Stage apparatus and linear motor, and exposure apparatus and device production method using the stage apparatus
First Claim
1. A linear motor comprising:
- a single-phase coil;
a plurality of polyphase coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil;
a first permanent magnet movable relative to said single-phase coil and said plurality of polyphase coils in an axial direction of said single-phase coil;
a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction;
a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil; and
a second permanent magnet for connecting said first and second yokes.
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Accused Products
Abstract
A linear motor includes a single-phase coil, a plurality of polyphase coils each of which is shorter than the single-phase coil and wound to be parallel to the single-phase coil, a first permanent magnet movable relative to the single-phase coil and the plurality of polyphase coils in an axial direction of the single-phase coil, a first yoke consisting of a ferromagnetic substance and extending through the single-phase coil in the axial direction, a second yoke consisting of a ferromagnetic substance and having, outside the single-phase coil, a portion arranged to be parallel to the first yoke, to form a closed magnetic circuit together with the first yoke and the first permanent magnet such that the closed magnetic circuit circulates magnetic fluxes from the first permanent magnet across a winding of the single-phase coil, and a second permanent magnet for connecting the first and second yokes.
72 Citations
8 Claims
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1. A linear motor comprising:
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a single-phase coil; a plurality of polyphase coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil; a first permanent magnet movable relative to said single-phase coil and said plurality of polyphase coils in an axial direction of said single-phase coil; a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction; a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil; and a second permanent magnet for connecting said first and second yokes. - View Dependent Claims (2, 3, 4, 5)
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6. A linear motor comprising:
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a single-phase coil; a plurality of polyphase coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil; a first permanent magnet movable relative to said single-phase coil and said plurality of polyphase coils in an axial direction of said single-phase coil; a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction; and a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil, wherein said first and second yokes are connected such that the magnetic fluxes generated by the coil current lose the circulation path in the ferromagnetic substance.
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7. A linear motor comprising:
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a single-phase coil used for speed control; a plurality of polyphase accelerating/decelerating coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil for speed control; a first permanent magnet having magnetic poles movable relative to said single-phase coil in an axial direction of said single-phase coil; a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction; a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil; and a second permanent magnet for connecting said first and second yokes, wherein said first permanent magnet is a movable magnet with one of its magnetic poles opposing said single-phase coil, said first and second yokes are fixed yokes each having a straight portion over an entire stroke of said movable magnet, said single-phase coil is wound on said first yoke over the entire stroke of said movable magnet, and said second permanent magnet connects said first and second yokes outside the stroke.
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8. A linear motor comprising:
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a single-phase coil used for speed control; a plurality of polyphase accelerating/decelerating coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil for speed control; a first permanent magnet having magnetic poles movable relative to said single-phase coil in an axial direction of said single-phase coil; a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction; a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil; and a second permanent magnet for connecting said first and second yokes, wherein said single-phase coil is movable, said first and second yokes are fixed yokes each having a straight portion over an entire stroke of said single-phase coil, said first permanent magnet is a magnet fixed to the straight portion of one of said first and second yokes and opposing, with one of its magnetic poles, said single-phase coil over the entire stroke of said single-phase coil, and said second permanent magnet connects said first and second yokes outside the stroke.
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Specification