Motor manufacturers reminded that the bearing system is a very critical quality operation element of the motor products, and the bearing fever is often the main reason for the damage of the bearing system.
Fever of the bearing will lead to the degradation of the bearing grease, resulting in deformation of the bearing surface, inner ring and cage, etc., the lighter is the bearing noise problem, and the severer causes the bearing system to be ablated and the entire three-phase asynchronous motor is scrapped.
For ordinary three-phase asynchronous motors, there are relatively few problems with the bearing system. The manufacturers only need to carry out regular maintenance and adjustment according to the maintenance requirements of the motor, and for the special three-phase asynchronous motors for variable frequency use, as well as high-power motors and high-voltage There are relatively many problems with motors and bearing systems, and they can be tricky to handle.
The following are the common reasons for the fever of the three-phase asynchronous motor bearings sorted out by the motor manufacturers.
Matching of motor operating conditions.Regarding this issue, we have detailed explanations and joints in the special article on motor bearings. Especially for bearings of different series, the satisfaction of the normal clearance of the bearings depends on the dimensional tolerances of related parts, such as deep grooves. The working clearance of ball bearings is best controlled to zero clearance or negative clearance with a slight preload state, while the working clearance of cylindrical roller bearings should be positive clearance, even if it is small, it is necessary. The content of this aspect will not be repeated here.However, in practical applications, there are often unsuitable environments for the bearings for some reasons, or the unsuitability of the clearance caused by the interference, and there are also problems with the bearing running circle caused by the excessive common clearance. This city leads to the motor The bearing system collapsed in a short time.
Bearing ablation caused by galvanic corrosion.This problem is the shaft current problem that we originally talked about. The necessary conditions for generating shaft current are shaft voltage and closed circuit. For motors used under variable frequency conditions, as well as high-power and high-voltage motors, different levels of shaft voltage occur in cities. When the shaft voltage that the insulating function of the lubricant cannot withstand is generated, the larger shaft current will form a closed loop through the bearing and cause ablation problems to the bearing system components. The initial stage of ablation is expressed as bearing noise and accompanied by Fever, in a short period of time, the bearing system will be seriously hindered due to damage to the bearing components and fever.
In view of the above problems, the motor manufacturer has an independent optimization plan to optimize the design of the bearing system according to the customer's utilization, and recycle the genuine brand bearings at home to ensure that the three-phase asynchronous motor can run smoothly.
