I know on mine, the fine screen over the filter just hinges open so you can dump the fine particles out of that pleated part. The whole thing is washable, which does have to be done to keep it from clogging, I find.
I agree, it looks like a handle on the wheel, but if you look at the motor half there is a gear like piece that mates with another on filter half. This looks like it has what I have read about where the wheel turns to clean the filter as the cord winder rewinds the cord. Pretty ingenious to me.