Slip ring assembly with integral position encoder
A plurality of contact rings are supported in spaced relation on a cylindrical body about a common axis. A housing is located adjacent the contact rings and is configured to permit relative rotation between the contact rings and the housing about the common axis. A plurality of contact brushes each have a proximal end connected to a printed circuit board (PCB). A distal end of each of the contact brushes is slidably engaged with a corresponding one of the contact rings. Optionally a signal generating portion of a position encoder may be mounted on the PCB. The position encoder has a reference portion that is mounted on the cylindrical body.
1. A slip ring assembly, comprising:
a plurality of contact rings;
means for supporting the contact rings in spaced relation about a common axis;
a housing located adjacent the contact rings and configured to permit relative rotation between the contact rings and the housing about the common axis;
means mounted to the housing for supporting a circuit;
a plurality of contact brushes each having a proximal end connected to the circuit supporting means and a distal end slidably engaged with a corresponding one of the contact rings; and
a position encoder having a signal generating portion mounted on the circuit supporting means and a reference portion mounted on the contact ring supporting means.
2. The slip ring assembly of claim 1 wherein the housing includes a pair of shells that enclose the contact rings and reference portion of the position encoder.
3. The slip ring assembly of claim 1 wherein the circuit supporting means includes at least one printed circuit board.
4. The slip ring assembly of claim 1 wherein the contact brushes apply a spring force to their corresponding contact rings.
5. The slip ring assembly of claim 1 wherein the signal generating portion of the position encoder is a Hall effect sensor mounted on the circuit supporting means and the reference portion of the position encoder is a magnetic ring with a plurality of separate circumferentially spaced magnetic domain regions.
6. The slip ring assembly of claim 1 wherein a portion of an electrical connector is mounted on the circuit supporting means.
7. The slip ring assembly of claim 1 wherein the contact ring supporting means includes a generally cylindrical body.
8. The slip ring assembly of claim 1 wherein each of the contact rings has an electrical contact clip connected thereto.
9. The slip ring assembly of claim 1 wherein the distal end of each contact brush rides in a groove formed in the outer perimeter of the corresponding contact ring.
10. The slip ring assembly of claim 1 and further comprising a plurality of ring spacers carried on the contact ring supporting means on opposite sides of the contact rings.
11. A slip ring assembly, comprising:
a plurality of contact rings;
means for supporting the contact rings in spaced relation about a common axis;
a housing located adjacent the contact rings and configured to permit relative rotation between the contact rings and the housing;
a planar printed circuit board mounted to the housing; and
a plurality of contact brushes extending substantially perpendicular to the printed circuit board and each having a proximal end connected to the printed circuit board and a distal end slidably engaged with a corresponding one of the contact rings.
12. The slip ring assembly of claim 11 wherein the housing includes a pair of shells that enclose the contact rings and reference portion of the position encoder.
13. The slip ring assembly of claim 11 wherein the contact brushes apply a spring force to their corresponding contact rings.
14. The slip ring assembly of claim 11 wherein a portion of an electrical connector is mounted on the printed circuit board.
15. The slip ring assembly of claim 11 wherein the contact ring supporting means includes a generally cylindrical body.
16. The slip ring assembly of claim 11 wherein the distal end of each contact brush rides in a groove formed in the outer perimeter of the corresponding contact ring.
17. The slip ring assembly of claim 11 and further comprising a plurality of ring spacers carried on the contact ring supporting means on opposite sides of the contact rings.
18. The slip ring assembly of claim 11 and further comprising a position encoder having a signal generating portion mounted on the printed circuit board and a reference portion mounted on the contact ring supporting means.
19. The slip ring assembly of claim 18 wherein the signal generating portion of the position encoder is a Hall effect sensor mounted on the printed circuit board and the reference portion of the position encoder is a magnetic ring with a plurality of separate circumferentially spaced magnetic domain regions.
20. A slip ring assembly, comprising:
a cylindrical slip ring body;
a plurality of contact rings supported on the slip ring body in spaced relation about an axis of the slip ring body;
a plurality of ring spacers supported on the slip ring body on opposite sides of the contact rings;
a housing located adjacent the contact rings and configured to permit relative rotation between the contact rings and the housing;
a printed circuit board mounted to the housing;
a plurality of contact brushes each having a proximal end connected to the printed circuit board and a distal end slidably engaged with a corresponding one of the contact rings, the contact brushes applying a spring force to their corresponding contact rings;
a position encoder having a signal generating portion mounted on the printed circuit board and a reference portion mounted on the slip ring body; and
a portion of an electrical connector mounted on the printed circuit board.