SGoogs1780

All the time. Very large shafts sometimes. It's fun to ride the big shafts. Here's a photo of me and my college roommate riding a huge shaft together: http://imgur.com/6k9sHno.

That was my sophomore year, I've since come across much larger shafts, but don't have any photos, sorry. For my thesis I borrowed a professor's boat and performed tests on his shaft. It involved measuring the loads in the shaft. I even got it published, and presented the things I did to his shaft at a shafting symposium. While I was there, I saw a number of older engineers present their work with shafts, It was quite interesting.

I work in a field where you can hear the phrase, "have you taken a look at the vibration loads in the shaft at large thrust loads?" without batting an eye. If you want to make shaft jokes here, you better step up your game, son.

I can't speak to any industry other than Marine Engineering, but ball bearings aren't particularly common at all in my field. They don't handle axial loads very well, and I tend to come across shafts that carry pretty high thrust loads in addition to torque loads. The obvious example being propeller shafts. Not to mention I deal with water-tight bearings pretty frequently, and ball bearings are definitely not water-tight.