Large-transmission-ratio multi-stage gear pair backlash amount detection device and detection method

The invention belongs to the field of machine manufacturing, and relates to a large-transmission-ratio multi-stage gear pair backlash amount detection device and a use method. The detection device comprises a torque angle sensor, a transition joint and a digital display dial indicator. One end of the torque angle sensor is connected with the transition joint; one end of the transition joint is connected with the transmission system input shaft, and the other end is connected with the torque angle sensor; provided is a transmission system output gear tooth surface pressure digital display dial indicator. A digital display dial indicator is pressed on the tooth surface of a transmission system output gear, a torque angle sensor rotating shaft is rotated in one direction to drive a transmission system input shaft to rotate, and rotation of the torque angle sensor rotating shaft is stopped at the moment of digital change of the digital display dial indicator; and the numerical values of the torque angle sensor an