The invention particularly relates to a middle roller sectional transmission device of a whole section box type
spinning frame, which is arranged on a rack of the
spinning frame, the rack comprises a middle
wall plate, the top end of the middle
wall plate is connected with a horizontal circular
machine beam, the horizontal circular
machine beam is formed by splicing and assembling a plurality of short circular
machine beams, and the middle roller sectional transmission device is arranged in the middle of the horizontal circular machine beam. The middle roller segmented transmission device comprises a motor mounting seat, a
servo motor, a planetary
reducer, a reduction gearbox and two couplings; the
servo motor is arranged on one side of the motor mounting seat, the rated output torque of the
servo motor is 6.2 Nm, the planetary
reducer increases the output torque of the servo motor in a ratio of 10: 1, the reduction gearbox increases the output torque of the planetary
reducer in a ratio of 4.1 times, the two couplings are arranged at the two ends of an output shaft of the reduction gearbox respectively, and the output torque of the whole middle roller segmented transmission device is 254.2 Nm. The length-
diameter ratio of transmission of the middle roller can be shortened, and the
torsional vibration phenomenon of the middle roller is avoided.