Position detection device for magnetic bearing
First Claim
1. A position detection device for detecting the position of a movable member in relation to a fixed member along two axes, said position detection device comprising:
- a capacitive transducer including a fixed member and a movable member separted from each other by an annular gap;
said fixed member comprising first and second axially separted equal-diameter metallic electrode rings, the first of said rings being a continuous metallic electrode mounted onto an insulating support and the second of said rings comprising four thin metal foil electrodes separated by four equal-width narrow gaps spaced at angular intervals of 90°
mounted onto an insulating support;
said movable member comprising a thin walled metallic cylinder concentrically surrounding the fixed member such that said movable member capacitively coupled the first and second electrode rings of said fixed member;
means for connecting each pair of diametrically opposed electrodes of said second ring of the fixed member to an electronic position control circuit; and
means for connecting the first ring of the fixed member to a voltage source.
1 Assignment
0 Petitions
Accused Products
Abstract
A device comprising a capacitive transducer comprised of a fixed member comprising first and second axially separated equal diameter metallic electrode rings and a movable member comprised of a thin walled metallic cylinder separated from the fixed member by an annular gap such that said movable member capacitively couples said first and second rings of the fixed member. The first ring of the fixed member is comprised of a continuous metallic ring glued onto an insulating supporting means, and the second ring is comprised of four thin metal foil electrodes separated by four equi-width narrow gaps spaced at angular intervals of 90° and glued onto an insulating supporting means. The first electrode ring of the fixed member is electrically connected to an alternating current power source and each pair of diametrically opposed electrodes of the second ring of the fixed member are electrically connected to a position control loop circuit.
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Citations
6 Claims
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1. A position detection device for detecting the position of a movable member in relation to a fixed member along two axes, said position detection device comprising:
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a capacitive transducer including a fixed member and a movable member separted from each other by an annular gap; said fixed member comprising first and second axially separted equal-diameter metallic electrode rings, the first of said rings being a continuous metallic electrode mounted onto an insulating support and the second of said rings comprising four thin metal foil electrodes separated by four equal-width narrow gaps spaced at angular intervals of 90°
mounted onto an insulating support;said movable member comprising a thin walled metallic cylinder concentrically surrounding the fixed member such that said movable member capacitively coupled the first and second electrode rings of said fixed member; means for connecting each pair of diametrically opposed electrodes of said second ring of the fixed member to an electronic position control circuit; and means for connecting the first ring of the fixed member to a voltage source. - View Dependent Claims (2, 3, 4)
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5. In a magnetic suspension apparatus comprising a stator member, a rotor member coaxial with the stator member, the rotor member surrounding the stator member with a radial annular gap therebetween, and further comprising permanent magnet means on the stator or rotor member, said stator member including electromagnetic coils for generating, when traversed by an electric current, magnetic fluxes across said radial annular gap for the control of the radial position of the rotor member relative to the stator member, the improvement comprising:
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a position detection device for detecting the radial position of the rotor member in relation to the stator member, said position detection device comprising a capacitive transducer including a fixed member and a movable member separated from each other by a radial annular gap, the fixed member being attached to said stator member and the movable member being attached to said rotor member, and an electrostatic screen made of a nonmagnetic electro-conductive material, said electrostatic screen being attached to the stator member so as to be positioned between the fixed member of the transducer and said electromagnetic coils. - View Dependent Claims (6)
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Specification