Failure form of rolling bearing
Failure Form of Rolling Bearing
2022年3月17日
Factors affecting bearing life and its control
Factors Affecting Bearing Life and Its Control
2022年3月18日

Monitoring of Working Condition of Rolling Bearing

Monitoring rolling bearing with magnetic plug method,Monitoring of Working Condition of Rolling Bearing

1. Requirements for monitoring rolling bearing with magnetic plug

(1) The magnetic plug is only suitable for monitoring the key main bearings lubricated with oil and returned through special pipelines.

(2) The magnetic plug shall be installed near the monitored main bearing as far as possible, on the main channel of oil return, and there is no barrier of filter screen, oil pump and other hydraulic parts in the middle.

(3) In order to improve the monitoring efficiency, a rotary oil reservoir with oil return inlet and outlet can be made. The oil reservoir shall be made into an inverted conical platform, and the magnetic plug shall be installed at the bottom of the oil reservoir. The oil inlet of the oil reservoir shall be inclined at a certain angle so that the lubricating oil can enter it from the tangential direction. 

The abrasive debris in the raceway presents the form of roughly circular surface fragmentation; The roller wear debris of roller bearing usually presents a curled rectangular form with a length equal to 2 ~ 3 times the width; The abrasive debris in the raceway generally presents an irregular rectangle.

This is conducive to the separation of wear particles from the rotating lubricating oil, precipitate at the bottom, enter the magnetic plug through the small hole and adsorb on the magnetic steel end.

2. Morphological characteristics of wear particles under normal conditions

During the running in period and normal operation period of rolling bearing, the size of abrasive debris generated is generally 0.01 ~ 0.015mm, and mixed with some metal powder. The number of abrasive debris produced by the new bearing during the running in period is more than that during the normal operation period.

 After entering the normal operation period, the number of abrasive debris and metal powder will be significantly reduced. Under the microscope, the abrasive debris presents a fine and short shape with irregular section.

3. Morphological characteristics of fault wear particles

The main failure mode of rolling bearing is fatigue pitting. The size of abrasive debris formed by rolling fatigue and spalling is generally 0.025 ~ 0.05mm. Sometimes there are larger pieces mixed with some metal powder. The steel ball abrasive debris of ball bearing usually presents the form of roughly circular rose petals separated along the radial direction; 

The abrasive debris in the raceway presents the form of roughly circular surface fragmentation; The roller wear debris of roller bearing usually presents a curled rectangular form with a length equal to 2 ~ 3 times the width; The abrasive debris in the raceway generally presents an irregular rectangle.

Problems needing attention in monitoring rolling bearing by temperature measurement

By measuring the temperature rise of the bearing during operation, it is generally difficult to monitor the local damage such as fatigue peeling, crack or indentation of the rolling bearing, especially in the initial stage of the damage, it is almost impossible to find any problems. 

When the temperature of the bearing rises after long-term normal operation, the problems generally reflected are not only serious, but also develop rapidly, resulting in bearing damage and failure. At this time, intermittent monitoring often leads to missing supervision. If the temperature of the bearing exceeds 70 ~ 80 ℃ during monitoring, it shall be shut down immediately for inspection.Monitoring of Working Condition of Rolling Bearing

For newly installed or readjusted rolling bearings, the temperature rise can be monitored by temperature measurement within the specified time to judge the installation and adjustment quality of bearings, especially when the clearance is too tight. If problems are found and adjusted in time, it is conducive to prolong the service life of rolling bearings.Monitoring of Working Condition of Rolling Bearing

Monitoring of Working Condition of Rolling Bearing