Replacement

Hello! It looks like the worm gear is stripped out. That cannot be repaired or replaced, unfortunately, and it means you will need a new operator entirely.

We can help, but I will need you to remove the existing operator from the window and show me a clear picture of the full mechanism without obstruction. Right now your photos only show the base, which is not enough to go by.

Please let me know if that would be possible, or if you had any follow up questions. We're always here to help!

As I mentioned previously, this worm gear cannot be repaired or replaced. These are machine pressed at the factory and it would not be possible to install a new one into the old operator. No company sells these components for that reason and you will not be able to find them anywhere on the market. 

Even ignoring all that, the gears on the operator are probably stripped out, too. Otherwise this wouldn't have come out like it did. In other words a bad worm gear isn't the only damage you're looking at. 

The only option available to you is to replace the operator. Your next step should be to remove the original so that we may identify a potential match in our inventory.

Too much of it is obscured at this point in time. Right now I can only see the base, but there are dozens of different balances that use that same exact style. The key detail here is going to be the arms that physically open and close the window. I need to see those as clearly as you can manage. Figure that that the more they're obscured, the less likely I'll be to find a match.