JPS643319A - Bearing device for back-up roll - Google Patents

Abstract

PURPOSE:To prevent metal plates and rolls from being damaged and heated by providing an one-way clutch so as to make the rotation at all time at circumferential speeds equal to plate passing speeds when a work roll is accelerated, and making the unresisted rotation around a shaft under interruption when no acceleration is required. CONSTITUTION:A shaft 22 rotatably supporting a back-up roll 21 via a roller 23, and a circular guide member 32 are provided so as to fasten the outer circumferential surface 32a onto the back-up roll 21. And an one-way clutch 33 having sprags 35 is provided between an inner circumferential surface 32b and the shaft 22. When the shaft 22 is drivingly rotated, the back-up roll 21 and the shaft 22 are locked by the wedging action of the sprags 35 so as to transfer torque. When the rotation is made by friction force at the time of plate passing, there is no need for the drive of a work roll 3, the shaft 22 is suspended so as to be rotated relatively with the back-up roll 21 to the reverse direction, the locking action by the sprags 35 is however released, thereby allowing the back-up roll 21 to be rotated unresistedly. This constitution therefore prevents metal plates and the work roll from being damaged at the time of again contacting to the metal plates, and also prevents the occurance of frictional heat during the period of plate passing time.