DRUM TYPE FLYING SHEARING MACHINE

PROBLEM TO BE SOLVED: To make a gear compact, reduce the inertia of a drum drive system and improve a shearing function by arranging a synchronous rotary mechanism using a double helical gear. SOLUTION: When a rotary drive source 45 is operated to rotate a lower drum 42, the torque of the drum 42 is transmitted to an upper drum 41 via the second double helical gear 49, the first double helical gear 48 and a helical spline 47. When a helix angle exceeds 0 but is equal to or less than 10 degrees, a thrust load generated with the helical spline 47 substantially drops, and even when the upper drum 41 and the lower drum 42 are driven for rotation, a cutter clearance disturbance is reduced. resulting in the precise cutting of a sheet metal.