What should I do if the spindle heats up in the vmc cnc and the rotation accuracy decreases?
Question: The accuracy of my vmc cnc axis is not very good. Is it the manufacturer’s fault if the fault occurs?
Answer: There are frequent fits and frictions between components, so it is normal for failures to occur. No manufacturer can guarantee that other machine tools will not fail. Especially the main working part of the machining center spindle is often affected by the cutting force, plus the basic In the state of high-speed processing, the possibility of failure is relatively high, so don't panic if there is a failure, take out your purchase agreement or instruction manual, check the date of purchase, and contact the manufacturer for after-sales within the scope of after-sales. Of course, you It is best to have a maintenance worker, and these small problems can be solved by telephone communication.
Question: Hello, my vertical machining center has decreased boring accuracy, cylindricity is out of tolerance, the spindle is heated, and the noise is loud, but the rotation resistance of the spindle is small when the spindle is moved by hand, what should I do?
1. Failure analysis. The main shaft components were disassembled and inspected, and the reasons for the failure were found as follows: ①Dust and moisture were mixed in the main shaft bearing grease. This is because the compressed air used in the machining center has no precision filter and drying device, so a small amount of dust and water vapor flee in during the pneumatic chip blowing The lubricating grease in the spindle bearing causes poor lubrication, resulting in heating and noise; the positioning surface of the taper hole in the spindle has a little bump, the taper hole and the taper surface of the tool holder are poorly matched, and there is a slight eccentricity; ②The preload of the front bearing decreases, and the bearing The clearance becomes larger; ③Part of the disc spring in the spindle automatic clamping mechanism fails due to fatigue, the tool is not fully tightened, and there is a little movement.
2. Troubleshooting. Replace the front bearing and grease, adjust the bearing clearance, the axial clearance is 0.003mm, the radial clearance is ±0.002mm; self-made simple tools, hand-grind the positioning surface of the spindle inner taper hole, check with the coloring method to ensure that the tool holder and The contact area of the spindle centering taper hole is greater than 85%; replace the disc spring. Put the repaired spindle back into the spindle box and check the radial runout with a dial gauge. The proximal end is less than 0.006mm, and the distal end 150mm is less than 0.010mm. Trial machining, the spindle temperature rise and noise are normal, the machining accuracy meets the requirements of the machining process, and the fault is eliminated.
3. Improvement measures:
①Add compressed air fine filtration and drying device, the filter should be drained regularly, and the filter element should be cleaned or replaced regularly;
②Check the cleanliness and coordination of the spindle taper hole and tool holder at any time, and check whether the air dryer is working properly;
③ Reasonably arrange the processing technology to avoid sudden changes in material removal rate;
④ Overload operation is strictly prohibited. If there is a fault, report for repair in time, and operation with disease is not allowed.
