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Basic Requirements for Fault Analysis of INA Imported Bearings
Nov 28, 2018

The state of INA imported bearings is directly related to the running state of rotary equipment, and bearings are widely used in the equipment. Especially in large continuous production enterprises, it is widely used in important parts of large rotating equipment. Therefore, it is an important link to do well in maintenance and management of equipment to monitor and diagnose the condition of bearings in actual production. Through temporary practice and exploration, some practical skills of bearing fault diagnosis have been accumulated.

Vibration analysis is a practical method for condition monitoring and fault diagnosis of INA imported bearings. It is necessary to pay attention to the accuracy and authenticity of the collected signals. In practice, attention should be paid to the location of the measuring points and the acquisition method. In order to truly and accurately reflect the bearing vibration state. Therefore, in order to arrange measuring points nearest to the bearing, the free end of the motor usually has a rear fan cover, and the selection of measuring points in the fixed screw of the fan cover has a better monitoring effect. In addition, it is necessary to collect and analyze the vibration signals several times and compare them comprehensively. Talent leads to accurate conclusions.

INA imported bearings show a strong regularity in their use, which was found in temporary production condition monitoring. And the repeatability is very good. The vibration and noise of normal high-quality bearings are relatively small at the beginning of use, but the spectrum is scattered and the amplitude is small, which may be due to some defects in the manufacturing process, such as surface burrs.

Vibration and noise are maintained at a certain level after a period of exercise. The spectrum is very single, only one or two frequency doubles appear. The frequency spectrum above triple power frequency rarely appears. The bearing condition is very stable and it enters a stable working period.

The vibration and noise of the bearing begin to increase, and it enters the later stage of service after continuing operation. Sometimes abnormal sound occurs, but the vibration increases slowly. At this time, the bearing kurtosis value begins to suddenly reach a certain value. It is considered that the bearing is an initial failure at this time.

It is required that the bearing be closely monitored at this time. Pay close attention to its changes. Afterwards, the bearing kurtosis value began to decline rapidly and approached the normal value, while the vibration and noise began to increase significantly, and the increase began to accelerate. When the vibration exceeded the vibration specification (such as ISO2372 specification), the bearing kurtosis value also began to increase rapidly, when both exceeded the vibration specification, and the kurtosis value also exceeded the normal value (available kurtosis). Relative standard) It is considered that INA imported bearings have entered the late stage of failure production. It is necessary to timely repair equipment and replace bearings.

The larger the capacity of the equipment, the more time it takes for the bearings to show the late failure characteristics to appear serious failure (usually bearing damage such as axle holder, burns, sand frame splitting, raceway, bead wear, etc.) is less than one week. The faster the speed is, the shorter the interval time is. Therefore, in the actual bearing fault diagnosis, once the late fault characteristics are found, the bearing fault should be judged decisively and the maintenance should be arranged as soon as possible.

The assembly quality index of INA imported bearings, that is, the assembly accuracy requirements are mainly radial clearance and width. There is a certain functional relationship between the axial clearance and the radial clearance. Therefore, the axial clearance can be indirectly controlled by controlling the radial clearance.

For deep groove ball bearings, cylindrical roller bearings, self-aligning ball bearings and self-aligning roller bearings, radial clearance is mainly controlled.

For thrust ball bearings, thrust roller bearings and tapered roller bearings, height and width are mainly controlled.

For angular contact ball bearings, the contact angle is mainly controlled.

The basic requirement of rolling bearing assembly is that, on the premise of guaranteeing the assembly quality index, the assembly rate should be higher, generally more than 95%.