Sensor device for determining a displacement of a shaft
The present disclosure relates to sensor devices and the teachings may be applied to a sensor for determining a displacement of a shaft along its longitudinal axis. In some embodiments, a sensor device may include a sensor unit and a detection element. The sensor element is disposed at a fixed radial distance from the longitudinal axis. The detection element is arranged between the shaft and the sensor unit and coupled to the shaft. The side of the detection element facing away from the axis comprises a convex shape. A gap distance defined between the detection element and the sensor unit varies over an extent of the sensor unit perpendicularly with respect to the longitudinal axis and independently of a tilting angle of the shaft. The sensor unit generates a shaft displacement signal dependent on a displacement of the detection element in relation to the sensor unit along the longitudinal axis.
1. A sensor device for determining a displacement of a shaft along its longitudinal axis, the sensor device comprising:
a sensor unit disposed at a first radial distance from the longitudinal axis, wherein the shaft moves in relation to the sensor unit along the longitudinal axis;
a detection element arranged between the shaft and the sensor unit and fixedly coupled to the shaft at a second radial distance from the longitudinal axis;
wherein a first side of the detection element facing away from the longitudinal axis comprises a convex shape with respect to a plane perpendicular to the longitudinal axis and a gap distance defined between the detection element and the sensor unit varies over an extent of the sensor unit perpendicularly with respect to the longitudinal axis and independently of a tilting angle of the shaft;
wherein the sensor unit generates a shaft displacement signal dependent on a displacement of the detection element in relation to the sensor unit along the longitudinal axis.
2. The sensor device as claimed in claim 1 , wherein a curvature of the first side of the detection element comprises a substantially circular curve in the plane perpendicular to the longitudinal axis, the circular curve having a radius corresponding to the second radial distance.
3. The sensor device as claimed in claim 1 , wherein the detection element comprises a lamellar.
4. The sensor device as claimed in claim 1 , wherein the detection element comprises a conductor loop.
5. The sensor device as claimed in claim 1 , wherein:
the sensor unit comprises an exciter coil and at least one receiver coil; and
the exciter coil generates a magnetic field inducing a respective voltage in the at least one receiver coil, wherein a strength of the induced voltage depends on the displacement of the detection element with respect to the sensor unit.
6. The sensor device as claimed in claim 1 , wherein:
the detection element comprises a permanent magnet; and
the sensor unit comprises a Hall sensor penetrated, as a function of the displacement of the permanent magnet with respect to the sensor unit, by a magnetic field which is brought about by the permanent magnet.
7. The sensor device claimed in claim 1 , wherein: the detection element comprises a permanent magnet; and the sensor unit comprises a magneto-resistive sensor element which is penetrated, as a function of the displacement of the permanent magnet with respect to the sensor unit, by a magnetic field which is brought about by the permanent magnet.
8. The sensor device as claimed in claim 1 , wherein:
the detection element comprises at least a first electrode of a capacitor; and
the sensor unit comprises at least a second electrode of the capacitor.
9. An exhaust gas recirculation valve arranged in the exhaust gas train of an internal combustion engine in order to control an exhaust gas flow, the recirculation valve comprising:
an inlet;
an outlet;
a valve seat with a valve disk coupled to a shaft comprises a valve rod;
wherein the position of the valve disk with respect to the valve seat can be adjusted by means of a displacement of the shaft along a longitudinal axis of the shaft;
wherein the exhaust gas recirculation valve controls the exhaust gas flow from the inlet to the outlet as a function of the position of the valve disk with respect to the valve seat;
a sensor unit disposed at a first radial distance from the longitudinal axis, wherein the shaft moves in relation to the sensor unit along the longitudinal axis;
a detection element arranged between the shaft and the sensor unit and fixedly coupled to the shaft at a second radial distance from the longitudinal axis;
wherein a first side of the detection element facing away from the longitudinal axis comprises a convex shape with respect to a plane perpendicular to the longitudinal axis and a gap distance defined between the detection element and the sensor unit varies over an extent of the sensor unit perpendicularly with respect to the longitudinal axis and independently of a tilting angle of the shaft;
wherein the sensor unit generates a shaft displacement signal dependent on a displacement of the detection element in relation to the sensor unit along the longitudinal axis.