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US 6,275,027 B1Granted
Rotation angle sensor
AssigneeUnisia Jecs Corporation
InventorsYoshihiro Kogure, Hirotsugu Nakazawa
Life of this patent
Estimating the term…
Abstract
A rotation angle sensor including a magnet rotatable about an axis, a first and second yokes arranged around said magnet and diametrically opposed to each other, and a Hall effect device disposed between the first and second yokes. The yokes include arcuately curved pole piece portions radially opposed to the magnet and overhang portions extending angularly inwardly from the pole piece portions across the axis of the magnet, respectively. The overhang portions have a generally sector shape and cooperate to define a gap therebetween within which the Hall effect device is disposed. Leakage flux reducing members circumferentially extend between the pole piece portions.
Claims17
A rotation angle sensor comprising:
- a magnet, said magnet having an axis about which said magnet is rotatable;
- a first yoke arranged around said magnet, said first yoke including a first pole piece portion radially opposed to said magnet and a first overhang portion extending radially inwardly from said first pole piece portion across said axis of said magnet;
- a second yoke arranged around said magnet, said second yoke cooperating with said magnet and said first yoke to form a magnetic circuit, said second yoke including a second pole piece portion radially opposed to said magnet and diametrically opposed to said first pole piece portion and a second overhang portion extending radially inwardly from said second pole piece portion across said axis of said magnet, said second overhang portion being opposed to said first overhang portion in a direction of said axis of said magnet;
- and
- a signal generating device operative, in response to rotation of said magnet relative to said first and second yokes, to detect a density of magnetic flux generated by said magnet and passing through said first and second yokes and generate an output signal indicative of the density of magnetic flux detected, said signal generating device being disposed between said first and second overhang portions;
- a flexible substrate to which said signal generating device is mounted, and
- a casing enclosing said magnet, said first and second yokes, said signal generating device and said flexible substrate, said flexible substrate being arranged in a bent state within said casing.
4 more elements
A rotation angle sensor comprising:
- a magnet, said magnet having an axis about which said magnet is rotatable;
- a first yoke arranged around said magnet, said first yoke including a first pole piece portion radially opposed to said magnet and a first overhang portion extending radially inwardly from said first pole piece portion across said axis of said magnet;
- a second yoke arranged around said magnet, said second yoke cooperating with said magnet and said first yoke to form a magnetic circuit, said second yoke including a second pole piece portion radially opposed to said magnet and diametrically opposed to said first pole piece portion and a second overhang portion extending radially inwardly from said second pole piece portion across said axis of said magnet, said second overhang portion being opposed to said first overhang portion in a direction of said axis of said magnet;
- and
- a signal generating device operative, in response to rotation of said magnet relative to said first and second yokes, to detect a density of magnetic flux generated by said magnet and passing through said first and second yokes and generate an output signal indicative of the density of magnetic flux detected, said signal generating device being disposed between said first and second overhang portions;
- and
- wherein said first and second yokes are made of a magnetic material having a coercive force not more than one oersted and said magnet is made of a permanent magnet material having a maximum energy product not more than 20×106 gauss oersted.
4 more elements
A rotation angle sensor, comprising:
- a magnet, said magnet having an axis about which said magnet is rotatable and which passes through said magnet at a point essentially equidistant from opposed ends of the magnet;
- a first yoke arranged around said magnet, said first yoke including a first pole piece portion radially opposed to said magnet and a first overhang portion extending radially inwardly from said first pole piece portion across said axis of said magnet;
- a second yoke arranged around said magnet, said second yoke including a second pole piece portion radially opposed to said magnet and diametrically opposed to said first pole piece portion and a second overhang portion extending radially inwardly from said second pole piece portion across said axis of said magnet, said second overhang portion being opposed to said first overhang portion in a direction of said axis of said magnet;
- a signal generating device operative, in response to rotation of said magnet relative to said first and second yokes, to detect a density of magnetic flux generated by said magnet and passing through said first and second yokes and generate an output signal indicative of the density of magnetic flux detected, said signal generating device being disposed between said first and second overhang portions;
- and
- leakage flux reducing members configured to reduce a circumferential leakage flux between said first and second pole piece portions.
3 more elements
Dependencies are inferred from the claim text.