Vertical Lathe Spindle Clearance Adjustment Procedure

1. Preliminary Preparation
① Carefully withdraw the entire assembly-comprising the worktable, spindle, and inner bearing ring-from the spindle bore; place it securely on a dedicated platform, ensuring the spindle axis remains oriented vertically upward.
② Remove the outer bearing ring from the spindle bore located within the worktable base, and thoroughly clean all components to remove oil residue, metal chips, and impurities.

2. Loosening Locking Components
Loosen and remove the set screws. Then, loosen the two retaining nuts (designated as Nut 3 and Nut 5) responsible for clamping the inner bearing ring, allowing the inner ring to move freely in an axial direction along the tapered surface of the spindle.

3. Adjusting the Clearance
① Reinstall the outer bearing ring into its mounting position. By tightening the retaining nuts, drive the inner bearing ring axially along the tapered surface; the tapered geometry will induce a radial expansion of the inner ring, thereby reducing the clearance between the rollers and the inner/outer rings.
② Monitor the clearance continuously during the adjustment process. For standard vertical lathes, the final radial clearance should be controlled within the range of 0.006 to 0.01 mm to satisfy the required precision standards.

4. Locking and Securing
Once the target clearance has been achieved, tighten the set screws to lock the positions of the two retaining nuts, thereby preventing the nuts from loosening during operation-which could lead to a recurrence of excessive clearance.

5. Equipment Reassembly
Reinstall the adjusted outer bearing ring back into the spindle bore within the worktable base. Then, reinstall the entire worktable assembly (including the spindle) back into the machine tool.

6. Post-Adjustment Verification
Verify the successful completion of the adjustment by following the standard validation sequence: "Static Inspection → No-load Run-in and Temperature Rise Test → Cutting Precision Verification." Specific methods for these verification steps can be referenced in previous documentation.

Note: If the machine is a CNC vertical lathe, it is also necessary to recalibrate the spindle's home position (zero point) after adjustment to prevent any positioning deviations from compromising machining accuracy.