Automatic press-fitting tool for gearbox gear wheel of motor train unit and press-fitting pressure holding detection method

An automatic press-fitting tool for a gearbox gear wheel of a motor train unit comprises a positioning sleeve, a support sleeve, an axle end protective cover, an axle end protective block, a pull rod, a pull rod stop nut, a thrust pump oil cylinder, a press block, an inner push cylinder, an outer push cylinder and a sensor, wherein the positioning sleeve, the inner push cylinder, the support sleeve and the axle end protective cover are all in clearance fit with an axle; the inner push cylinder is mounted on the rear of the positioning sleeve, the inner wall of the inner push cylinder is in clearance fit with the support sleeve, and the inner wall of the support sleeve is in clearance fit with the axle end protective cover; the axle end protective block is fixed at the axle end of the axle and tightly presses the support sleeve and the axle end protective cover; the push rod is mounted in a central hole of the axle end protective cover, and penetrates backwards through the press block and a central hole of the thrust pump oil cylinder; the thrust pump oil cylinder is first fastened to the press block by a bolt and then pressed against the axle end by the pull rod stop nut; and the displacement sensor is mounted on the outer push cylinder, and an expansion pump oil pipe is connected with a gear oil inlet hole. When the gear wheel is press-fitted by the tool, the labor intensity is reduced, the press-fitting process of the gear wheel is monitored in real time, and the press-fitting quality of the gear wheel is ensured.