Patent ID: 8016487

Claim:
A bearing structure, comprising: a rotational element having a generally cylindrical bearing surface, and a plurality of detents defined upon and extending in from the cylindrical bearing surface, wherein the generally cylindrical bearing surface comprises a plurality of bearing regions and a plurality of detent regions; a support member; at least three bearing assemblies, wherein each of the bearing assemblies comprises a cam member rotatably mounted to the support member, each of the cam members comprising a cam surface having a profile that contacts the cylindrical bearing surface and rotates away from a home position when the cam is rotatably positioned to meet one of the bearing regions of the cylindrical bearing surface, and does not contact the cylindrical bearing surface when the cam is rotatably positioned to meet one of the detent regions of the cylindrical bearing surface, and means for rotationally biasing the cam member toward the home position; and means for rotating the rotational element in relation to the support member.