Abstract: A polishing apparatus comprises a polishing member for polishing a workpiece and a manipulator for manipulating the workpiece and having a base disposed at a coordinate origin of a base coordinate system. The polishing member and workpiece define therebetween a contact surface having a contact surface coordinate system relative to an initial coordinate system defined when the polishing member and the workpiece initially contact one another at the contact surface but before a force is exerted on the contact surface to polish the workpiece. A first control device successively updates a position and attitude of the contact surface coordinator system with respect to the initial coordinate system on the basis of a deviation between preselected values of force and moment acting on the workpiece and detected values of force and moment acting at the contact surface between the polishing member and the workpiece when a force is exerted on the contact surface to polish the workpiece.

Abstract: As illustrated, a formed grinding wheel dresser 4 is moved toward a formed grinding wheel 2 and is caused to make approach to it up to a prescribed position in the infeed direction thereof. After the formed grinding wheel dresser 4 has approached the prescribed position, the formed grinding wheel dresser 4 is moved rightward in the thicknesswise direction of the formed grinding wheel 2 and thereby determines a position dzl that is attained when having contacted with the formed grinding wheel 2. Next, the formed grinding wheel dresser 4 is moved leftward and thereby determines a position dz2 that is attained when having contacted with the formed grinding wheel 2. A target position X of the formed grinding wheel dresser 4 in the thicknesswise direction is determined based on the thus-determined both positions dz1 and dz2. The current position of the formed grinding wheel dresser 4 is positionally aligned with the thus-determined target position X.

Abstract: A gas compressor has a first chamber for receiving a low pressure refrigerant gas. A main body has a second chamber for drawing in the low pressure refrigerant gas from the first chamber and undergoing a compression operation to compress the low pressure refrigerant gas into a high pressure refrigerant gas. A third chamber receives the high pressure refrigerant gas from the second chamber. A fourth chamber receives a lubricating oil and is subjected to the pressure of the high pressure refrigerant gas from the third chamber. An oil passage has an inlet port opening into the fourth chamber and an outlet port opening into the main body. The lubricating oil from the fourth chamber is supplied to the main body through the oil passage due to a pressure difference between the third chamber and one of the first chamber and the second chamber.

Abstract: A magnetic bearing apparatus comprises a first magnetic bearing for levitating a rotary body by magnetic attraction forces in an axial direction thereof and a second magnetic bearing for levitating the rotary body by magnetic attraction forces in a radial direction thereof. A first detecting device detects axial displacement of the rotary body and outputs a first detection signal corresponding to the detected axial displacement of the rotary body. A second detecting device detects radial displacement of the rotary body and outputs second detection signals corresponding to the detected radial displacement of the rotary body. A first A/D conversion device converts the first detection signal to a first digital signal at a first conversion speed. A second A/D conversion device converts the second detection signals to second digital signals at a second conversion speed different from the first conversion speed.

Abstract: A chuck spindle apparatus comprises a chuck spindle mounted for rotation about a central rotational axis, a chuck main body integrally connected to a forward end of the chuck spindle for rotation therewith, and an indexing device. The chuck main body has a chuck portion for bringing any one of a series of fabrication centers of a workpiece into coincidence with the central rotational axis to thereby chuck the workpiece. The indexing device is disposed within the chuck main body for moving the chuck portion of the chuck main body to bring another one of the fabrication centers of the workpiece into coincidence with the central rotational axis while the workpiece is chucked by the chuck portion of the chuck main body.

Abstract: A method for manufacturing a ferrule for use with an optical fiber connector comprises providing a ferrule blank having a hole for insertion of an optical fiber therethrough between end surfaces of the ferrule blank. A rough grinding operation is performed on the outside diameter of the ferrule blank. Thereafter, the hole of the ferrule blank is polished based on the outside diameter of the ferrule blank which has been subjected to the rough grinding operation. The outside diameter of the ferrule blank is then subjected to a finish grinding operation using a both-center supporting method by bringing a center jig to abut the end surfaces of the ferrule blank and supporting the ferrule blank with the center jig from the end surfaces of the ferrule blank.

