Internal Worm Wheel 24 August 2017, 22:00 Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch it with your favorite video player! Internal worm wheel is the yellow ring. In fact it is a helical gear (60 teeth) engaging with pink worm (1 start). Power is transmitted to chain sprocket fixed to the worm. Transmission ratio: 60. « previous mechanism Roller Overrunning Clutch next mechanism » Oval Gear load comments Please enable JavaScript to view the comments.