Indicator Element For A Magnetic Rotation Angle Sensor

• US 20080231262A1
• Filed: 03/14/2008
• Published: 09/25/2008
• Est. Priority Date: 03/22/2007
• Status: Active Grant

• Current Assignee: Tyco Electronics AMP GmbH (TE Connectivity Limited)
• Original Assignee: Tyco Electronics AMP GmbH (TE Connectivity Limited)
• Inventors: Hoffelder, Bernd, Wolf, Marco
• Granted Patent: US 7,830,138 B2
• Time in Patent Office: Days
• US Class Current: 324/207.2
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06

Abstract

An indicator element for a magnetic rotation angle sensor having a field probe for generating a sensor signal in response to a geometric position of the indicator element relative to the field probe is disclosed. The indicator element has a permanent magnet with an annular cross-section having a plurality of segments, magnetization of the segments being in different directions so that a homogeneous magnetic field is formed in an inner region of the indicator element into which the field probe is arranged. At least two segments exhibit radial or diametrical magnetization and at least two segments exhibit lateral magnetization.

Claims

1. An indicator element for a magnetic rotation angle sensor comprising a field probe for generating a sensor signal in response to a geometric position of the indicator element relative to the field probe, the indicator element comprising:

a permanent magnet with an annular cross-section having a plurality of segments, magnetization of the segments being in different directions so that a homogeneous magnetic field is formed in an inner region of the indicator element into which the field probe is arranged;

wherein at least two segments exhibit radial or diametrical magnetization and at least two segments exhibit lateral magnetization.

2. The indicator element according to claim 1, wherein the segments are each formed by different ring segments of the permanent magnet.

3. The indicator element according to claim 1, wherein the segments are assembled in such a way that there are continuous transitions between magnetic field directions of the segments.

4. The indicator element according claim 1, wherein the indicator element is constructed of a plastic-bonded magnetic material.

5. The indicator element according to claim 4, wherein the indicator element is constructed of a plastic-bonded ferrite material and/or a plastic-bonded rare earth material.

6. The indicator element according to claim 4, wherein the indicator element is constructed by injection molding.

7. The indicator element according to claim 5, wherein the indicator element is constructed by injection molding.

8. A magnetic rotation angle sensor with a first field probe for generating a sensor signal in response to a geometric position of an indicator element relative to the first field probe, the indicator element comprising:

a permanent magnet with an annular cross-section having a plurality of segments, magnetization of the segments being in different directions so that a homogeneous magnetic field is formed in an inner region of the indicator element into which the first field probe is arranged;

wherein at least two segments exhibit radial or diametrical magnetization diametrical and at least two segments exhibit lateral magnetization

9. The magnetic rotation angle sensor according to claim 8, wherein the first field probe comprises at least one Hall effect device.

10. The magnetic rotation angle sensor according to claim 8, wherein the first field probe comprises at least one magnetoresistive sensor.

11. The magnetic rotation angle sensor according to claim 10, wherein the at least one magnetoresistive sensor comprises an anisotropic magnetoresistive sensor.

12. The magnetic rotation angle sensor according to claim 10, wherein the at least one magnetoresistive sensor comprises a giant magnetoresistive sensor.

13. The magnetic rotation angle sensor according to claim 10, wherein the at least one magnetoresistive sensor comprises a tunnel magnetoresistive sensor.

14. The magnetic rotation angle sensor according to claim 8, wherein a second field probe is arranged so as to be axially spaced from the first field probe in order to generate a redundant sensor signal.

15. The magnetic rotation angle sensor according to claim 8, wherein a third field probe is arranged so as to be radially spaced from the first field probe in order to generate a redundant sensor signal.

16. The magnetic rotation angle sensor according to claim 8, wherein the indicator element is arranged on a rotor so as to be rotatable relative to the first field probe.

17. The magnetic rotation angle sensor according to claim 8, wherein the first field probe is arranged on a rotor so as to be rotatable relative to the indicator element.