The key method of maintaining low noise embedded solid lubricating bearing

There are generally two methods for insulating bearings. One is to use insulated bearings, and the other is to use insulated bearing chambers.

Insulated bearings: Insulated bearings can be divided into inner ring coatings, outer ring coatings and rolling elements using ceramic materials. The inner ring coating and outer ring coating are made of ceramic materials coated on the bearing surface by plasma spraying. This coating can still maintain its unique insulation properties in a humid environment; while ceramic material rolling type insulated bearings, That is, the rolling elements are made of ceramic materials. Ceramic rolling element insulated bearings have excellent current resistance capabilities and can therefore be effectively insulated.

Insulated bearing chamber: Generally, a polytetrafluoroethylene film is pasted on the hole in the bearing chamber of the end cover to insulate the bearing and the end cover and cut off the channel of bearing current.

Straightener support roller bearings

Regardless of the form of insulation, it has its own advantages. When repairing motors, you should pay attention to the following four points when insulating bearings:

1. Selection and control of the tolerances of the shaft and bearing chamber of the insulated bearing: when the bearing is pressed into the bearing, it must maintain flexible rotation without any sense of blockage. If there is obvious rotational inflexibility, it means that the size of the bearing is too large, and the bearing tolerance needs to be lowered. If there is an obvious "sandy" feeling after the bearing is pressed into the shaft and turned by hand, it may be that the roundness of the shaft is not good or the tolerance of the shaft is too large.

2. Assembly method of insulated bearings: Because insulated bearings are high-precision products, improper assembly can easily cause damage to the bearing channels, resulting in damage to the bearings. The insulated bearing company reminds operators to use special molds when assembling bearings and not to knock them randomly. When pressing in the shaft, only a small circle can be stressed, and when a large circle is pressed, only the large circle can be stressed. Air pressure or hydraulic pressure must be used when assembling the bearing. The upper and lower dies need to be in a horizontal state during press installation. If there is an inclination, the bearing channel will be damaged due to stress, causing abnormal noise in the bearing.

3. Prevention of foreign matter in assembly: When the bearing is installed on the rotor for dynamic balancing, it is easy for the iron filings generated during dynamic balancing to enter the inside of the bearing, so it is best to perform dynamic balancing before installing the bearing. Do not apply oil or grease in the bearing chamber. If it must be applied, control it carefully and do not allow it to accumulate in the bearing chamber.

4. Prevention of paint rust: The characteristics of paint rust mostly occur in closed motors. The sound of the motor is normal during assembly, but after being placed in the warehouse for a period of time, the abnormal noise of the motor increases. If the bearing is removed, serious damage will occur. rust phenomenon. Many people will think it is a bearing problem but it is mainly a problem with the insulating paint. The main reason is that the acidic substances volatilized by the insulating paint are converted into corrosive substances under a certain temperature and humidity, corroding the bearing grooves and causing bearing damage. The best solution now is to use good insulating paint and ventilate it for a period of time before assembly.