Spindle mechanism of winding machine

A spindle mechanism of a winding machine, comprising:

• a spindle box, the spindle box is provided with a mounting hole;
• bearings, the bearings are respectively arranged at both ends of the mounting hole of the spindle box to form a front bearing and a rear bearing, each of the front and rear bearing comprises an inner ring and an outer ring;
• a spindle, the spindle is arranged to pass through the mounting hole of the spindle box and is rotatably positioned on the spindle box by means of the bearings, and a number of bearings in the front bearing is the same as a number of bearings in the rear bearing, and the outer ring of at least one of the front bearing and the rear bearing is not restricted in an axial direction so as to form a free end;
• and
• wherein a diameter of a middle portion of the mounting hole is smaller than a diameter at both ends of the mounting hole to form a limit structure of at least one limit step, and when the spindle is offset from the spindle box in the axial direction, the outer ring of the bearing at one end abuts against the at least one limit step, to restrict the spindle from being further offset, so as to restrict the bearing at the other end from being disengaged from the mounting hole of the spindle box.