How to extend bearing life
作者:本站 来源:本站时间:2016/7/3 19:28:48
Cause of bearing failure are many, but often incorrect use, improper contamination, lubricant use, handling or damage during transportation and installation errors. Diagnose the cause of the failure is not difficult, because of bearing failure can be determined bearing traces.
Nature harsh working conditions will lead to failure of the bearing, but if you follow some simple rules, chance is bearing the normal operation can be improved. In the course of which the bearing, excessive neglect can lead to overheating of the bearing, it may also make the bearing can no longer be used, or even completely destroyed. But a damaged bearing, will leave clues to why it was damaged. Through some careful detective work, we can take action to avoid another failure of the bearing.
Cause of bearing failure are many, but often incorrect use, improper contamination, lubricant use, handling or damage during transportation and installation errors. Diagnose the cause of the failure is not difficult, because of bearing failure can be determined bearing traces.
1. Causes of bearing failure
About 40% of ball bearing failure is contaminated by the dust, dirt, debris and corrosion. Pollution is usually caused by improper use and poor use of the environment, it can also cause problems torque and noise. Bearing failure by the environment and pollution generated can be prevented, and by simple visual inspection can determine the cause of this type of failure.
By analyzing the failure may be that after already failed or will fail the bearings should be viewed in what areas. Clarify such as erosion and fatigue failure mechanism of a class of failure, helping to eliminate the root causes of the problem.
As long as a reasonable use and install, the bearing is easy to avoid erosion. Erosion is characterized in the bearing raceway ring raceway leave indentations produced by the impact load or incorrect installation. Erosion usually occurs when the load exceeds the material yield limit. If not properly installed so that a load across the bearing ring will produce erosion. Indentation on the bearing ring will produce noise, vibration, and additional torque.
A similar defect is when the bearing is not rotating ball in the mountains between the bearing ring and vibration generated oval indentation. This destruction is called low-load vibration eclipse. The damage in transport equipment and vibration still does not work when the device will have. In addition, the role of debris generated by low-load vibration eclipse as umbilical grain as would further damage the bearings. And erosion different erosion characteristics of low load vibration is usually due to fretting corrosion will damage generated in the lubricant pink.
Premature material fatigue failure is excessive after overloaded preload caused. If these conditions are unavoidable, it should be carefully calculated bearing life, to develop a maintenance plan.
2. The method to avoid bearing failure
The best way to solve the problem is to avoid bearing failure failure occurs. This can be in the selection process by considering the critical performance characteristics to achieve. These features include noise, starting and running torque, rigid, non-repetitive runout and radial and axial clearance.
Torque requirements mountain lubricants, cage, bearing the most quality circle (roundness and surface quality of the bent portion) and whether the sealing device or visor to decide. Viscosity of the lubricant must be selected carefully, because inappropriate lubricant will produce excessive torque, which is especially true in small bearings. In addition, the noise characteristics of different lubricants are not the same. For example, the noise generated by a large grease than some of the oil run. Therefore, in the selection of lubricants for different purposes.
In the bearing during rotation, if there is a random eccentric toe between the inner and outer rings, it will have a very similar movement of the cam non-repetitive runout ((NRR). Cage the size of the error and the bearing ring and ball eccentricity will cause NRR. runout and repeatability is different, NRR is no way to compensate.
In industry in general, depending on the application to select the different types and levels of precision bearings. For example, when the minimum requirements for runout, bearing non-repetitive runout should not exceed 0.3 m. Similarly, the only allowable minimum spindle runout, to ensure cutting accuracy. Therefore, the machine should be used in the application of non-repetitive runout smaller bearings.
In many industrial products, contamination is inevitable, so commonly used sealing device or visor to protect the bearing from dust or dirt so that erosion. However, due to the movement of the bearing inner ring, the bearing seal is impossible to achieve the perfect level, so the lubricant leakage and contamination is always a failure to solve the problem.
Once the contaminated bearing lubricants will deteriorate, operating noise also will be larger. If the bearing is overheating, it will get stuck. When contaminants between the balls and the bearing ring is, its role and abrasive particles between metal surfaces, as will the price bearing damage. Sealed and fend off dirt shield means is a method for controlling pollution.