Worm Shaft Acceptable Backlash

How do you know the worm shaft is case hardened?

Are you sure the wear is on the worm and not on the worm nut?

Is the worm nut steel or brass? Is it a split nut?

1 Wormshaft wears little maybe microns-. Wheel teeth do- a lot more

2 Your Application will determine acceptable backlash limit.

Maybe your load is not a reversible movement. In that case your Wormwheel will carry the 100KW easily for many more years.

But you put me in doubt with your "+-"

Even with the "3 mm Backlash" in reversing drive maybe OK for many more years - noisily.

Can advise you Professionally.

mm

I agree with MUKULMAHANT. How much lash is tolerable can only be answered in the context of the application.

The curved worm and sector gear boxes use in the steering of American cars in the 60's and 70's had a lot of free play on either side of center but were tolerable when headed straight ahead. They eventually fell into disfavor with the adoption of the European style rack and pinion gear box.

By contrast astronomers using worm drives on celestial telescopes have zero tolerance for even the slightest lash because at magnifications of 500 to 750 times and more, even the slightest lash or periodic error is magnified by the magnification being used.

Likewise, feed screws on machine lathes and vertical mills cannot tolerate lash, especially on CNC driven operations.

Laughing Jaguar.