Abstract: This invention relates to a switched reluctance rotator according to which a rotor can be rotated at a high speed without generating electromagnetic vibration at a rotating shaft and in which a current for generating of torque and a current for generating a radial force are passed through windings on the protruding poles of the stator or a winding for generating torque, and a winding for generating a radial force are wound on the protruding poles of the stator.

Abstract: A spindle motor comprises a rotational member supported by bearings for rotation about a rotational axis, a rotational body and a motor rotor mounted on the rotational member for rotation therewith, and a motor stator mounted around the motor rotor. The rotational body has an outer diameter determined so that a windage loss of the rotational body is proportional to the third power of a peripheral velocity of the rotational body and an air gap diameter of the bearings and the diameter of the motor stator are determined so that the air loss of each of the bearings and the motor rotor is proportional to the square of the peripheral velocity of each of the bearings and the motor rotor at a range of constant speed of rotation of the rotational member.

Abstract: A vacuum-oriented vertical transfer system which provides super vacuum/super clean environments, and a gate valve assembly which reduces the size of electromagnet sections. The vacuum-oriented vertical transfer system includes a cylindrical partition wall, and a rod vertically moved through an open bottom of a vacuum container. The rod is floatingly supported in radial and axial directions thereof by a radial magnetic support device and an axial magnetic support device, respectively. The gate valve assembly comprises a closure member mounted for positioning adjacent to and away from a port of a container to close and open the port, respectively. A neck member is integrally connected to the closure member and is mounted for movement to position the closure member to open and close the port of the container. A radial magnet device levitates the neck member by magnetic forces in a radial direction thereof. An axial magnetic device levitates the neck member by magnetic forces in an axial direction thereof.

Abstract: A spindle motor comprises a permanent magnet having an outer diameter, an outer circumference, and a number of poles. A stator core is disposed around and spaced from the outer circumference of the permanent magnet rotor. The stator core has a yoke portion, a number of lengthwise extending and circumferentially spaced slots, and a tooth portion between each adjacent two of the slots. The slots are disposed in close proximity to the outer circumference of the permanent magnet rotor, and a width of each of the slots in a radial direction of the stator core is smaller than a width of the yoke portion and equal to or greater than 1/20 of the outer diameter of the permanent magnet rotor. A coil has two or less turns and is comprised of a conductor disposed in the slots of the stator core.

Abstract: A spindle apparatus comprises a main shaft mounted for rotary movement, a rotating device for rotating the main shaft about an axis, a vibration device for vibrating the main shaft, a detecting device for detecting a displacement of the main shaft when the main shaft is vibrated by the vibration device and providing an output signal indicative of the displacement of the main shaft, a calculating device for calculating an allowable revolution speed of the main shaft on the basis of the output signal of the detecting device, and a drive source for driving the rotating device to rotate the main shaft within a speed range which does not exceed the allowable revolution speed. When an end of the main shaft is vibrated by the vibration device, a displacement of the vibrated main shaft is detected by the detecting device which provides an output signal indicative of the detected displacement.

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: The compressor has a cylinder chamber, a control plate provided with an inlet hole, a gas exchange chamber, and gas supply passages. The cylinder chamber is in communication with the gas exchange chamber via the inlet hole in the control plate. The gas exchange chamber is in communication with the outside via the gas supply passages. When the displacement is small, a part of refrigerant gas inside the cylinder chamber is bypassed to the gas exchange chamber from the inlet hole in the control plate. Therefore, great pressure variations are induced in the gas exchange chamber, but the gas exchange chamber is in communication with the outside via the considerably long gas supply passages. These passages mitigate the pressure variations transmitted to the outside. Furthermore, the passages act also as a muffler. Consequently, pressure variations inside the gas exchange chamber are prevented from being transmitted to external piping and so on; otherwise noise would be produced.

