Abstract: A fluid bearing design is provided which according to one aspect includes a shaft defining together with a surrounding sleeve an asymmetric journal bearing, and a thrust bearing at or near an end of the shaft towards which the asymmetric journal bearing is pumping, with that end of the shaft being closed off. The journal bearing asymmetry establishes a hydraulic pressure toward the closed end of the shaft. This pressure provides an axial thrust to set the bearing gap for the conical bearing. The conical bearing itself is a relatively balanced bearing, although it may have a bias pumping toward the shaft and the journal bearing. A pressure closed equalization path from the journal bearing through the conical bearing to the end of the shaft may be established to maintain a constant hydraulic force across the conical bearing, and which may also prevent any asymmetry in the conical bearing from affecting the net thrust force acting upon the end of the shaft where the conical bearing is located.

Abstract: A high precision laser machining apparatus having a horizontal translation axis (z-axis) and a rotary axis (theta-axis) parallel with the translation axis comprises parallel spaced apart linear translation stages, a carriage supported between the parallel translation stages, and a rotation stage carried by the carriage between the parallel translation stages. Mounted on the same base plate is a laser optics support stage and a workpiece advance mechanism.

Abstract: An electric machine having multi-set rectangular copper hairpin windings comprises a stator having a plurality of partially closed stator slots. A first winding set and a second winding set are positioned in the stator slots. The first winding set and the second winding set are connected by adjacent leg ends. According to a first embodiment, conductor layers in alternate slots alternate between different phases. The conductor layers in the remaining slots are all of the same phase. Hairpins having unequal length legs are used to implement the first embodiment. According to a second embodiment, conductor layers in alternate slots include one phase for the first winding set and another phase for the second winding set. The conductor layers in the remaining slots are all of the same phase. Hairpins having equal length legs are used to implement the second embodiment.

Abstract: A magnetic drive for providing pivotal motion to a functional surface, such as a mirror. The magnetic drive may be used to drive any torsional hinged device, but is particularly suitable for driving a torsional hinged mirror. According to a first embodiment, a dual axis functional surface uses a first pair of torsional hinges to provide primary movement to the functional surface and a second pair of torsional hinges provides movement orthogonal to the primary movement to allow positioning in two directions. The mass and movement of inertia of the functional surface is reduced by relocating permanent magnet sets to the axis of rotation. The reduced mass and movement of inertia results in a stiff robust hinge having a resonant frequency above about 120 Hz.

Abstract: A stage assembly (220) for moving a device (200) includes a stage (208), an attraction-only type actuator pair (426) that moves the stage (208), and a control system (24). In one embodiment, the actuator pair (426) includes a first electromagnet (436F), a first conductor (438F) and a first target (440F) having a first target surface (442F). The actuator pair also includes a second electromagnet (436S), a second conductor (438S) and a second target (440S) having a second target surface (442S). The first electromagnet (436F) is positioned at a first angle ?1 relative to a first target surface (442F) and the second electromagnet (436S) is positioned at a second angle ?2 relative to the second target surface (442S). The control system (24) directs a first current to one or more of the electromagnets based on at least one of the angles ?1, ?2. Further, one or more electromagnets (436) can include a first measurement point and a second measurement point.

Abstract: A position-control stage is disclosed which makes it possible to extend largely an angular movement in circular direction for position control, rendering the stage itself compact in construction, allowing to work with high precision in clean environment and further produce the stage with inexpensive cost. The position-control stage has an onboard linear motor composed of armature windings of primary side and field magnets of secondary side. The armature windings are each made in a hollow rectangle where winding turns are wound in the form of flat loop, and are circularly arranged on a disc surface of the bed along a preselected curvature in such a way lying in radial juxtaposition in circumferential direction. The field magnets are made in a flat shape and arranged underneath the turntable in such a pattern lying radially on a disc surface of the preselected curvature in opposition to the armature windings, with their unlike poles alternating in polarity along a circular direction.

Abstract: An electric motor operated by AC current, that includes a stator and a rotor supported for rotation about an axis relative to the stator. The stator is provided with field windings angularly distributed about the rotor axis and capable of producing a magnetic field vector in the space of the rotor. Circuitry delivers AC current to the windings in a manner that produces an AC magnetic field vector that moves around the axis of the rotor. The rotor has a construction, such as an axially extending conductive loop, that changes its reluctance in the AC magnetic field depending on its orientation to the AC magnetic field vector whereby the rotor is caused to rotate in synchronization with the movement of the AC magnetic field vector.

Abstract: An electrodynamic actuator has a permanently magnetic stationary part that forms an air-core with a magnetic field, and an armature with a coil arranged in the air-core. The armature moves in the magnetic field in the air-core dependent on a drive current fed to the coil. An increased accuracy is achieved by the provision of damping in relation to the speed of the armature, by arranging a sensing winding on the armature and connecting a calculation unit to the sensing winding. The calculation unit determines the speed of the armature from an induced voltage in the sensing winding caused by a movement of the armature in the magnetic field.

Abstract: The present invention provides a linear motor and glide assembly for mounting a linear motor employing a unitary bearing rail structure and further providing heat compensation and compensation for thermal expansion, with further compensation provided to substantially reduce cogging.

Abstract: A vibrating device has an axially elongated frame, and a vibrating assembly including a hollow yoke. A magnetic driving device is provided for axially vibrating the vibrating assembly. A supporting shaft is provided for axially slidably supporting the vibrating assembly in the frame.

