Rotary flying shears are mainly installed on small and wire tandem rolling units for cutting head, tail and ruler.
FIG. 9-28 shows a schematic diagram of a rotary flying shearing machine for continuous operation. The continuously operating motor 4 controls the start, shear and braking of the shear mechanism through a pair of high-torque, low-inertia pneumatic clutches 2 and brake 1. The main feature of this flying shear is connecting the transmission shafts of the upper and lower tool frames through four equal diameter gears, Z1, Z2, Z3 and Z4. Thus, in the case of the same rotation radius of the tool holder, the diameter of its transmission gear is only 1/2 of the diameter of the gear driven by two gears (see figure 9-2), which greatly reduces the rotary momentum of the fly shear and reduces the load of the clutch and brake. In fact, in order to improve the linear velocity of the blade during shear, when the radius of rotation of the tool holder increases, the moment of inertia of gear diameter also decreases. Therefore, this shearing machine is suitable for high shear velocity, with a maximum linear velocity of 16-20m/s. In addition, the adjustment of side clearance of transmission gear is carried out through eccentric cylinder on gear Z1 and eccentric shaft on Z2 and Z3, which is simpler and more convenient than the main auxiliary gear structure shown in FIG. 9-26.
With the development of the control technology of low inertia motor and reducer, the rotary flying shearing machine with starting work has been widely used. The flying shears have the advantages of simple structure, accurate stop position, small shearing length error and less maintenance work.