PURPOSE: To eliminate the need of troublesome work for changing driving/ transmitting means at the time of posture shifting of a rolling roll and to unnecessitate devices which had been necessary to that change.

CONSTITUTION: One end part of a transmission shaft part 12 is connected to the driving input part 4 of the rolling roll 2 through a rotatable joint part 10 and also the other end part of the transmission shaft part 12 is similarly connected to a driving device 7 such as a motor 23 through the rotatable joint part. This driving device 7 is provided on a traveling truck 43 which is freely traveled along guide rails 44. At the time of posture shifting of the rolling roll 2, the driving device 7 (traveling truck 43) executes approaching and separating motion corresponding to circular-arculate motion of the joint part between the driving input part 4 and the transmission shaft part 12.