Common causes and elimination methods of errors in gear shaping machining

Writer： admin Time：2024-05-06 14:15:57 Browse：28℃

Causes related to machine tools

The axial displacement of the worm gear in the worm gear pair of the workbench and tool holder is too large;

Due to long-term use, the worm gear pairs of the workbench and tool holder have worn out tooth surfaces, resulting in excessive meshing clearance;

The radial feed screw and spring have insufficient elasticity during cutting processing;

In the worm gear pair of the workbench and tool holder body, especially the tooth surface of the worm gear, there is abrasion and burrs on the tooth surface;

The contact between the worktable spindle and the 1:20 conical guide rail of the worktable is too loose, causing the worktable spindle to float during rotation and poor centering;

Make the knife unstable;

The insertion strip of the tool holder rack sleeve is loose;

The radial runout of the equal radius (r79 ± 0.005) part of the automatic radial feed cam exceeds the tolerance;

Gear shaping cutter shaft φ 31.743 There is burrs on the cylindrical surface, and the gear cutter is skewed or misaligned after being fixed;

The accuracy of parts in the machine tool transmission chain, especially the worktable worm gear and tool holder worm gear, has been lost;

Among the geometric accuracy items of machine tools, the items that exceed the tolerance range have a significant impact, including:

End face runout of the workbench

Radial runout of the centerline of the worktable cone hole

Radial runout of the tool holder body tool spindle centering diameter

Elimination method:

Readjust the axial movement of the worm gear to ensure that the displacement is within the range of 0.003 to 0.008;

Wear and adjust the gasket to ensure that the meshing clearance of the worm gear pair is within the range of 0.02-0.05. If necessary, repair the worm gear and reassemble the worm gear;

Adjust the spring force;

Grinding with oilstone or scraping with a scraper, if the damage is significant, consider re rolling and grinding the teeth to restore the accuracy of the worm gear. At this time, the worm gear should be reconfigured;

Scrape the conical guide rail surface so that the contact between the conical guide rail surface is harder than that of the flat guide rail, and the contact is required to be even. When scraping, it is required to use a 500mm pry bar to rotate the workbench with a force of about 100N, and there should be no feeling of being too light or too heavy during one rotation;

Adjust the cutting mechanism to ensure that the cutting amount is within the range of 0.3-0.5 and that the resetting accuracy of each cutting is not greater than 0.01mm;

Adjust the inlay strip;

Re grind the cam to within 0.005 range;

Use an oil stone to remove burrs and burrs;

When repairing the worm gear and seriously losing accuracy, consideration should be given to replacing the worm gear;

Repair the relevant parts of the workbench and tool holder body.