Abstract: An orthogonal coordinate type robot comprises a slider and a support frame supporting the slider for movement within a predetermined range along an axis. The support frame has an inner wall surface, at least one hollow portion, and a connecting hole for communicating the hollow portion with the inner wall surface. A suction device evacuates air from the hollow portion of the support frame.

Abstract: An apparatus for measuring a cutting line having a first end and a second end comprises a photographic device for photographing an image signal of the cutting line, and a processing device having a conversion function for converting the image signal of the cutting line into binary image data, first and second contour tracing functions, and a judging function. The first contour tracing function traces the contour of the cutting line from the first end to the second end of the cutting line based on the binary image data and outputs first contour tracing data corresponding to the contour of the cutting line. The second contour tracing function traces the contour of the cutting line from the second end to the first end of the cutting line based on the binary image data and outputs second contour tracing data corresponding to the contour of the cutting line.

Abstract: A dressing apparatus comprises at least two electrode pieces each having an arcuate inner surface and being arranged around a grinding stone to define a gap therebetween. A gap adjusting mechanism adjusts the gap between the arcuate inner surface of each of the electrodes and the grinding stone and maintains the gap between the arcuate inner surface of each electrode and the grinding stone equal to each other.

Abstract: By using a hysteresis amplifier for driving an electromagnet, a highly accurate electromagnetic bearing may be produced without the need for independent position detectors to maintain the levitated position of a rotor constant. In one embodiment, the electromagnetic bearing includes multiple electromagnets for levitating a rotor in a predetermined position. Multiple hysteresis amplifiers each supply a switching signal for driving each of the electromagnets. The switching frequency of the switching signals changes in accordance with the inductance of the electromagnets, which varies in accordance with the relative position of the electromagnets. A phase comparator detects the phase difference between the switching waveforms of each hysteresis amplifier. A loop filter supplies a target current value converted from an output of the phase comparator to the hysteresis amplifiers.

Abstract: A transferring device is provided for transferring an article between vacuum chambers. The transferring device comprises a cylindrical float member, and a transferring rod connected to and extending along an axial direction for supporting an article. At least one magnetic member is disposed on a peripheral surface of the float member. A cylindrical partition member having a thin, uniform circular cross-sectional thickness is disposed between the electromagnet and the float member. A support member is disposed within the partition member for reciprocating movement between opposite ends of the partition member. The support member supports at least one electromagnet and at least one sensor in spaced apart and facing relation with respect to the magnetic member for magnetically floating the float member and to drive the same in the axial direction.

Abstract: A dicing machine comprises a work table having a surface for supporting a workpiece and a processing element for processing the workpiece. A gap detection device detects a preselected gap between the processing element and the surface of the work table. A control device moves the processing element and the gap detection device and detects their positions. A non-contact detection device detects a non-contact condition of the gap detection device and a processing portion of the processing element. A calculating device calculates a processing position of the workpiece in accordance with the positions of the processing element and the gap detection device detected by the control device when the preselected gap between the processing element and the surface of the work table is detected by the gap detection device, and when the non-contact condition of the gap detection device and the processing portion of the processing element is detected by the non-contact detection device.

Abstract: It is intended to provide a table driving device which does not make a machine unduly large, and moves a table with high accuracy without being affected by deflection components of a nut as caused by rotation of a feed screw. The table driving device includes a guide portion with which a part of a table is movably engaged, a driving motor for rotating a feed screw, a nut threadedly engaged with the feed screw that is disposed in parallel with a moving direction of the table, a nut holder having a nut connecting portion connected to the nut and an engaging portion movably engaged with the guide portion, and moving along the feed screw and the guide portion together with the nut in accordance with the rotation of the feed screw, and a coupling mechanism for coupling the engaging portion of the nut holder to the part of the table that is engaged with the guide portion through balls that can roll in planes perpendicular to the moving direction of the table.