Key technologies for bearing manufacturing
Modern simulation technology has developed rapidly with the widespread use of computers,The specific method of the technology is to input the load direction, size, lubrication mode, rotation speed and environmental parameters of the bearing under certain application conditions, and the main parameters of the bearing into the computer at the same time, through calculation, to understand the possible life of the bearing, and thus evaluate the bearing. Whether the design is useful. This test method can greatly shorten the test time, reduce the manpower and test funds, and can know the application effect before the bearing is not manufactured. It is a quick and worry-free test method. The research of bearing simulation test technology by SKF and NTN of foreign advanced bearing industry companies has reached advanced level.
Domestic and international development trends.
At present, there are four main bearing test methods at home and abroad: 1. friction and wear test, second, test bench test, third, test room (test field) simulation test, and fourth, actual working condition operation test. Foreign countries have used the above several test methods, but the application purpose is different. For example, to develop a brand new product, firstly, a friction and wear test must be performed. However, if there is not much change in the form of friction and wear, only the product size and load conditions change, only the bench, simulation or actual running test is needed. Foreign countries have very strict assessments of new products (such as car wheel bearings, etc.) in key parts, and must be tested in actual operation before they can be approved for use. Sweden SKF, Japan NTN recently researched bearing simulation test technology, can only replace bench, simulation or experiment, to shorten the time of product design, speed up the progress of product development, but there is still a gap from the actual operation. At present, China's bearing industry has carried out friction and wear tests, only one of Luoyang Bearing Research Institute; has carried out bearing bench test, including Luoyang Bearing Research Institute, Shanghai Axis Research Institute, Hangzhou Bearing Test Center and Wafangdian, Harbin, etc. Yujiaguo has bearing enterprises; Luoyang Bearing Research Institute, Hangzhou Bearing Test Center, Luozhou, Xenxi and other enterprises can be launched for simulation test. In order to carry out the actual test, the bearing manufacturer will only carry out the requirements when the supporting mainframe enterprise puts forward this aspect, such as the wheel bearing of the railway passenger wheel to the bearing and the car. In short, the domestic implementation of simulation and actual operation test is not extensive, and should further expand the scope of the host or the actual working conditions, and prepare sufficient software and hardware for the simulation test to mention the schedule as soon as possible.
Main research content and objectives
In order to carry out the simulation test, it is necessary to carry out bench or simulation tests on some typical types of typical products to find the functional relationship between life and load and working conditions, and then use this relationship to carry out bearing design and test work through computer. This is usually only a test for products that are extremely important. According to China's existing capabilities, the main goal for the next ten years is to simulate and test the railway vehicle bearings, automobile wheel bearings and high-speed grinding spindle bearings, and gradually have certain simulation test conditions. The research contents are as follows:
Rolling bearings fail due to the constant wear of the bearings during the movement. The grease (oil) and the lubrication method are different, which has different effects on reducing the friction and wear of the bearings. Therefore, lubrication technology has become an important part of bearing technology research. Some people refer to grease (oil) as the "fifth part of the bearing" (others are inner ring, outer ring, rolling element, cage).
The resistance to the rotation of the rolling bearing consists of rolling friction, sliding friction and lubricant friction. Rolling friction occurs when the rolling bodies roll on the raceway; the sliding friction occurs on the guide faces of the rolling bodies in the cage, on the rib guide faces of the cage and on the roller end faces and the ferrule ribs in the roller bearings. The friction of the lubricant consists of the internal friction of the lubricant at the contact and the agitation and extrusion of the lubricant. The total friction of a set of bearings, ie the sum of rolling friction, sliding friction and lubricant friction, is the resistance of the impedance bearing movement. The task of studying lubrication technology is to develop different greases (oils) and their lubrication methods to minimize bearing resistance and longest life.
Domestic and international development trends
Foreign advanced industrial countries have completely passed the bearing grease (oil), technology and production under common working conditions, and have formed a series of varieties and batch production capacity. The current main trend is to study the performance of grease in some special cases. For example, it is being studied to improve the vacuum stability, creepability and viscosity-temperature performance of perfluoroether grease for aerospace; and such as low-temperature grease, although it has good effects in application, its lubrication mechanism has not been well theoretical. set forth. Another example is the study of the use of gaseous lubricants at high temperatures (200-4000 C). The current research task of bearing lubrication in China is extremely important. If the funds permit, the following problems should be solved: First, improve the service life of the existing sealed bearing grease under normal temperature environment; Second, improve the vibration of low noise bearing grease Performance; Third, research and development of new varieties of bearing grease under common working conditions, to fill the domestic gap.