first moving mechanism reciprocates the first rotational shaft along a first displacement axis. The workpiece is supported by a second rotational shaft for rotation about a second rotational axis perpendicular to the first displacement axis and the first rotational axis. A second moving mechanism moves at least one of the workpiece and the grinding member along a second displacement axis to bring the outer contact surface of the grinding member into linear contact with the surface of the workpiece to grind the workpiece. The linear contact between the outer contact surface of the grinding member and the surface of the workpiece has a contact length greater than 10 mm.

Abstract: A magnetic bearing device comprises a rotor, electromagnets, radial direction displacement sensors, and a control circuit for controlling an exciting current of the electromagnets in accordance with a signal from the radial direction displacement sensors to magnetically levitate the rotor. The control circuit comprises a position detecting circuit, a calculator, a PID operating part, a phase inverter and power amplifiers. A CPU analyzes the displacement of the rotor at the time of rotation on the basis of a sensor signal issued from the position detecting circuit to supply a correction signal obtained as a result of analysis to the calculator. A magnetic force is thus generated which offsets the oscillation of the rotor for each of the frequency components and is supplied to the electromagnets. The magnetic bearing device is capable of inhibiting displacement components of the rotor other than a first order component in the rotation frequency of the rotor.

Abstract: A grinding machine comprises a table movably disposed on a fixed base to undergo reciprocal movement relative to the fixed base along a reciprocating axis. A first shaft is rotatably disposed on the table to undergo rotation relative to the table about a first axis extending perpendicular to the reciprocating axis. A workpiece holder is connected to the first shaft for rotation therewith. A workpiece having a work surface is connected to the workpiece holder for rotation therewith. A second shaft is rotatably supported for rotation about a second axis extending at an inclination angle to the first axis, and is supported for reciprocal movement towards and away from the workpiece along the second axis. A grinder having a grinding surface is connected to the second shaft for rotation therewith and for reciprocal movement of the grinding surface towards and away from the work surface of the workpiece.

Abstract: An electrolytic combined processing machine includes a grinding wheel spaced apart from and facing a workpiece, a current switching circuit for switching a coarse grinding to a fine grinding of the workpiece by the grinding wheel, and an infeed switching circuit for switching the infeed speed of an infeed table which allows the grinding wheel to relatively approach the workpiece. The switching operation is based on a measurement result obtained from a size measuring unit which measures a processing amount of the workpiece. During fine grinding, the infeed speed of the grinding wheel is the same as the speed of a passivation coating film generated on the workpiece. Workpieces, particularly of brittle materials, can be processed in a state of less processing distortion with improved surface roughness, flatness and efficiency.

Abstract: A damper device for a motor having a boss section attached to a rotary shaft of the motor, a mass inertia section rotatably supported by the boss section such that it surrounds the outer periphery of the boss section with a gap left therebetween, a magnetic fluid filling up the gap, and magnets provided in either the boss section or the mass inertia section for preventing leakage of the magnetic fluid. Furthermore, the boss section and the mass section facing each other through the gap are made of materials differing in the coefficient of thermal expansion, even if the magnetic fluid is heated by heating of the motor, an external temperature variation and the like so that its viscosity is decreased, such a decrease in viscosity can be canceled out by a change in gap dimension caused by the difference in expansion between the boss section material and the mass section material differing in the coefficient of thermal expansion.

Abstract: A clamp mechanism for disks is provided with a clamp body having a reference surface for use in fixing a disk thereon, a plurality of claws adapted to press the disk, which is placed on the reference surface of the clamp body, against the same reference surface and fix the same thereon, a plurality of clamp members which have the claws attached thereto, and which are adapted to be moved vertically in the interior of the clamp body, and cams adapted to turn the clamp members in the radial direction of the disk while the clamp members are vertically moved, in such a manner that the claws come toward one another or go farther away from one another. Each of the claws is formed generally to the shape of a fan. Therefore, the clamp portions of the claws which contact the disk, can press about 70-80% of the total area of the circumferential portion of the central hole in the disk.

