Research Progress on Monitoring and Separating Suspension Particles for Lubricating Oil

Lubricant failure or irrational lubrication is the root cause of industrial equipment failure. By monitoring the distribution of the suspended particles in lubricants, it is possible to discover hidden lubrication problems. After taking the lubricating oil samples of industrial equipment, the oil monitoring technology is used to analyze the particle size distribution and the type and content of the abrasive particles by electrical, magnetic, and optical monitoring techniques. It is necessary to separate the suspended particles in oils with impurities by some method to eliminate potential safety hazards and ensure the reuse efficiency of the lubricant. In this paper, the principles, advantages, and disadvantages of several important oil monitoring methods are described, and new developments in various methods are analyzed. Several typical methods for separation of the suspended particles in purified oils were introduced. The advantages and disadvantages of each process were summarized. The development direction of lubricant monitoring technology was pointed out, and guidance was provided for the separation and online monitoring of the suspended particles in lubricants. Finally, compared with similar review papers, this paper specifically figured out that ultrasonic separation method has the advantages of real time, high efficiency, and no pollution and has important application value for micron-scale particle separation of large precision machines.