Abstract: In a preferred embodiment, a threaded rotor for a linear actuator, including: a generally cylindrical, metallic shell/insert (20); and a generally cylindrical threaded thermoplastic member (72) disposed in a wall of the generally cylindrical shell/insert, the threaded thermoplastic member having threads formed on an inner surface thereof and engagable with complementary threads formed on an outer surface of a shaft to be inserted in the generally cylindrical shell/insert.

Abstract: In order to provide a reciprocating motor which is able to ensure and to be compacted since an outer stator or an inner stator are laminated as a ring type, and fabrication processes thereof are simple and fabrication cost can be reduced, there is provided a reciprocating motor comprising an outer stator in which winding coil is wound; an inner stator disposed on an inner circumferential surface of the outer stator with a predetermined air gap therebetween; and a magnet disposed between the outer stator and the inner stator to perform linear reciprocating movements and fixed on a magnet paddle, wherein the inner stator are formed by laminating a lamination having a predetermined thickness as a ring shape.

Abstract: A linear electromagnetic machine for generating a force acting between two members relatively movable along an axis, one of which is capable of producing a magnetic field the direction of at least part of which extends substantially radially of the said axis and the other of which comprises or includes a conductor, conveniently in the form of a coil, in which an electric current can flow substantially perpendicularly of the magnetic field so as to generate a force between the two members substantially parallel to the axis. The radial magnetic field is generated by permanent magnets orientated with their direction of magnetisation axially, the pole pieces acting to concentrate the magnetic flux to follow a radial path through the coils.

Abstract: A linear brushless electric motor (10) including a magnet component (12), a conductor component (14) that interacts with the magnet component (12) and a control system (15) for directing current to the conductor component (14) is provided herein. Uniquely, the conductor component (14) includes an auxiliary conductor array (42) that reduces stray magnetic fields generated by the electric motor (10), without significantly influencing the dynamic performance of the motor (10) and without significantly increasing the size of the motor (10). Because of the conductor component (14) provided herein, the motor (10) is particularly useful in manufacturing, measurement and/or inspection processes that are sensitive and/or influenced by stray AC magnetic fields. More specifically, the present invention is particularly useful with an exposure apparatus (18) that utilizes an illumination system (24) that generates a charged particle beam, such as an electron beam.

Abstract: A coil construction for a voice coil motor is disclosed. The coil construction includes a series of stacked planar coils disposed on a substrate material. Each planar coil is separated from its neighboring coil or coils by a viscoelastic material to reduce vibration of the coil construction. The coil construction is attached to an actuator arm. Control circuitry creates a current in the coil construction to position a head on the actuator arm. Also disclosed is a method for making a coil for a voice coil motor. The method includes the steps of masking a substrate having a conductive layer with a photoresist, exposing the mask to create a pattern of planar coils, developing the photoresist, and etching the conductive layer to create a planar coil.

Abstract: A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other and having a critical angle of displacement from a horizontal static position of less than 1 degree, to induce an electrical signal in one or more surrounding coils. The magnets interact with each other to yield multiple modes of oscillation and a greater range of response to applied inputs than is achievable with a single magnet system. A lubricant for the magnets is preferably a ferrofluid that establishes a static coefficient of friction between the magnets and their support structure less than about 0.02, with a viscosity less than 10 centipoise. The magnets can be oriented for movement in a primarily horizontal direction and are adaptable to numerous different kinds of support structures, including ring-shaped.

Abstract: A linear driving device of compact size capable of fundamentally canceling a reactive force produced in acceleration and deceleration of a slider within the linear driving device. A slider and a stator constitute a linear motor. The stator is supported to move linearly on the base by an air bearing and the slider is supported to move linearly on the stator. When the slider is driven by the stator to move in one axial direction, a reactive force is exerted on the stator in an opposite axial direction to move the stator in the opposite direction, so that substantially no force is transmitted from the stator to the base. A ratio of weights of the stator and the slider is lopsided so that motion strokes of these members are different. Since the reactive force produced in acceleration and deceleration is canceled within the linear driving device and is not transmitted to the base, any undesirable effect is caused outside of the linear driving device.

Abstract: A method and apparatus for controlling acoustic noise generated by a seek operation in a disc drive by using a feedback control system to control the seek operation. The feedback control system is excited by a feed-forward signal during execution of the seek operation. An acoustic factor, which defines a seek operation noise level, is selected. The feed-forward signal is generated based, at least in part, upon the selected acoustic factor. The feed-forward signal has a first derivative having a maximum value. The selected acoustic factor is used to select the maximum value of the first derivative of the feed-forward signal.

Abstract: An electromagnetic actuator having stationary and movable elements. The actuator includes a magnet arranged on one of the stationary and movable elements, a coil arranged on the other one of the stationary and movable elements, a first coolant channel formed near the coil, and a second coolant channel formed in or near a surface of at least one of the stationary and movable elements. The first coolant channel and the second coolant channel are formed between the coil and the surface or in the surface.

Abstract: A linear actuator includes a plurality of sub-modules disposed in adjacent array and adapted to translate reciprocally parallel to a common axis. A plurality of shape memory alloy wires extend generally linearly and parallel to the axis, and are each connected from one end of a sub-module to the opposed end of an adjacent sub-module. The SMA wires are connected in a circuit for ohmic heating that contracts the SMA wires between the sub-modules. The sub-modules are linked by the SMA wires in a serial mechanical connection that combines the constriction stroke displacement of the SMA wires in additive fashion to achieve a long output stroke. Moreover, the sub-modules are assembled in a small volume, resulting in an actuator of minimal size and maximum stroke displacement.

