Method for extending the campaign life of stabilizers for a coating line
A steel processing line includes a dip tub and a stab roll. The dip tub is filled with a quantity of molten metal. At least a portion of the stab roll is submerged in the quantity of molten metal. The stab roll includes two journals. Each journal is received by an opening defined by a roller sleeve including a ceramic or refractory material. The roller sleeve is disposed between each journal and a bearing block. An inner dimension of each roller sleeve and an outer dimension of each respective journal defines a clearance. The inner dimension of each roller sleeve and the outer dimension of each respective journal is configured such that the clearance persists as the stab roll and the pair of roller sleeves are heated by the molten metal. Alternatively, inserts are fastened to an outer surface of each journal in lieu of the roller sleeves.
1. A bearing assembly for use in a coating line, wherein the bearing assembly is configured to support a first journal of a roll relative to a fixture of a dip tub, wherein the bearing assembly is configured for submersion in molten metal, wherein the bearing assembly consists of:
(a) a bearing block, wherein the bearing block defines an opening therein; and
(b) a roller sleeve, wherein the roller sleeve is disposed within the opening defined by the bearing block between the bearing block and the first journal of the roll, wherein the roller sleeve is configured to rotate relative to the bearing block to reduce wear on the first journal, wherein the roller sleeve defines a gap between an inner surface of the roller sleeve and an outer surface of the first journal.
2. The bearing assembly of claim 1 , wherein the gap between the inner surface of the roller sleeve and the outer surface of the first journal is sized to permit at least some lateral movement of the roller sleeve relative to the roll.
3. The bearing assembly of claim 2 , wherein the gap between the inner surface of the roller sleeve and the outer surface of the first journal is sized to prevent ingress of molten metal between the inner surface of the roller sleeve and the outer surface of the first journal.
4. A roller assembly, wherein the roller assembly is configured for submersion in molten metal, wherein the roller assembly comprises:
the bearing assembly of claim 1 , wherein the roll includes a rolling portion and the first journal extends axially from the rolling portion.
5. The roller assembly of claim 4 , wherein the first journal includes threading.
6. The roller assembly of claim 5 , wherein the inner dimension of the roller sleeve includes threading corresponding to the threading of the first journal.
7. The roller assembly of claim 6 , wherein the threading of the first journal defines a first pitch direction, wherein the roll further includes a second journal having threading that defines a second pitch direction.
8. The roller assembly of claim 7 , wherein the first pitch direction is opposite relative to the second pitch direction such that the threading of the roller sleeve is configured to remain engaged by the threading of a select one of the first journal and the second journal as the roll is rotated in a predetermined direction.
9. The roller assembly of claim 7 , wherein the first pitch direction corresponds to a right handed threading, wherein the second pitch direction corresponds to a left handed threading.
10. The roller assembly of claim 4 , wherein the roller sleeve comprises a ceramic material.
11. The roller assembly of claim 10 , wherein the ceramic material is substantially inert when submerged in the molten metal.
12. The roller assembly of claim 10 , wherein the ceramic material has a low coefficient of thermal expansion.
13. The roller assembly of claim 10 , wherein the ceramic material is configured to resist wetting of the molten metal.
14. The roller assembly of claim 10 , wherein the ceramic material comprises a SiAlON ceramic.
15. The roller assembly of claim 4 , wherein the roller assembly is submersed within a dip tub, wherein the dip tub includes a refractory container filled with a quantity of molten metal.
16. The roller assembly of claim 4 , wherein the first journal defines a square lateral cross-sectional shape, wherein the opening of the roller sleeve defines a shape corresponding to the square lateral cross-sectional shape of the first journal.
17. The roller assembly of claim 4 , wherein the first journal defines a cylindrical shape, wherein the opening of the roller sleeve defines a cylindrical shape corresponding to the cylindrical shape of the first journal.
18. The roller assembly of claim 4 , wherein the roll is rotated by friction between an exterior of the roll and a steel sheet moving through a dip tub.
19. The roller assembly of claim 4 , wherein the bearing block comprises a ceramic material.