Abstract: In a linear motor, magnetic poles on a stator (or moving element) and teeth on a moving element (or stator) face one another to form a gap. The gap-side surface of each of the magnetic poles or teeth has an external shape represented by a hyperbolic function or a reciprocal function of cosine. Thus, the cogging torque can be made lower than that of a conventional linear motor of which the magnetic poles (permanent magnets) or teeth have an external shape represented by a straight line, circular arc, parabola, or hyperbola.

Abstract: A moving body drive unit includes a linear motor for imparting linear motion to a moving body, guide elements for non-contact guiding of the moving body with respect to a support body, a long scale (42) etched with gradations, a read head (41) for detecting position of the moving body by reading gradations of the scale without contacting the scale, a scale housing body (44) for housing the scale and the read head, attached to one of the moving body or the support body, and a scale cover (47), attached to the other one of the moving body or the support body. The scale housing body has an elongated opening (45) through which one of the scale or the read head can be inserted into the scale housing body, and a supply port (46) for introduction of compressed air. The scale cover forms an air chamber (49) sealing the elongated opening of the scale housing body in a non-contact manner with a microscopic gap (48).

Abstract: A linear motor includes a coil unit and a magnet unit. The coil unit includes an inner yoke extending in a moving direction and a coil arranged outside the inner yoke. The magnet includes a magnet arranged outside the coil. Each of the inner yoke, coil, and magnet includes a plurality of flat portions, the plurality of flat portions of the inner yoke are parallel to an axis of the coil. Each flat portion of the inner yoke is parallel to the corresponding flat portion of the coil and the corresponding flat portion of the magnet. A length of the inner yoke in a direction along the axis of the coil is longer than a length of the magnet in the direction along the axis of the coil, and the inner yoke has a prismatic structure formed by the plurality of flat portions supported by a support member.

Abstract: A linear 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) minimizes the total stray magnetic fields generated by the conductor component (14), without significantly influencing the dynamic performance 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: An apparatus and method are provided for attenuating vibration when driving an object. The apparatus includes a driving device for generating a driving force to drive the object and an attenuation actuator mounted in reciprocal relationship with the driving device for generating an attenuation force substantially concurrently with the generation of the driving force. The attenuation force is generated so as to oppose and at least partially cancel a reaction force exerted by the object in response to the driving force.

Abstract: A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other for individual movement relative to a support structure. The magnets have a critical angle of displacement from a horizontal static position of less than 1 degree, with at least some of the magnets having mutually different properties. With different magnetic strengths, a greater movement is produced for both magnets in response to movements of the support structure, for particular ranges of magnetic strength ratios, than would be the case with equal magnets. The magnet movement can be translated into an electrical signal to power an operating system. Ultra low friction ferrofluid bearings can be used to establish static coefficients of friction between the magnets and support structure less than 0.02, enabling useful power generation from only slight movements of the support structure.

Abstract: A voice coil linear actuator comprises: an axially-shaped center yoke formed of a ferromagnetic material; an armature coil concentrically disposed so as to move along the axial direction of the center yoke; and a plurality of ring-shaped permanent magnets which have N and S magnetic poles arranged in the radial direction thereof, and are disposed concentrically as to the armature coil. The armature coil has armature coil units distributed in at least three positions in the axial direction, with adjacent pairs of the armature coil units being arranged so that electric current flows through them in opposite directions, respectively. The permanent magnets are distributed in at least three positions in the axial direction at positions facing respective armature coil units in the radial direction. The respective directions of the N magnetic poles of adjacent permanent magnets are arranged facing in opposite directions.

Abstract: A device for winding, at high speed, a yarn onto a rotating support comprises a yarn delivery system, displaced so as to undergo a to-and-fro movement parallel to the surface of said support with rapid deceleration and acceleration at the point of reversal of the to-and-fro movement. A depositing yarn guide of the delivery system is displaced by means of a moving element or cursor associated with a magnetized plate of a linear motor, supplied with two-phase or three-phase current. The stator is formed by at least one assembly of elementary modules placed either face to face or placed so that each lies in the extension of another, each having a plurality of C-shaped magnetic circuits that define, between the ends of their separated legs, an airgap inside which the magnetized plate is positioned, comprising an alternation of North and South poles (N and S), which constitutes the moving element that displaces the cursor carrying the yarn guide.

Abstract: In a stator core having a plurality of teeth, which elongate in an inner radial direction and slots, which are configured among the teeth, powder is caused to adhere to the stator core, the powder adhering to an inner peripheral face of the stator core is removed, and the stator core is heated to melt and harden the powder.

Abstract: A linear actuator includes a first yoke part, a second yoke part opposing the first yoke part from a direction perpendicular to the axial direction thereof, an intermediate yoke part forming a first gap and a second gap, a coil disposed within a space delineated by the intermediate yoke part and the second yoke part, which forms a magnetic field between the first yoke part and the intermediate yoke part. The orientation this magnetic field is opposite between the first gap and the second gap, and orientation thereof alternates. The actuator further includes a magnet at one axial-direction end relative to the coil, which generates a fixed magnetic field in the two gaps, directed either from the intermediate yoke part toward the first yoke part or from the first yoke part toward the intermediate yoke part, and an armature disposed that is movable in the axial direction in the first gap and the second gap.

