Hall effect monitoring of wear of bearing supporting a rotor within a stationary housing

An apparatus for monitoring a rotor within a stationary housing, said stationary housing including bearing means for mounting said rotor for rotation about a rotor axis, said apparatus comprising:

• at least one magnet mounted about the circumference of said rotor;
• first radial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor for sensing magnetic flux density through said containment shell as said at least one magnet passes thereby and for generating a first distance signal representative of the distance separating said first radial hall effect means and said rotor in response to said magnetic flux density;
• second radial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor for sensing magnetic flux density through said containment shell as said at least one magnet passes thereby and for generating a second distance signal representative of the distance separating said second radial hall effect means and said rotor in response to said magnetic flux density;
• third radial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor for sensing magnetic flux density through said containment shell as said at least one magnet passes thereby and for generating a third distance signal representative of the distance separating said third radial hall effect means and said rotor in response to said magnetic flux density;
• fourth radial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor for sensing magnetic flux density through said containment shell as said at least one magnet passes thereby and for generating a fourth distance signal representative of the distance separating said fourth radial hall effect means and said rotor in response to said magnetic flux density;
• first axial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor and spaced a defined distance on one side of said plane for generating a first axial signal as said at least one magnet passes thereby;
• second axial hall effect means fixedly mounted in said housing radially adjacent to the circumference of said rotor and spaced a defined distance on a side opposite to said one side of said plane for generating a second axial signal as said at least one magnet passes thereby;
• and,
• signal comparison means for comparing said first and second distance signals to one another to generate a first comparison signal which is representative of the difference between the distance separating said first radial hall effect means and said rotor and the distance separating said second radial hall effect means and said rotor, said first comparison signal being representative of radial wear of said bearing means along a first axis which passes through said first and second radial hall effect means, for comparing said third and fourth distance signals to one another to generate a second comparison signal which is representative of the difference between the distance separating said third radial hall effect means and said rotor and the distance separating said fourth radial hall effect means and said rotor, said second comparison signal being representative of radial wear of said bearing means along a second axis which passes through said third and fourth radial hall effect means, and for comparing said first and second axial signals to one another to generate an axial wear signal which is indicative of axial wear for said bearing means.

An apparatus for monitoring a rotor within a stationary housing including bearing means for mounting said rotor for rotation about a rotor axis, said apparatus comprising;

• first, second, third and fourth magnets fixedly mounted within said housing;
• magnetic material means mounted on the circumference of said rotor for acting with said first, second, third and fourth magnets to conduct magnetic flux which passes between said rotor and said housing;
• first radial hall effect means fixedly mounted in said housing adjacent to said first magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a first distance signal representative of the distance separating said first radial hall effect means and said rotor in response to said magnetic flux density;
• second radial hall effect means fixedly mounted in said housing adjacent to said second magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a second distance signal representative of the distance separating said second radial hall effect means and said rotor in response to said magnetic flux density;
• third radial hall effect means fixedly mounted in said housing adjacent to said third magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a third distance signal representative of the distance separating said third radial hall effect means and said rotor in response to said magnetic flux density;
• fourth radial hall effect means fixedly mounted in said housing adjacent to said fourth magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a fourth distance signal representative of the distance separating said fourth radial hall effect means and said rotor in response to said magnetic flux density, said first, second, third and fourth radial hall effect means being spaced substantially equidistantly about a circumferential portion of said housing;
• and
• signal comparison means for comparing said first and second distance signals to one another to generate a first comparison signal which is representative of the difference between the distance separating said first radial hall effect means and said rotor and the distance separating said second radial hall effect means and said rotor, for comparing said third and fourth distance signals to one another to generate a second comparison signal which is representative of the difference between the distance separating said third radial hall effect means and said rotor and the distance separating said fourth radial hall effect means and said rotor, said first comparison signal being representative of radial wear of said bearing means along a first axis which passes through said first and second radial hall effect means and said second comparison signal being representative of radial wear of said bearing means along a second axis which passes through said third and fourth radial hall effect means, said first and second axes being substantially perpendicular to one another and defining a plane which is substantially perpendicular to said rotor axis, said signal comparison means further generating a resultant wear signal indicative of resultant radial wear of said bearing means by taking the square root of the sum of the squares of said first and second comparison signals.

An apparatus for monitoring a rotor within a stationary housing, said stationary housing including bearing means for mounting said rotor for rotation about a rotor axis said apparatus comprising:

• first, second, third and fourth magnets fixedly mounted within said housing;
• magnetic material means mounted on the circumference of said rotor for acting with said first, second third and fourth magnets to conduct magnetic flux which passes between said rotor and said housing;
• first radial hall effect means fixedly mounted in said housing adjacent to said first magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a first radial hall effect means of the distance separating said first radial hall effect means and said rotor in response to said magnetic flux density;
• second radial hall effect means fixedly mounted in said housing adjacent to said second magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a second distance signal representative of the distance separating said second radial hall effect means and said rotor in response to said magnetic flux density;
• third radial hall effect means fixedly mounted in said housing adjacent to said third magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a third distance signal representative of the distance separating said third radial hall effect means and said rotor in response to said magnetic flux density;
• fourth radial hall effect means fixedly mounted in said housing adjacent to said fourth magnet and radially adjacent to the circumference of said rotor for sensing magnetic flux density when said magnetic material means is positioned radially adjacent thereto and for generating a fourth distance signal representative of the distance separating said fourth radial hall effect means and said rotor in response to said magnetic flux density;
• first axial hall effect means fixedly mounted in said housing adjacent to said first magnet, radially adjacent to the circumference of said rotor and spaced a defined distance on one side of said plane for sensing magnetic flux density when said magnetic material means is positioned adjacent thereto and for generating a first axial signal in response to sensing said magnetic flux density;
• second axial hall effect means fixedly mounted in said housing adjacent to said second magnet, radially adjacent to the circumference of said rotor and spaced a defined distance on a side opposite to said one side of said plane for sensing magnetic flux density when said magnetic material means is positioned adjacent thereto and for generating a second axial signal in response to sensing said magnetic flux density;
• and,
• signal comparison means for comparing said first and second distance signals to one another to generate a first comparison signal which is representative of the difference between the distance separating said first radial hall effect means and said rotor and the distance separating said second radial hall effect means and said rotor, said first comparison signal being representative of radial wear of said bearing means along a first axis which passes through said first and second radial hall effect means, for comparing said third and fourth distance signals to one another to generate a second comparison signal which is representative of the difference between the distance separating said third radial hall effect means and said rotor and the distance separating said fourth radial hall effect means and said rotor, said second comparison signal being representative of radial wear of said bearing means along a second axis which passes through said third and fourth radial hall effect means, and for comparing said first and second axial signals to one another to generate an axial wear signal which is indicative of axial wear for said bearing means.