The difference with cam: eccentric wheel itself is a kind of cam, because the action requirements of cam are different, the curve form used is not the same, the installation position requirements are not the same, the way of cam is also different, so there are many ways of cam, simply speaking, it is not circular and rotates around the center, almost all of them are cams. And the cam is not necessarily eccentric, such as an oval, around the center of rotation, but also a cam.