Conveyor roll and process for its assembly
Conveyor rolls used in high temperature applications, and an end cap assembly for such rolls. The conveyor roll comprises a ceramic spool, an end cap and a tolerance ring. The end cap contains a metal ferrule and has an internal circumference adapted to fit over an end of the ceramic spool. A tolerance ring is interposed between each end of the ceramic spool and the end cap. The tolerance ring is composed of resilient metal having a plurality of circumferentially arranged corrugations. The conveyor roll can resist temporary overheating or blockage without damage.
1. Conveyor roll for high temperature applications comprising:
(a) a ceramic spool having ends and a radial surface;
(b) at each end of the ceramic spool, an end cap comprising a metal ferrule and having a certain internal circumference adapted to fit over an end of the ceramic spool; and
(c) interposed radially between each end of the ceramic spool and the end cap, an open tolerance ring of resilient metal comprising a smooth portion with a single radius, the tolerance ring having a curved dimension less than the internal circumference of the end cap and having a plurality of circumferentially arranged corrugations protruding in a single radial direction from the smooth, single radius portion.
2. Conveyor roll according to claim 1 , wherein the tolerance ring has a pitch lower than 20 mm.
3. Conveyor roll according to claim 1 , wherein the corrugations of the tolerance ring extend inwardly.
4. Conveyor roll according to claim 3 , wherein a plurality of open tolerance rings are interposed between each end of the ceramic spool and the end cap, and the openings of the tolerance rings are offset.
5. Conveyor roll according to claim 1 , wherein at least one of the tolerance rings is provided with at least one tab and in that the corresponding end of the ceramic spool is provided with at least one notch adapted to receive the at least one tab of the tolerance ring.
6. Conveyor roll according to claim 5 , wherein the at least one tab is oriented so that the end of the tab will cooperate with the wall of the notch closest to the end of the spool.
7. Conveyor roll according to claim 6 , wherein the tolerance ring is provided with at least two tabs and wherein at least one tab has an orientation opposite to at least another tab.
8. Conveyor roll according to claim 1 , wherein the end cap is provided with a step or a groove adapted to receive the tolerance ring.
9. Process for the assembly of a conveyor roll according to claim 1 , comprising the steps of
(a) fitting an open tolerance ring having a curved dimension less than the internal circumference of the end cap in the ferrule of an end cap;
(b) forcing each end of the ceramic spool into the end cap.
10. Process according to claim 9 , comprising a further step a′) of bending at least one tab of the tolerance ring inwardly and a step b′) of aligning the spool so that the at least one tab matches the corresponding notches of the spool.