Magnetic circuit for a rotary position sensor
First Claim
1. An angular position sensor comprising:
- a rotatable magnet disposed for rotation about a first axis and generating a variable magnetic field in response to rotation about the first axis;
a magnetically sensitive device disposed remotely from the rotatable magnet along a second axis, the second axis being perpendicular to the first axis;
the magnetically sensitive device being sensitive to magnitude and direction of the variable magnetic field, and the magnetically sensitive device adapted to generate an output signal indicative of the magnitude and direction of the variable magnetic field;
a first pole piece having a first segment, a second segment, and a third segment; and
a second pole piece having a fourth segment, a fifth segment, and a sixth segment;
wherein the first segment and the fourth segment are disposed about the second axis at a first distance such that the first segment and the fourth segment are mutually parallel to the second axis; and
further wherein the third segment and the sixth segment are disposed about the second axis at a second distance such that the third segment and the sixth segment are mutually parallel to the second axis, the second distance being less than the first distance; and
further wherein the second segment and the fifth segment are disposed about the second axis such that the second segment and the fifth segment are at an angle to the second axis, the angle being greater than zero and less than ninety degrees.
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Accused Products
Abstract
An angular position sensor is provided including a rotatable magnet and at least one magnetically sensitive device. The at least one magnetically sensitive device is preferably a plurality of Hall effect sensors disposed on a circuit board for processing the generated electrical signals. The present invention includes a pair of focusing members designed to transmit and uniformly focus a magnetic field across the magnetically sensitive device, wherein the focusing members are tailored to be substantially planar and provide a uniform magnetic field gradient across the magnetically sensitive device. In a preferred embodiment, the present invention also includes at least one shielding member. The angular position sensor may be adapted for use in a control system for the electronic monitoring and control of the throttle plate position in a motor vehicle.
39 Citations
20 Claims
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1. An angular position sensor comprising:
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a rotatable magnet disposed for rotation about a first axis and generating a variable magnetic field in response to rotation about the first axis;
a magnetically sensitive device disposed remotely from the rotatable magnet along a second axis, the second axis being perpendicular to the first axis;
the magnetically sensitive device being sensitive to magnitude and direction of the variable magnetic field, and the magnetically sensitive device adapted to generate an output signal indicative of the magnitude and direction of the variable magnetic field;
a first pole piece having a first segment, a second segment, and a third segment; and
a second pole piece having a fourth segment, a fifth segment, and a sixth segment;
wherein the first segment and the fourth segment are disposed about the second axis at a first distance such that the first segment and the fourth segment are mutually parallel to the second axis; and
further wherein the third segment and the sixth segment are disposed about the second axis at a second distance such that the third segment and the sixth segment are mutually parallel to the second axis, the second distance being less than the first distance; and
further wherein the second segment and the fifth segment are disposed about the second axis such that the second segment and the fifth segment are at an angle to the second axis, the angle being greater than zero and less than ninety degrees.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A throttle plate position control system comprising:
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a throttle plate coupled to a rotatable shaft, the rotatable shaft including a rotatable magnet, the rotatable magnet disposed for rotation about a first axis and generating a variable magnetic field in response to rotation about the first axis;
a first pole piece and a second pole piece disposed about a second axis such that the first pole piece has a first end segment and the second pole piece has a second end segment, the first and second end segments transmit and focus the variable magnetic field across a gap therebetween;
a magnetically sensitive device disposed at the gap;
the magnetically sensitive device being sensitive to magnitude and direction of the variable magnetic field, and the magnetically sensitive device adapted to generate an output signal indicative of the magnitude and direction of the variable magnetic field; and
wherein the first and second end segments have a surface area larger than the magnetically sensitive device thereby expanding the magnetic field and producing an increase in uniformity of the magnetic field. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A throttle plate position control system comprising:
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a throttle plate coupled to a rotatable shaft, the rotatable shaft including a rotatable magnet, the rotatable magnet disposed for rotation about a first axis and generating a variable magnetic field in response to rotation about the first axis;
a first pole piece and a second pole piece disposed about a second axis such that the first pole piece has a first end segment and the second pole piece has a second end segment, the first and second end segments transmit and focus the variable magnetic field across a gap therebetween;
a magnetically sensitive device disposed at the gap;
the magnetically sensitive device being sensitive to magnitude and direction of the variable magnetic field, and the magnetically sensitive device adapted to generate an output signal indicative of the magnitude and direction of the variable magnetic field;
wherein the first and second end segments have a surface area larger than the magnetically sensitive device thereby expanding the magnetic field and producing an increase in uniformity of the magnetic field;
wherein the first segment and the fourth segment are disposed about the second axis at a first distance such that the first segment and the fourth segment are mutually parallel to the second axis; and
further wherein the third segment and the sixth segment are disposed about the second axis at a second distance such that the third segment and the sixth segment are mutually parallel to the second axis, the second distance being less than the first distance; and
further wherein the second segment and the fifth segment are disposed about the second axis such that the second segment and the fifth segment are at an angle to the second axis, the angle being greater than zero and less than ninety degrees.
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Specification