MEASURING LINEAR VELOCITY
First Claim
1. An apparatus for measuring linear velocity of a movable element relative to a stationary element along an axis of movement, the apparatus comprising:
- a magnetic element fixed in relation to the stationary element, the magnetic element having a permanent magnet;
a soft-magnetic yoke fixed in relation to the movable element to move with the movable element relative to the stationary element, the soft-magnetic yoke being in non-contact relation with the magnetic element and having a pole positioned proximate to the magnetic element and spaced from the magnetic element by an air gap, the pole magnetically coupled to the magnetic element so that a magnetic flux is generated in the air gap substantially orthogonal to the axis of movement; and
a conductive coil coiled around a coil axis, the conductive coil fixed in relation to the stationary element with the coil axis substantially parallel to the axis of movement, in non-contact relation with the soft-magnetic yoke and residing between the magnetic element and the pole of the soft-magnetic yoke in the magnetic flux.
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Accused Products
Abstract
An apparatus for measuring linear velocity of a movable element relative to a stationary element includes a magnetic element fixed in relation to the stationary element. A soft-magnetic yoke is fixed in relation to the movable element to move with the movable element and is in non-contact relation with the magnetic element. A yoke pole is positioned proximate to the magnetic element and spaced therefrom by an air gap. The pole is magnetically coupled to the magnetic element so that a magnetic flux is generated in the air gap substantially orthogonal to the axis of motion. A conductive coil is coiled around a coil axis and is fixed in relation to the stationary element with the coil axis substantially parallel to the axis of movement. The coil is in non-contact relation with the yoke and resides between the magnetic element and the pole of the yoke in the magnetic flux.
89 Citations
19 Claims
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1. An apparatus for measuring linear velocity of a movable element relative to a stationary element along an axis of movement, the apparatus comprising:
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a magnetic element fixed in relation to the stationary element, the magnetic element having a permanent magnet; a soft-magnetic yoke fixed in relation to the movable element to move with the movable element relative to the stationary element, the soft-magnetic yoke being in non-contact relation with the magnetic element and having a pole positioned proximate to the magnetic element and spaced from the magnetic element by an air gap, the pole magnetically coupled to the magnetic element so that a magnetic flux is generated in the air gap substantially orthogonal to the axis of movement; and a conductive coil coiled around a coil axis, the conductive coil fixed in relation to the stationary element with the coil axis substantially parallel to the axis of movement, in non-contact relation with the soft-magnetic yoke and residing between the magnetic element and the pole of the soft-magnetic yoke in the magnetic flux. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method comprising:
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communicating magnetic flux between a magnet fixed in relation to a stationary element and a soft-magnetic structure fixed in relation to a movable element; and generating a voltage proportional to a linear velocity of the movable element in relation to the stationary element on a conductive coil fixed in relation to the magnet and residing between the magnet and the structure. - View Dependent Claims (12, 13, 14)
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15. An electric machine system, the system comprising:
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a first assembly that moves in relation to a second assembly along an axis of movement, a magnet fixed in relation to the second assembly; a coil wound around an axis, the coil fixed in relation to the second assembly with the axis substantially parallel to the axis of movement; a soft-magnetic structure fixed in relation to the first assembly to move with the first assembly in relation to the second assembly; the magnet and the soft-magnetic structure cooperating to define a magnetic circuit conducting magnetic flux from the magnet through the coil substantially perpendicular to the coil axis and into the soft-magnetic structure; and an electronics module in electrical communication with the electrical coil and fixed in relation to the second assembly. - View Dependent Claims (16, 17, 18, 19)
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Specification