Angle measurement system including magnet with substantially square face for through-shaft applications
AssigneeInfineon Technologies AG
InventorJames William Sterling
Life of this patent
Estimating the term…
Abstract
To make the magnetic field lines straighter and more parallel to one another, the present disclosure makes use of substantially square magnets with through-holes therein. It will be appreciated that “substantially square” magnets include magnets that are precisely square as well as magnets that are approximately square (e.g., have rounded corners or other small deviations from being square.) By providing straighter and more parallel magnetic field lines, such substantially square magnets tend to enable greater precision and accuracy when rotational angles of a shaft are measured.
Claims18
An angle measurement system, comprising:
- a shaft extending along a shaft axis and configured to axially rotate thereabout;
- a magnet including first and second surfaces, wherein the first and second surfaces include first and second apertures, respectively, and wherein the first and second apertures define extents of a through-hole in the magnet through which the shaft extends so opposing ends of the shaft extend entirely through the magnet and past the first and second surfaces, and
- an angle sensor configured to measure a time-varying magnetic field produced by the magnet as the shaft rotates, wherein the angle sensor includes a sensing region that is positioned over the first surface of the magnet and is radially spaced apart from a sidewall of the shaft;
- where the shaft is adapted to rotate through an absolute angle of more than three-hundred and sixty degrees about the shaft axis.
A system, comprising:
- a shaft that extends along a shaft axis;
- a magnet having first and second surfaces that are substantially square with rounded corners, wherein the magnet includes an aperture through which the shaft passes so opposing ends of the shaft extend entirely through the magnet and past the first and second surfaces;
- and
- an angle sensor to determine a rotational angle of the shaft by measuring a time-varying magnetic field produced by the magnet as the shaft rotates, wherein the angle sensor includes a sensing region that is positioned over the first or second surface of the magnet and is radially spaced apart from a sidewall of the shaft;
- where the shaft is adapted to rotate through an absolute angle of more than three-hundred and sixty degrees about the shaft axis.
Dependencies are inferred from the claim text.