Abstract: A method for making a stator of a brushless direct current motor, includes the steps of: winding a coil set to predetermined turns, thereby forming a ring body having a central hole, and performing an insulation process; mounting at least two pole plates on two end faces of the coil set respectively, the pole face and the magnetically conducting plates of each pole plate encompassing the inner and outer periphery of the coil set respectively, and a wiring head of the coil set being drawn outside of the pole plate; and mounting a combination member on the magnetically conducting rings (or plates) of each pole plate, thereby forming a stator. The pole faces of each pole plate may be induced with the permanent magnet of the rotor.

Abstract: A system for manipulating a planar substrate such as a semiconductor wafer is provided. The manipulator is typically used in conjunction with an XY stage to focus and planarize a wafer with respect to a tool. The manipulator employs redundant actuators of different types and a control system that uses low-bandwidth, high efficiency actuators to provide low frequency forces and high-bandwidth, but less efficient, actuators to provide all other forces. The manipulator provides support and manipulation of a substrate while minimizing errors due to thermal distortion.

Abstract: In a preferred embodiment, linear stepper motor, comprising; an annular stator structure; an axially extending, cylindrical, permanent magnet shaft extending coaxially through said annular stator structure; and the axially extending, cylindrical, permanent magnet shaft having a smooth external surface along a portion thereof with axially alternating N and S poles defined circumferentially in an outer periphery of the portion of the axially extending, cylindrical, permanent magnet shaft. The present invention also provides a method of magnetizing the shaft of such a motor and a fixture and method of manufacturing the fixture therefor.

Abstract: An electric actuator having an in-line rotation shaft, electric motor and encoder in which the encoder shaft, the motor shaft and the rotation shaft is concentric and integrally formed.

Abstract: A linear motor having an air bearing integrally is disclosed. The linear motor includes a “U” shaped frame having permanent magnets spaced from each other on its inner walls, an inverted “U” shaped frame spaced from outer walls of the “U” shaped frame at interval, having an extension frame for protecting the “U” shaped frame and having air injection openings for injecting air into both ends of a center frame, and an armature coil portion installed on the bottom surface of center frame and spaced from the permanent magnets at interval. Accordingly, a step difference between heights generated when the air bearing and the linear motor are installed, can be removed, and the linear motor can be cooled using the air applied to the air bearing.

Abstract: An apparatus for operating a magnet vehicle, especially a magnetically levitated vehicle. The apparatus includes a long stator linear motor with at least one long stator winding laid along a track and at least one exciter arrangement cooperating with this winding and mounted on the vehicle. The long stator winding is divided into winding sections (5.4, 26.4) following one another, which each have a greater length than the exciter arrangement. At least two section cables serve to supply the winding sections with electric power and switch devices serve to connect the winding sections (5.4, 26.4) sequentially to a section cable each in correspondence with the progression of the vehicle. In accordance with the invention the winding sections (5.4, 26.

Abstract: A linear motor has an armature; a moving member movable relatively to the armature; first and second magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to one of two magnetic poles of the moving element, the first and second magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member; and third and fourth magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to the other of the two magnetic poles of the moving element, the third and fourth magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member and the moving member being arranged between the first and second magnetic pole tooth trains and the third and fourth magnetic pole tooth trains.

Abstract: A flux-switching linear motor with at least two phases P1, P2, P3 has a moving rig, two permanent magnets 9, 10 and a switching mechanism. The moving rig 1 has at least two field coils 7. Each field coil 7 surrounds a magnetic armature 8 defining moving magnetic poles. The two permanent magnets 9, 10 are magnetized in opposite directions, transverse to the axis of a guidance stator tube 1. The stator tube 1 has magnetic poles 2 disposed along at least one of its walls so as to be successively facing the moving magnetic poles during the travel of the moving rig. The switching mechanism switches the direction of the current in the coils. The permanent magnets 9, 10 are disposed outside the coils and magnetized along an axis parallel to the axis of the coil. The stator magnetic poles include pieces 2 made of magnetic material fixed in a guidance tube made of amagnetic material.

Abstract: The present invention discloses a system for non-contact measurement of vibrational motion in a vibratory compacting machine. The system includes a vibrating element such as a roller drum adapted for vibrational motion and a non-contact sensor positioned a distance from the vibrating element and adapted for sensing the vibrational motion of the vibrating element. The present invention also discloses a method for non-contact measurement of vibrational motion of a vibrating element in a vibrating element that includes sensing position information of the roller drum with a non-contact sensor positioned a distance from the vibrating element and determining at least one vibration characteristic based on the position information sensed with the non-contact sensor.

Abstract: Stage apparatus are disclosed that provide high-accuracy positioning and movements of a stage platform, while generating reduced stray magnetic-field fluctuations and perturbations. The stage apparatus include at least one linear motor having a stator and a moving coil. Each stator includes a yoke that includes linear arrays of permanent magnets relative to which the moving coil, attached to the stage platform, moves inside a linearly extended coil gap in the yoke. A magnetic-shield plate extends around all outer surfaces and edges of the yoke as well adjacent the coil gap. The magnetic-shield plate is made of a magnetic material having high magnetic permeability.