Magnetic angle sensor unit having ferromagnetic conductive shielding
AssigneeASM Automation Sensorik Messtechnik GmbH
InventorsKlaus Manfred Steinich, Peter Wirth
Life of this patent
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Abstract
A sensor unit including a Hall or magnetoresistive angle sensor detecting around its longitudinal axis. The angle sensor includes a magnetically sensitive face surface portion and sensor element proximal to a face surface fixed in place. At least one magnet unit is disposed so that its magnetic field permeates the angle sensor, and field lines of at least one encoder magnetic of the at least one magnetic unit extend parallel to a sensitive plane of the sensor element wherein the encoder magnet is rotatable. A magnetically conductive shielding made of ferromagnetic material includes at least one sensor shielding fixed in place and an encoder shielding rotatable together with the encoder magnet.
Claims11
A sensor unit (100), said sensor comprising:
- an Hall or magnetoresistive angle sensor (1) detecting around its longitudinal axis (10a), includes a magnetically sensitive face surface portion and a sensor element (4) proximal to a face surface (2a) which is fixed in place;
- and
- at least one magnet unit (50) disposed so that its magnetic field permeates the angle sensor (1), and field lines of at least one encoder magnet (50a) of the at least one magnet unit (50) extend parallel to a sensitive plane (4′) of the sensor element (4) wherein the encoder magnet is rotatable;
- and
- a magnetically conductive shielding (101) made of ferromagnetic material including at least one sensor shielding fixed in place and an encoder shielding rotatable together with the encoder magnet (50) wherein said sensor shielding (101a) is disposed closer than 6 mm to said sensor element (4), and the material of said sensor shielding (101a) has a coercitive field strength HC<5 A/cm.
A sensor unit (100), said sensor comprising:
- an Hall or magnetoresistive angle sensor (1) detecting around its longitudinal axis (10a), including a magnetically sensitive face surface portion and a sensor element (4) proximal to a face surface (2a) which is fixed in place;
- at least one magnet unit (50 disposed so that its magnetic field permeates the angle sensor (1), and field lines of at least one encoder magnet (50a) of the at least one magnet unit (50) extend parallel to a sensitive plane (4′) of the sensor element (4) wherein the encoder magnet is rotatable;
- a magnetically conductive shielding (101) made of ferromagnetic material including at least one sensor shielding fixed in place and an encoder shielding rotatable together with the encoder magnet (50);
- and
- an intermediary unit (70) between said angle sensor and said at least one magnet unit in which at least one intermediary magnet (71) is disposed with its pole axis (72) extending parallel to a sensitive plane (4) of said sensor element (4) rotatable around a longitudinal axis (10a) in the intermediary unit (70) by means of ferrofluid (73) wherein two encoder magnets (50a, b) impact the intermediary magnet (71) and rotate with it.
Dependencies are inferred from the claim text.