Clearance adjustment of cylindrical roller bearings with tapered bore and confirmation after installation
After installing the spindle bearing, confirm whether it can operate normally through a test run. Especially in the case of grease lubrication, in order to ensure that the grease is evenly distributed inside the bearing, sufficient running-in operation is required. The general operation inspection steps are as follows: a Confirm whether there is contact between the shaft and the bearing seat or cover, and whether the gap is consistent. b For manually rotatable machinery, first manually confirm whether there is abnormal noise and whether there is blockage. c For large machinery that cannot be manually rotated, try to start at a low speed, and confirm item b above. d The above confirmation is not abnormal, and the rotation speed can be increased to the normal rotation speed in order to confirm whether the temperature increase is in line with the normal state. e Continue to carry out a long-term test run to confirm whether there is any loose bolts, nuts, oil or grease leakage, or noise. After trial operation, try to extract lubricant to confirm that no foreign matter enters. f After confirming the above items, enter the working state. The main reason for disassembling machine tool spindle bearings is periodic decomposition or mechanical failure. When disassembling, I hope to confirm the mechanical condition at this time as a material for future improvement. Especially in the event of a failure, you can find the key points to solve the failure in the disassembled state, and you need to do the following investigations. a. Is there any abnormality in the installation state of the bearing? b Residual amount of lubricating oil and grease and degree of contamination (sample taken in advance) c Matching state of the inner ring and outer ring d Failure state of the bearing In addition, when disassembling, please check the following points in advance Perform analysis. a Bearing removal method b Cooperating conditions c Disassembly tool. [Clearance adjustment of tapered bore cylindrical roller bearings] The internal clearance of tapered bore cylindrical roller bearings can be adjusted by the thickness of the spacer. The operation sequence is as follows: a Confirm the conical part of the shaft. 80% contact with liquid applied to the cone. b Put the inner ring with rollers into the cone of the shaft lightly (Figure 9.8) c Put the outer ring horizontally fixed shaft d Put the measuring end of the dial indicator at the center of the outer ring outer diameter e Press the outer ring from above, left and right Turn to zero the dial indicator. f Press the outer ring upward at a 180-degree symmetrical position (just below) at the measuring end, and turn it left and right to read the maximum value (Figure 9.9) g Rotate the shaft approximately every 30 degrees, measure the radial clearance, and determine the measured average value. For △Rh, measure the length to the end face of the inner ring and the shaft shoulder with a block gauge (Figure 9.10). i The variable position is the average of the measured values u200bu200bof 5~6 positions and is determined as j. The thickness of the cushion is determined by formula 9.3. (Equation 9.3): The average pad thickness ΔR measured according to step i: the measured radial clearance Δ: the target radial clearance after installationu0026#1048655; e: the shrinkage rate of the outer ring D: the outer ring outer diameter ( mm) De: inner diameter of outer ring (mm) Dh: outer diameter of housing (mm) u0026#1048647;: interference of outer ring k Correct the thickness of the spacer l Remove the inner ring with rollers from the shaft , At this time, avoid vigorously hitting the inner ring. It can be easily removed with a dedicated disassembly tool. m Install the spacer and the bearing on the shaft. n Measure the radial clearance again to confirm that the radial clearance has reached the target value (Figure 9.11). 9.2.4 Confirmation after installation Use the method exemplified in 5-3 Preload Measurement (P.14) to confirm whether the predetermined preload is loaded.