Abstract: A ripple suppressor/compensator useful in the general area of motion control and applicable to a wide range of servomechanisms exhibiting a force ripple characteristics, including the permanent magnet linear motors. An adaptive feed-forward control signal is generated which compensates for the ripple force, thus allowing for more precise tracking performance to be achieved.

Abstract: A linear pulse motor includes primary stators (1) in which a plurality of excitation units (3a-3d) and excitation coils (5a-5d) wound on the excitation coils are lined up in a row, and a secondary movable element (12) arranged at a predetermined gap from the stators (1) to face side surfaces of the stators (1). The stators (1) are arranged in a traveling direction of the movable element (12), and the stators (1) and the movable element (12) are supported to be movable relative to each other in the traveling direction of the movable element (12). A plurality of pole teeth (16) arranged on the movable element (12) are partitioned and integrally connected to each other by a nonmagnetic member (17). The secondary movable element is made lightweight and the response performance is improved.

Abstract: Drive devices for switchgear interrupter units, having movable contact pieces that can be controlled by solenoid drives are described. The drives of the movable contact pieces being controllable by linear motor drives. The interrupter units are realized by vacuum circuit breakers, and the linear motor drives are realized by three-phase AC linear motors. Each of these can be influenced by a control unit that optimizes the switching operations and that is provided with a mains connection. The three-phase AC linear motors are composed of individual components that determine thrust and range of motion. The individual components together constitute the drive of the movable contact parts. The individual components are determined by the number of motor coils and/or by the number of parallel motor modules.

Abstract: A linear motor includes a plurality of electromagnetic coils continuously arranged and a magnet assembly disposed such that it may travel due to the interaction between itself and the magnetic fluxes from the coils. The coils include U, V, and W phase coils in star connection. The coils of the individual phases are installed in series around a hollow-shaft center core over the travel range of the magnet assembly such that the magnetic pole axis thereof is oriented in the same direction as the axis of the center core. The magnet assembly has an annular shape so that it may surround the coils, and is formed of a plurality of permanent magnets. The magnets are combined in series such that the same magnetic poles oppose each other and the magnetic pole axis is oriented in the same direction as the axis of the center core.

Abstract: Linear motor and method to make the same. The motor comprises an armature equipped with compartments (15) inside which are housed electric coils (16), and two fixed bars (22) cooperating with respective sides of the armature, on each of which are mounted permanent magnets (12) arranged facing said electric coils (16). The armature (14) is made mainly of aluminium or of ceramic material. The armature (14) comprises interruptions (21) defining zones of electric discontinuity in cooperation the perimeter of the compartments (15) housing the coils (16).

Abstract: Electric equipment is provided for mounting on vehicles and electrical machines having superior rust-prevention film, which makes it possible to prevent vehicles from generating red rust even if outer surface of magnetic core housing of the vehicle is damaged by bouncing a stone and the like during running, and also to provide manufacturing methods of the same. Any outer surface and surface exposed outward of the magnetic core housing is coated sequentially with a metal plated layer or an alkali zinc plated layer, chromate film or zinc phosphate film, and organic resin coating.

Abstract: Reaction force transfer system includes a frame and a machine base supported by the frame through passive isolation structure. A carriage is supported for motion with respect to the machine base and a motor is provided having a stator coupled to the frame and a forcer coupled to the carriage to move the carriage with respect to the machine base.

Abstract: In a reciprocating device having a moving element, a stator and a flexing suspension for coupling the moving element and stator and for maintaining the moving element on axis, the flexing suspension comprising: at least one flexing element locating the stator relative to the moving element by directly engaging features of the flexing element to mating features of the stator.

Abstract: Methods and apparatus for adjusting a push point of an actuator such that the push point more closely corresponds to a center-of-gravity of a stage being driven by the actuator are disclosed. According to one aspect of the present invention, a method for scanning a stage device which includes a stage, as well as an actuator which has a first coil and a second coil, includes driving the stage using the actuator and determining when driving the stage using the actuator includes driving the stage through a first location associated with the stage. The actuator is arranged to drive the stage through a push point associated with the first coil and the second coil. The method also includes altering the push point when it is determined that driving the stage using the actuator does not result in the stage being driven through the first location associated with the stage.

Abstract: In a reciprocating motor capable of securing a stability of a motor by improving a strength of a magnet frame, preventing breakage of the magnet frame in operation of the motor and preventing an inner stator from rotating and separating from a support frame, the reciprocating motor includes an inner stator locker installed between the inner stator and the support frame and preventing the inner stator from separating from the support frame and a magnet frame having plural support bars formed at regular intervals so as to form a space portion in which the magnet is installed in the circumference direction.