Adjustment of the radial and axial clearances of the main shaft bearings of the lathe

The commonly used processing machinery and equipment in the manufacturing industry is the lathe. However, during long-term operation, if the spindle of the lathe wears out or deforms, it will cause an increase in errors or changes in various clearances of the lathe, thereby interfering with the processing accuracy of the lathe and even affecting its productivity and operational safety. The article will provide a detailed explanation of the adjustment methods for the bearing clearance of the lathe spindle.

The spindle is a very crucial part of a lathe. During turning, the lathe spindle bears a heavy load. Therefore, when the front and rear bearings supporting the main shaft are not adjusted correctly, various defects will occur during processing. If the bearing clearance of the lathe spindle is too large, axial runout and radial runout will occur during the turning process of the spindle, which seriously affects the processing quality of the workpiece. On the contrary, if the bearing clearance of the lathe spindle is too small, the lathe spindle will be damaged due to high-speed rotation.

Therefore, when these abnormal phenomena occur during the lathe processing, the bearing clearance of the lathe spindle must be adjusted in a timely manner. If the bearing clearance of the lathe spindle is too large, axial runout and radial runout will occur during the turning process of the spindle, which seriously affects the processing quality of the workpiece. Next, we will introduce in detail the adjustment methods for the radial clearance and axial clearance of the main shaft bearings of the lathe.

Adjustment of the radial clearance of the main shaft bearing of the lathe

When the lathe is in the cutting process, due to the excessive radial clearance of the main bearing, when adjusting the radial clearance of the main shaft bearing, the main task is to adjust the clearance of the front bearing. Taking the C620-1 lathe as an example, when the front bearing of the lathe spindle uses a rolled bearing, the method for adjusting the radial clearance of the spindle bearing is as follows: Loosen the tightening screw of the front nut, turn the front nut to the right appropriately to move the inner ring of the tapered bearing along the axial direction, and then conduct a test run. If there is no overheating phenomenon of the lathe spindle at the maximum speed. It can be tightened by turning the main shaft by hand when there is no resistance sensation in the branch screws.

When the front bearing of the main shaft adopts a sliding bearing, taking the C620 lathe as an example, the adjustment method for the radial clearance of the lathe main shaft bearing is as follows: Loosen the top screw, moderately rotate the front nut in the unchanging ring to make the bimetallic bearing move axially, and keep the clearance between the lathe main shaft and the bearing between 0.02 and 0.03mm. After the lathe is adjusted, it needs to be test-run. If there are no abnormal conditions during operation, the top screws can be tightened.

After the above adjustments, the radial clearance of the lathe spindle bearing should be controlled within 0.006 to 0.01mm. Further inspection steps are required. The radial runout of the main shaft centering shaft diameter can be measured with a dial indicator. If the radial clearance of the lathe main shaft bearing is still too large, the clearances of the rear bearing and the front bearing of the main shaft should be adjusted.

Adjustment of the axial clearance of the main shaft bearings of the lathe

When performing turning operations on a lathe, if axial movement occurs in the main shaft bearing of the lathe, the main reason is that the clearance of the rear bearing of the lathe main shaft is too large. Therefore, when adjusting the axial clearance of the lathe main shaft, the operator mainly adjusts the size of the clearance of the rear bearing of the lathe main shaft.

The adjustment method for the axial clearance of the lathe spindle bearing is as follows: Loosen the support screw of the rear nut, rotate the rear nut to the right, move the inner ring of the conical rolling bearing along the axial direction, and at the same time reduce the clearance between the lathe spindle shoulder support, thrust ball bearing and rear bearing housing. Then conduct a test run for inspection. If there are no abnormalities in the operation of the lathe, just tighten the support screws.

When adjusting the clearance of the main shaft bearings, it is necessary to adapt to an appropriate clearance that is compatible with the maximum speed of the lathe. Also, it is important to separate the adjustment of each shaft from the meshing shaft to avoid interference. When the bearing clearance of the lathe spindle is too large or too small, it can be adjusted with an adjusting screw. The axial movement should be controlled within 0.02mm, and the clearance between the main shaft and the bearing can be controlled within 0.01mm.

The article mainly introduces the adjustment method of the bearing clearance of the lathe spindle. By browsing the full text, you can understand that the spindle is a very crucial part of the lathe. During turning, the lathe spindle bears a very heavy load. Therefore, when the front and rear bearings supporting the main shaft are not adjusted correctly, various defects will occur during processing. If the bearing clearance of the lathe spindle is too large, axial runout and radial runout will occur during the turning process of the spindle, which seriously affects the processing quality of the workpiece. On the contrary, if the bearing clearance of the lathe spindle is too small, the lathe spindle will be damaged due to high-speed rotation.