Machining center spindle repair instance and fault elimination process

Machining center spindle repair instance and fault elimination process - 2020 10 - Vertical machining center bore precision drops, cylindricity error, spindle fever, noise is big, but with the hand touch the spindle rotational resistance is smaller. ( 1) Failure analysis: disintegration of spindle assembly inspection, found the cause of the problem are as follows: (1) the main shaft bearing grease in mixed with dust and moisture, this is because the processing center with compressed air free of fine filtration and drying device, so a small amount of dust and moisture at pneumatic dust blowing into the main shaft bearing grease inside, cause poor lubrication, causes fever and noisy; Spindle taper hole location within the surface with a little bruised, cone hole with the handle cone bad, there are traces of eccentric; (2) the front bearing preloaded force drops, bearing clearance greatens; (3) the spindle automatic clamping part of the disc spring fatigue failure of an organization, the cutting tool are not fully tighten, with a little rash move. ( 2) Troubleshooting: replacement front bearing and grease, adjust bearing clearance, axial clearance is 0. 003 mm, radial clearance and 0. 002mm； Self-made simple tool, manual grinding spindle inner cone hole, the surface with coating inspection, to ensure the handle and the spindle centering taper hole of contact area is more than 85%; Replace the disc spring. Will repair the spindle to back to the spindle box, radial runout were examined with a dial indicator, proximal less than 0. 006 mm and 150 mm distal less than 0. 010mm。 Spindle temperature rise and noise to normal processing, processing accuracy satisfies the requirement of processing technology, troubleshooting. ( 3) Improvement measures: (1) increase the fine filtration and drying device, compressed air filters regularly drainage, clean or replace filter on a regular basis; (2) check the spindle taper hole, the handle of the cleaning and cooperate with the condition, check whether the air dryer work normally; (3) reasonable arrangement of process, the abrupt change to avoid the material removal rate; (4) it is strictly prohibited to overload operation, defective shall promptly repair service, shall not be run in spite of illness. Spindle parts of the tie rod ball damage ( 1) Fault phenomenon: vertical machining center spindle tool automatic clamping mechanism of tie rod ball and handle and tighten screw tail cone are often damaged. ( 2) Failure analysis: check, found that the main shaft pine knife sword out of action with manipulator moves. This is due to the limit switch block iron in gas-liquid boosting cylinder cylinder tail, although the cylinder piston action in place, pressure cylinder piston movement did not reach the designated position, the manipulator in the case of the handle is not completely loosen to draw his sword, damage the tie rod ball and tighten screw. ( 3) Fault handling: cleaning the pressurized cylinder, replace the sealing ring, to booster cylinder oil, air pressure adjustment to 0. 5 to 0. 8 mpa, fault disappear after trial. ( 4) Improvement measures: (1) regular inspection and cleaning gas-liquid boosting cylinder, automatic monitoring tool clamping mechanism of running status of each part, in a timely manner to eliminate the problems; (2) check regularly adjust the pneumatic and hydraulic system pressure, inspection of the hydraulic oil, such as the oxidation, it should be replaced in a timely manner. Spindle parts positioning key damage ( 1) Fault phenomenon: vertical machining center tool change impact noise big, end of the handle rotation upon the positioning of the key local deformation. ( 2) Failure analysis: noise mainly appear in the manipulator inserted knife phase, fault for spindle must stop position error and identified as the reference point drift tool changer. This machine USES hall element to detect the directional, cause no spindle must stop position may be the cause of the spindle must stop motion electrical system parameter changes, positioning unreliable or spindle radial runout super poor. First check the installation position of hall element, found and fixed screw loosening, manipulator when inserted knife handle keyway not for spindle front position key, positioning key is damaged. Spindle tool change the installation position of reference points close to the switch also have loose phenomenon, make the tool change reference point trace down, the handle when the spindle taper hole plug cone directly impact the spindle centering cone hole, produce sound. ( 3) After the fault handling: adjust the installation position of hall element and tighten the locking glue. To readjust the spindle tool change the installation position of reference points close to switch, replace the spindle front position key, fault disappear. ( 4) Improvement measures: check regularly clean line must stop motion and main reference point positioning device in the knife, observe the handle to insert the state when the spindle taper hole, to eliminate the problems in a timely manner. （ Source: web)