Good lubrication can not only reduce friction, but also cool the bearings and parts on the shaft. After the rolling bearing clearance is adjusted, the friction will increase, and the heat generated will increase the temperature of the entire transmission system. If the heat cannot be dissipated in time, the heat will change the size of the transmission parts, which will affect the change of the rolling bearing clearance, generate more heat, and form a vicious circle. Therefore, for the rolling bearings with adjusted clearance, it is necessary to maintain good lubrication to reduce friction, and more importantly, use the continuously circulating lubricating oil to take away a lot of heat, control the temperature rise, and achieve the heat balance of the transmission system.