The function of automobile bearing should be support, that is, the literal interpretation is used for bearing, but this is only part of its function, supporting the essence is to bear radial load. It can also be understood as it is used to fix the axis. It is the fixed axis that enables it to rotate only and controls its axial and radial movement. The consequence of the motor without bearing is that it can not work at all. Because the shaft may move in any direction, while the motor is working, it requires that the shaft can only be rotated. Could not achieve the transmission effect, speaking theoretically not only that, the bearing will also affect the transmission, in order to reduce this effect must achieve good lubrication in the bearings of high speed shaft, the bearing itself has some lubrication, called pre lubricated bearings, and most of the bearings must be responsible for the lubricating oil in the high-speed operation, because friction will not only increase the energy consumption, more terrible is very easy to damage the bearing. The idea of turning sliding friction into rolling friction is one-sided because there is something called a sliding bearing.