Rotation angle sensor, in particular steering angle sensor for a steering unit
The invention concerns a rotation angle sensor, in particular a steering angle sensor ( 1 ) for a steering unit, with a housing ( 2 ) comprising an exterior ( 8 ), a pick-up sensor ( 7 ) arranged in a sensor chamber in the housing ( 2 ) to perform rotary movements around a rotation axis, and a stationary receiver interacting with the pick-up sensor ( 7 ). It is endeavored to make such steering angle sensors fit for rough environmental conditions. For this purpose, the sensor chamber is connected to the exterior ( 8 ) via at least one free space ( 16 ).
1. A rotation angle sensor comprising:
a housing having an exterior and a sensor chamber,
a pick-up sensor arranged in the sensor chamber, wherein the pick-up sensor is configured to perform rotary movements around a rotation axis, and
a stationary receiver for interacting with the pick-up sensor,
wherein the sensor chamber is connected to the exterior via at least one free space, and
wherein the pick-up sensor is arranged on a retaining ring that rests on an axial bearing surface on the exterior of the housing.
2. The rotation angle sensor according to claim 1 , wherein the at least one free space is a channel extending transversely to the rotation axis.
3. The rotation angle sensor according to claim 1 , wherein the at least one free space has a cross-section with an extension tangentially to the pick-up sensor amounting to at least 25% of the largest diameter of the pick-up sensor.
4. The rotation angle sensor according to claim 1 , wherein the at least one free space has a cross-section with an extension in parallel to the rotation axis amounting to at least 25% of an extension laterally to the rotation axis.
5. The rotation angle sensor according to claim 1 , wherein the stationary receiver is arranged in a hermetically enclosed unit, which is detachably connected to the housing.
6. The rotation angle sensor according to claim 5 , wherein the hermetically sealed unit is connected to the housing by means of a snap connection.
7. The rotation angle sensor according to claim 6 , wherein the snap connection has at least one snap hook, and
wherein the snap connection may be accessed from a side of the hermetically sealed unit facing away from the housing.
8. The rotation angle sensor according to claim 5 , wherein the hermetically sealed unit projects at least partly into the sensor chamber.
9. The rotation angle sensor according to claim 1 , wherein the housing has a projection surrounding the axial bearing surface.
10. The rotation angle sensor according to claim 9 , wherein the projection has a length in an axial direction equal to a length of a part of the retaining ring resting on the exterior of the axial bearing surface.
11. The rotation angle sensor according to claim 1 , wherein the retaining ring has an opening for accommodating a steering handwheel shaft, and
wherein the retaining ring has at least one spring finger projecting into said opening.
12. The rotation angle sensor according to claim 1 , wherein the pick-up sensor is a magnetic pick-up sensor.
13. The rotation angle sensor according to claim 1 , wherein a purification device is arranged in the sensor chamber, and
wherein the purification device can be activated by the pick-up sensor.