PURPOSE: To simplify structure, to obtain large driving power and smooth motion of rolling mill by providing a piston cylinder device and a geared transmission system including a rack/pinion mechanism for transmitting the reciprocating motion of a piston rod to the gears of a fixed position rolling roll.

CONSTITUTION: The piston cylinder device 41 and a rack gear 42 are arranged perpendicularly to rolling rolls l, 2 and horizontally. When the piston cylinder device 41 is operated and its piston rod 411 is reciprocated, a pinion 44 and large diameter gears 45 are simultaneously revoled, further, gears 46 on the roll shafts 11 are respectively reciprocally revolved and the fixed position rolling roll 1 is reciprocally rotationally driven. Both upper and lower rolling rolls 1, 2 are connected by an interlocking mechanism 5. In this way, large driving power is obtained, the rolling rolls 1, 2 are revolved by interlocking and smooth rolling is executed. Further, noise and vibration during rolling are reduced.