What is the bearing shell? The difference between the bearing and rolling bearing

Bearing in the industrial society is a kind of indispensable components, with the bearing after people can turn a movement pattern into another, or to reduce the friction between two contact surfaces, but the bearing is known to all. Bearing shell are probably most people don't know, you know what bearing shell is? Compared with bearing it what's the difference? China bearing network according to understand, tell you what is the bearing shell? What's the difference between bearing and rolling bearing?