Abstract: A damper device for a motor having a boss section attached to a rotary shaft of the motor, a mass inertia section rotatably supported by the boss section such that it surrounds the outer periphery of the boss section with a gap left therebetween, a magnetic fluid filling up the gap, and magnets provided in either the boss section or the mass inertia section for preventing leakage of the magnetic fluid. Furthermore, the boss section and the mass section facing each other through the gap are made of materials differing in the coefficient of thermal expansion, even if the magnetic fluid is heated by heating of the motor, an external temperature variation and the like so that its viscosity is decreased, such a decrease in viscosity can be canceled out by a change in gap dimension caused by the difference in expansion between the boss section material and the mass section material differing in the coefficient of thermal expansion.

Abstract: A hard disk testing apparatus is comprised of a pair of carriages, each provided with a pair of upper and lower heads, and one of the upper and lower heads on either of the carriages is mounted on a micro adjustment carriage. With this structure, the head mounted on the fixed carriage writes a signal, and the head mounted on the carriage equipped with the micro adjustment carriage reads the signal. The structure and operation of the apparatus effectively prevent omission or duplication of testing tracks at the border between a test range of a hard disk covered by one of the pair of carriages and another test range covered by the other carriage.

Abstract: The present invention provides an inspection apparatus for inspecting an object such as an information storage medium or an information recording/reproducing head under set inspection conditions, which comprises: a sensor for identifying the type of object set for inspection by its size, and automatic inspection condition setting means for automatically setting the inspection conditions for the object to be inspected which are associated with the type identified.

Abstract: A magnetic disc clutch mechanism comprises a housing for receiving a cartridge in which a magnetic disc is rotatably disposed. The housing has a base, an opening, and a door movable to close and open the opening. A spindle assembly is slidably mounted on the base under the cartridge, and the spindle assembly is movable upward to contact the magnetic disc for rotatably holding the magnetic disc and is movable downward for releasing the magnetic disc. A lever is disposed on the base, one end of the lever being connected to the door and the other end thereof being movable back and forth relative to the spindle assembly according to the opening and closing movements of the door. An arm extends from the spindle assembly and cooperatively engages with the other end of the lever so that the spindle assembly moves forward when the door is closed and the spindle assembly moves backward when the door is opened.

Abstract: A grinding machine control system has a position detecting device for generating a position signal indicative of the position of a cutting table which is driven at a variable speed by a cutting motor during a grinding process, and a size measuring device for intermittently measuring the workpiece size. A grinding stone table is reciprocally movable relative to the cutting table and carries a grinding stone for grinding the workpiece. A cutting table position signal and a cutting speed signal are intermittently measured under the control of a timing signal which is synchronized with the period of reciprocation of the grinding stone table during the grinding process and are temporarily held as sampling signals. A transient cutting residual amount signal g.sub.0 is obtained by subtracting the workpiece size signal from the sampled cutting table position signal, an error cutting residual amount signal g.sub.3 is obtained by subtracting the standard cutting residual amount signal g.sub.

Abstract: A spindle device comprises a spindle housing having rotatably mounted therein a hollow tubular spindle and a rotary motor for rotationally driving the spindle. One end of the spindle projects outwardly of the housing, and the other end of the spindle is disposed within the housing. A lubricating oil system flows oil through the hollow spindle to the work tool and the system includes an oil conduit which extends a predetermined extent into the interior of the hollow spindle at the spindle other end with a small clearance between the conduit and the spindle. A helical recess is formed on the outer periphery of the oil conduit, or the inner periphery of the spindle, or both, in the region where the oil conduit extends into the spindle so that during high speed rotation of the spindle, a helical airflow is created in the region where the lubricating oil enters the spindle to prevent the outflow of oil from the spindle other end.