Abstract: A linear motor system including compartmentalized stator sections provides an interchangeable and serviceable alternative to other linear motors. The stator sections may be individually-energized so that power is only sent to stator sections adjacent to the thrust plate or rotor of the linear motor. A sufficiently long thrust plate is used to cover any gaps in the linear stator, and additional compensation stator sections are used to provide additional motor force to the thrust plate adjacent to these gap sections. If utilized onboard a ship, additional compensation stator sections may be incorporated into the face of deck hatches. The linear motor system can also be used to counteract gravitational effects in a large hanging door system implementation.

Abstract: The present invention discloses a control apparatus for a vibration type actuator that can perform the drive of a driven member in a short time. The control apparatus for a vibration type actuator that excites vibration in a vibration body by applying a frequency signal to an electro-mechanical energy converting element and relativity moves the vibration body and a contact body contacting to this vibration body includes a determination unit determining the drive direction of the vibration type actuator, and a frequency setting unit modifying a frequency of the frequency signal according to whether the drive direction of the vibration type actuator determined by the determination unit is the same as or reverse to the last drive direction at the startup of the vibration type actuator.

Abstract: The present invention provides an electromagnetic drive motor assembly (EDMA) that has an inner flux return assembly formed from an upper pole piece and a lower pole piece oppositely disposed relative to each other along the center of the EDMA. An annularly positioned conductive ring (or flux stabilization ring) encircles the inner flux return assembly, concentrically in contact with the outside of the inner flux return assembly. Along the exterior side of the flux return pieces, is a magnet that is between a top plate and a bottom plate. Each plate contacts with the magnet to form a magnetically conductive system. A magnetic gap is formed in between the inner flux return assembly and the top and bottom plates. Disposed within the magnetic gap is a dual coil wound around a cylinder. The dual coil includes a first coil portion and a second coil portion. To minimize the modulation, the top and bottom plates may be saturated and plate tips may be provided near the magnetic gap.

Abstract: An apparatus for driving a linear vibration motor that employs a proper motor thrust constant value corresponding to each linear vibration motor at position calculation for obtaining the position of the mover of the linear vibration motor, thereby increasing the accuracy of the position calculation. This motor driving apparatus includes a motor driver for applying a DC voltage to the linear vibration motor, and a thrust detection unit for detecting a thrust of the mover, which is generated by the application of the DC voltage to the linear vibration motor, and calculates the thrust constant of the linear vibration motor according to an arithmetic operation of dividing the mover thrust detected by the thrust detection unit, by a value of a DC current that is supplied to the linear vibration motor due to the application of the DC voltage to the linear vibration motor.

Abstract: A vibration generator system is capable of generating vibrations of a frequency that can be bodily sensed by humans, notwithstanding a small size, and making setting of a configuration of vibrations easy. When a drive signal composed of a set of an accumulation signal and a damping signal is given as a natural frequency of a movable body, a vibrational waveform of the movable body makes an envelope. Since a frequency of the envelope is in a lower frequency band than the natural frequency of the movable body, humans can surely sense vibrations. When the number of and a current quantity of excitation signals and reverse excitation signals included in the accumulation signal are changed and the number of and a current quantity of inhibition signals and reverse inhibition signals included in the damping signal are changed, the envelope can be changed in frequency and amplitude, so that it becomes possible to generate a variety of vibrations.

Abstract: In a motor portion of a linear actuator, a rear end cap and a front end protrusion, which are disposed respectively at the rear and front ends of a stator assembly, and which include rear and front bearings to rotatably support a rotor assembly, are formed by injection-molding simultaneously and integrally with a stator support member which fixedly supports constituent members of the stator assembly, whereby the stator assembly, the rear end cap, and the front end protrusion can be coaxially aligned to one another with a high degree of precision thus improving the assembling precision of the motor portion. Also, since the front bearing can be attached to the front end protrusion before an output shaft is attached, the rotation characteristic of the rotor assembly can be evaluated before the output shaft is attached.

Abstract: The conventional linear drive apparatus has the problem that in constructing a linear motor of a multiphase structure by connecting a plurality of armature units, the length of the armature becomes longer in proportion to the number of the phases, thus limiting the locations where the apparatus can be installed. The problem is solved by a linear drive apparatus comprising a plurality of armature units 3 formed by a magnetic material on which a conductor coil 4 is disposed, and an armature comprising an arrangement of the armature units 3. The armature units 3 comprise a plurality of opposing portions having opposing magnetic pole teeth. The magnetic pole teeth of adjacent opposing portions are arranged in an interdigitated manner. A secondary member 6 is disposed between magnetic pole teeth of the opposing portions. The armature units 3 comprise the coil 4 arranged on opposite sides thereof in an alternating manner.

Abstract: A plain surface stage apparatus includes a platen having a plain surface, stationary type supports comprising at least three supporting members, and displacement type supports, each of which supports the platen and forms a displacement type supporting point at a position other than those of supporting points formed by the stationary type supports, wherein the displacement type supports expand and contract in a direction perpendicular to the plain surface of the platen so as to be displaced, and holds a selected displaced state of the displacement type supports.

Abstract: An apparatus and method for controlling driving of a linear motor, which is configured to increase efficiency of a linear compressor and stably drive the linear motor when the linear motor is overloaded. The apparatus includes a detector that detects a current applied to a motor, a controller that outputs a control signal based on the detected current and a switch that varies the number of windings of the linear motor coil on the basis of the control signal.

Abstract: A magnetic field distribution for a planar motor is described. The magnetic field distribution can either be generated by means of permanent magnets or one or more current carrying conductor. The planar motor can be applied in a lithographic apparatus for displacing an object table along a first direction and a second direction perpendicular to the first direction. The particular arrangement of permanent magnets or current carrying conductor(s) may result in an improved efficiency of the planar motor in one of said first or second directions.