Other important quality control points for major lathe renovation and new machine renovation

1. Rust inspection: Each horizontal and vertical guide rail surface, main shaft, main shaft flange, and tail seat hollow sleeve.
2. Rust prevention measures must be taken for exposed non painted surfaces, such as cleaning and conducting rust prevention checks with lubricating grease. The scraping surface, screw rod, and bearing must be cleaned before assembly, and there must be no red lead powder, iron chips, or other dirty substances left; There is no dust or dirt on the inside of the electrical box and protective cover.
3. Leakage inspection: The spindle bearings and gears of the overhauled lathe must be kept lubricated. The axial screw rods and bearings of the overhauled lathe and the new lathe must be lubricated and equipped with cooling devices. Moreover, there must be no leakage at the joints, oil, water tanks, etc. during lubrication and cooling.
4. Machine tool noise, temperature rise, speed, and idle running test:
① The main shaft is continuously idle for 4 minutes at various speeds, with the highest speed running for no less than 2 hours. The idle running time of the entire machine is ≥ 16h, and simulation idle running tests are conducted on circular arc, thread, outer circle, end face, and other cyclic turning.
② After the temperature of the spindle bearing stabilizes, measure the bearing temperature and temperature rise. Rolling bearings: temperature ≤ 70 ℃, temperature rise ≤ 40 ℃; Sliding bearing: temperature ≤ 60 ℃, temperature rise ≤ 30 ℃.
③ The noise pressure level of the machine tool is ≤ 83dB (A) under idle running conditions, and there is no abnormal scream or impact sound from the machine tool. The feed motion in each axis direction should be smooth and free from obvious vibration, vibration, and crawling.
④ The continuous idle running test of the machine tool shows no faults, reliable and stable operation within the specified continuous idle running time.
5. Renovation of user replacement parts (including maintenance of machine tool parts): Due to the large number of renovation projects for lathe replacement parts, the main focus is on replacing spindle bearings, axial screw rods, axial motors, axial bearings, and systems.
① Replacing the spindle bearing: Since replacing the spindle bearing is to ensure the accuracy of processing the outer circle and end face, it is necessary to first inspect the noise of the spindle after replacing the bearing. If there are no abnormalities, the sound pressure level of the entire machine's noise should not exceed 83dB (A), and then conduct a machining accuracy inspection and inspect the surface roughness of the processed workpiece.
② Replacement of axial screw rod inspection: Check the accuracy of all directions to ensure that within the specified range, the running machine can achieve axial operation without abnormal impact sound and noise. Replacing the axial motor: As other projects have not been modified, the inspection only focuses on the noise caused by the running machine, and there is no abnormal impact or noise during axial operation. Check the axial reverse clearance to prevent the reverse difference from meeting the requirements during assembly.
③ Replacing axial bearings: In the case of replacing axial bearings, it is necessary to ensure that the reverse difference in the axial direction meets the requirements and check for any abnormal noise.
④ System replacement inspection: In the case of replacing the system, only the system function is inspected, whether there is an alarm phenomenon in the system, and at the same time, whether the test thread is normal (for lathes with encoders).