Low profile non-contacting position sensor
First Claim
1. A rotary position sensor engagable with a rectangular shaft, comprising:
- a) a magnetically permeable pole assembly having a bore therethrough for allowing the shaft to removably extend through the pole assembly, the pole assembly having a shaft retainer attached in the bore, the shaft slideable into the shaft retainer in order to rotate the pole assembly, the pole assembly including;
a1) a first and second disc spaced apart by a backstrap, the backstrap disposed between the first and second discs for magnetically coupling the first and second discs, the bore extending through the first and second discs, an air gap formed between the first and second discs;
b) a pair of magnets attached to the first and second discs along either side of the air gap and being magnetically coupled to provide a closed magnetic path between the pole assembly and the magnets, the magnets having a varying thickness about a circumference, the magnets providing a variable magnetic field about the circumference; and
c) a magnetic field sensor positioned in the air gap and operable to provide an output signal representative of the variable magnetic field as the pole assembly is rotated, the output signal changing magnitude in relation to the relative position of the magnet with respect to the magnetic field sensor.
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Accused Products
Abstract
A low profile non-contacting position sensor for rotational engagement with a shaft. A pole piece has a first and a second piece. A backstrap retains the first and second pieces in parallel and opposing relationship. A shaft passes through at least one of the pieces. The pole piece is held to the shaft by a shaft retainer. A first and second magnet is disposed on the first and second pieces, respectively. A magnetic sensor is positioned between the first and second magnets. A magnetic field sensor such as a hall effect sensor is positioned in an gap and operates to provide an output signal representative of the field strength of the magnet as the shaft rotates. The output signal changes magnitude in relation to the relative position of the magnet with respect to the magnetic field sensor.
55 Citations
2 Claims
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1. A rotary position sensor engagable with a rectangular shaft, comprising:
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a) a magnetically permeable pole assembly having a bore therethrough for allowing the shaft to removably extend through the pole assembly, the pole assembly having a shaft retainer attached in the bore, the shaft slideable into the shaft retainer in order to rotate the pole assembly, the pole assembly including;
a1) a first and second disc spaced apart by a backstrap, the backstrap disposed between the first and second discs for magnetically coupling the first and second discs, the bore extending through the first and second discs, an air gap formed between the first and second discs;
b) a pair of magnets attached to the first and second discs along either side of the air gap and being magnetically coupled to provide a closed magnetic path between the pole assembly and the magnets, the magnets having a varying thickness about a circumference, the magnets providing a variable magnetic field about the circumference; and
c) a magnetic field sensor positioned in the air gap and operable to provide an output signal representative of the variable magnetic field as the pole assembly is rotated, the output signal changing magnitude in relation to the relative position of the magnet with respect to the magnetic field sensor. - View Dependent Claims (2)
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Specification
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- Resources
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Current AssigneeCTS Corporation
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Original AssigneeCTS Corporation
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InventorsFromer, Eric E.
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Primary Examiner(s)Oda, Christine
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Assistant Examiner(s)JOLLY, ANTHONY S
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Application NumberUS09/081,745Time in Patent Office1,002 DaysField of Search324/207.2, 324/207.25, 324/208, 324/251, 324/207, 324/174, 324/173, 324/207.22, 340/671, 340/672, 735/143.9US Class Current324/207.2CPC Class CodesG01B 7/30 for measuring angles or tap...G01D 5/145 influenced by the relative ...
