Patent attributes
A hearth roll apparatus for feeding a strip sheet in an annealing furnace is disclosed. The hearth roll apparatus includes a ceramic tube which is provided inside the annealing furnace to contactingly feed a strip sheet, a roll shaft which is coupled to a first end of the ceramic tube and extends across the annealing furnace through the ceramic tube, a tube fixing sleeve which is coupled to a second end of the ceramic tube and through which a portion of the roll shaft is inserted, and a tension generating unit which interlocks with the roll shaft and the tube fixing sleeve and supplies a tensile force for stretching the roll shaft in a longitudinal direction. Accordingly, thermal deformation like creep buy which the roll shaft is bent down is minimized, and a line speed of the strip sheet can be increased by high-speed rotation of the hearth roll.
