Basic protective measures to ensure the accuracy of double-row deep groove ball bearings Before installation, the bearings should be cleaned with gasoline or kerosene, used after drying, and ensure good lubrication. Double-row deep groove ball bearings are generally lubricated with grease, but also can be lubricated with oil. When using grease lubrication, the grease with excellent performance such as no impurities, anti-oxidation, anti-rust and extreme pressure should be used. The filling amount of grease should be 30%-60% of the bearing and bearing housing volume, and should not be too much. The double row deep groove ball bearing with sealed structure has been filled with grease and can be used directly by the user without cleaning. When the bearing is installed, the bearing must apply equal pressure on the circumference of the end face of the ferrule, press the ferrule in, and do not directly hit the end face of the bearing with tools such as a hammer to avoid damage to the bearing. In the case of a small amount of interference, the end face of the bearing ring can be pressed with a sleeve at room temperature, and the sleeve can be hit with a hammer head to press the ring evenly through the sleeve. If mass installation, hydraulic press can be used. When pressing in, it should be ensured that the end face of the outer ring and the end face of the shoulder of the shell, and the end face of the inner ring and the end face of the shaft shoulder are pressed tightly, and no gap is allowed.

(1) Measure the size of the shaft and the bearing seat hole to determine the matching accuracy of the bearing. The matching requirements are as follows: the inner ring and the shaft adopt an interference fit, and the interference amount is 0~+4μm (0 in light load and high precision) ;The outer ring and the bearing seat hole adopt a clearance fit, and the clearance amount is 0~+6μm (but when the free end bearing uses an angular contact ball bearing, the clearance can also be increased); the surface roundness error between the shaft and the seat hole is less than 2μm, double The parallelism of the end face of the spacer used in the row deep groove ball bearing is below 2μm, the runout of the inner end of the shaft shoulder facing the outer end face is below 2μm; the runout of the bearing seat hole shoulder to the axis is below 4μm; the inner end of the main shaft front cover faces the axis. The beating is below 4μm.

(2) Installation of the front bearing at the fixed end on the shaft: Thoroughly clean the double row deep groove ball bearing with clean cleaning kerosene. For grease lubrication, first inject an organic solvent containing 3% to 5% grease into the bearing for degreasing After cleaning, use an oil gun to fill a certain amount of grease into the bearing (accounting for 10% to 15% of the bearing space volume); heat the bearing to raise the temperature to 20 to 30°C, and use a hydraulic press to install the bearing into the shaft end; The sleeve is pressed on the shaft and pressed against the bearing end face with suitable pressure to make it axially positioned; the belt of the spring scale is wound on the outer ring of the bearing, and the specified preload is checked by measuring the starting torque to see if there is a large change (Even if the double row deep groove ball bearing is correct, the preload may change due to the deformation of the fit or the cage)