What type of bearing does the floating cam ring ride on?

• A. A cam ring that floats independently without bearing contact.
• B. Shelf-type bearing with a large clearance between bearing and ring.
• C. Ball bearing with no clearance.
• D. Plain bearing with tight fit.

Answer: (B)

The floating cam ring needs a bearing that allows it to move slightly and stay lubricated while it rotates. A shelf-type bearing provides a recessed surface for the ring to ride on and is designed with a deliberately large clearance between the ring and the bearing. That clearance lets the ring float freely, accommodates thermal expansion and any slight misalignment, and preserves oil film lubrication to reduce wear.

Other options don’t fit because they’d either provide no support or be too tight: a setup with no bearing contact would fail to support rotation and lubrication; a ball bearing with no clearance would be too rigid and wouldn’t tolerate the floating action; a plain bearing with a tight fit would bind and cause excessive friction and wear.