PURPOSE: To suppress the vibration by eliminating the clearance of a roll neck of a rolling mill, and simultaneously, to simply detach a roll by forming a prescribed clearance at the time of changing the roll.

CONSTITUTION: On a spindle coupling main body 19, a pressure cylinder mechanism 23 and an accumulating mechanism 32 are provided, and an operating fluid is supplied and accumulated through hydraulic couplings 24, 25 which can be attached/detached in the course of stopping of a roll, by which looseness is eliminated by a pressure piston, while eliminating the need for supplying the operating fluid during operation, vibration is prevented and rolling can be executed at a high speed. On the other hand, by discharging the operating fluid, a clearance required for a connection release is secured.