Device for contactless measuring of rotational angle or rotational speed
First Claim
1. A device for contactless measuring at least one of rotational angle and a rotational speed of a shaft which is in one of stationary and rotational conditions, said device comprising a disk body fixedly and coaxially supported on said shaft for joint rotation therewith and having two opposing axial sides, at least one of said two axial opposing sides having a continuously extending concentric region formed of an electrically conductive material and comprising at least one uniformly widening segment, said disc body being formed of material which is different from the electrically conductive material said continuously extending concentric region is formed of;
- at least two sensor coils connected to an AC power source and arranged coaxially relative to each other on said two opposing sides, respectively, in a fixed position with respect to said disk body and operatively associated with said region of an electrically conductive material, each of said two sensor coils having an impedance which varies in accordance with a size of an area of said region of an electrically conductive material each of said two sensor coils are operatively associated with; and
an evaluating circuit for measuring variations of the impedance of said two sensor coils to thereby measure the at least one of the rotational angle and the rotational speed by adding signals form said two sensor coils, all elements of said evaluating circuit being so selected that a substantially linear characteristic line is obtained for determining the at least one of the rotational angle and the rotational speed.
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Accused Products
Abstract
In a measurement device for contactless determination of the rotation angle and/or rotation speed, a disk is fastened on a shaft so as to be fixed with respect to rotation relative to it. During the measurement process, layers of material with good electrical conductivity which are arranged on one or both opposing sides of the disk are moved relative to receiver coils located on opposite sides of the disk (16a and 16b). The measurement device can work according to the eddy current measurement method, as well as according to the inductive method. In order to compensate for measurement errors, the conductive layers are arranged at approximately equal distances (a, b) between two coils. In addition, the greatest possible quantity of measurement points can be used for forming an average.
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Citations
10 Claims
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1. A device for contactless measuring at least one of rotational angle and a rotational speed of a shaft which is in one of stationary and rotational conditions, said device comprising a disk body fixedly and coaxially supported on said shaft for joint rotation therewith and having two opposing axial sides, at least one of said two axial opposing sides having a continuously extending concentric region formed of an electrically conductive material and comprising at least one uniformly widening segment, said disc body being formed of material which is different from the electrically conductive material said continuously extending concentric region is formed of;
- at least two sensor coils connected to an AC power source and arranged coaxially relative to each other on said two opposing sides, respectively, in a fixed position with respect to said disk body and operatively associated with said region of an electrically conductive material, each of said two sensor coils having an impedance which varies in accordance with a size of an area of said region of an electrically conductive material each of said two sensor coils are operatively associated with; and
an evaluating circuit for measuring variations of the impedance of said two sensor coils to thereby measure the at least one of the rotational angle and the rotational speed by adding signals form said two sensor coils, all elements of said evaluating circuit being so selected that a substantially linear characteristic line is obtained for determining the at least one of the rotational angle and the rotational speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- at least two sensor coils connected to an AC power source and arranged coaxially relative to each other on said two opposing sides, respectively, in a fixed position with respect to said disk body and operatively associated with said region of an electrically conductive material, each of said two sensor coils having an impedance which varies in accordance with a size of an area of said region of an electrically conductive material each of said two sensor coils are operatively associated with; and
Specification