The invention relates to a large torque reduction box for a withdrawal and straightening
machine. One or more stages of cylinder
gear transmission sets, a
tail stage taper gear, a
tail stage gear shaft, an output large gear and an output hollow shaft are arranged in a box, a motor
flange is arranged on one side of the box, an input gear shaft extends into the box from the motor
flange, the part, outside the box, of the input gear shaft is connected with a coupler, a
tooth part of the part, inside the box, of the input gear shaft is in transmission connection with the one or more stages of cylinder
gear transmission sets, a cylinder gear shaft of the last stage of cylinder
gear transmission set in the one or more stages of cylinder gear transmission sets is provided with a small taper gear,the small taper gear is meshed with a
tail stage large taper gear connected to the tail stage gear shaft in a sleeving manner, and the
tooth part of the tail stage taper gear is meshed with an outputlarge gear connected to the output hollow shaft in a sleeving manner. The large torque reduction box is simple in structure and capable of effectively giving consideration to the high speed ratio andthe large torque.