Throwout bearing self aligning or standard

This might be a completely stupid question, but what is the difference between a "self aligning" and "thrust" throwout bearing? and what are the pros/cons to using either?

I'm familiar with what a thrust bearing is, ( flat disc of radially oriented needle bearings )

I imagine that the "self aligning" type have some sort special front race with a ball carriage bearing but I'm just guessing.

Do self aligning ones last longer or chatter less or is it just a different/new design?
Author: admin