The Adjustment of the Gap Between the Spindle and Bearing of CNC Machine Tool

CNC machine tools are high-precision, high-efficiency, and highly automated machine tools, in which the spindle is an important part of the CNC machine tool. As the core component of CNC machine tools, the spindle is responsible for the tasks of rotating workpieces and cutting.

1. The effect of adjusting the gap between the spindle and the bearing of the CNC machine tool

Too large or too small radial and axial clearances of the spindle bearings of CNC machine tools are the main reasons for the failure of CNC machine tools. If the gap is too large, the spindle will jump, and the turned workpiece will produce ellipses, round edges or ripples; if the gap is too small, the spindle will heat up and be damaged at high speed. When adjusting, first loosen the locking screw 5 and the nut 4, so that the inner ring of the bearing 7 moves to the right relative to the tapered journal of the main shaft. Due to the action of the tapered surface, the inner ring of the bearing produces radial elastic expansion, which reduces the gap between the roller and the inner and outer rings. After the CNC machine tool is properly adjusted, the locking screw 5 and nut 4 should be tightened. The clearance of bearing 3 can be adjusted with nut l. Under normal circumstances, it is only necessary to adjust the front bearing. Only when the required rotation accuracy cannot be achieved after adjusting the front bearing, the rear bearing can be adjusted. The rear bearing can adjust the axial clearance and precision of the main shaft.

2. Operation steps of adjusting front bearing of CNC machine tool

(1) Prepare a hook wrench, a hammer, and a screwdriver, open the headstock cover and place it stably.

(2) Hook the nut at the front end of the spindle with a hook wrench and turn it counterclockwise. If it cannot be pulled, use a hammer to lightly hit the hook wrench to loosen the nut.

(3) Loosen the locking screw, and then tighten the adjusting nut counterclockwise with a hook wrench (Figure 1-8). After adjustment, tighten the locking screw with a screwdriver and tighten the adjusting nut.

(4) Check the size of the spindle bearing clearance, turn it by hand, there is no blockage, and then measure the radial runout and axial movement of the spindle to make it ≤ 0 0mm, close the cover of the spindle box, and make the spindle run at high speed ih , Bearing temperature ≤ 60 ℃ can be.