Precautions for plane bearing maintenance
Precautions for plane bearing maintenance
1. Selection and control of shaft and bearing housing tolerance: the bearing shall rotate flexibly without blocking after being pressed into the plane bearing. If there is obvious inflexibility in rotation, it indicates that the size of the shaft is too large and the tolerance should be lowered. If the shaft has obvious "sand" feeling after being pressed into the shaft, it may be that the tolerance of the shaft is too large or the roundness of the shaft is not good. Therefore, roundness should also be controlled when controlling the tolerance of shaft and bearing housing. At present, many domestic manufacturers only control the tolerance, not roundness.
2. Bearing assembly method: because the bearing is a high-precision product, it is easy to damage the bearing channel and cause bearing damage if it is not assembled properly. The bearing shall be equipped with a special mold during assembly, and can not be knocked at will. When pressing the shaft, only the small ring can bear the force, and when pressing the large ring, only the large ring can bear the force. Air pressure or hydraulic pressure shall be used during assembly. The upper and lower molds shall be outside the horizontal state during press assembly. If there is any inclination, the plane bearing channel will be damaged due to stress, and the bearing will have a guide sound.
3. Prevention of foreign matters during assembly: When the bearing is installed on the rotor for dynamic balancing, it is easy to enter the iron filings generated during dynamic balancing into the bearing, so dynamic balancing shall be carried out before installing the bearing. For the convenience of assembly, some manufacturers apply some oil or grease in the bearing chamber for lubrication, but it is often difficult for operators to control the amount. If oil or grease is accumulated in the bearing chamber, it is easy to enter the plane bearing along the shaft when the bearing rotates. It is better not to apply oil or grease to the bearing chamber. If it is necessary to apply oil or grease, it is necessary to control the accumulation in the bearing chamber.
4. Prevention of paint rust: paint rust is often found in hermetically sealed motors. The sound of the motor is very good when it is assembled. However, after it is stored in the warehouse for some time, the abnormal noise of the motor becomes very large, and the bearing is seriously rusted when it is removed. Many manufacturers used to think that it was the problem of bearings. After our constant publicity, the motor factory has realized that the main problem is the insulation paint. This problem is mainly because the acidic substances volatilized from the insulating paint form corrosive substances at a certain temperature and humidity, which corrodes the plane bearing channel and causes bearing damage. At present, this problem can only be solved by selecting a good insulating paint and assembling it after drying and ventilation for a period of time.
