Common faults in stamping bearings
The failure phenomenon of stamping bearings generally shows two types. One is that the temperature of the bearing installation part is too high, and the other is that there is noise in the bearing operation.
1. Bearing temperature is too high
When the mechanism is running, the part where the bearing is installed is allowed to have a certain temperature. When the body of the mechanism is touched by hand, it should be normal to not feel hot, otherwise the bearing temperature is too high.
The reasons for the bearing temperature being too high are: the quality of the lubricating oil does not meet the requirements or deteriorates, the viscosity of the lubricating oil is too high; the assembly of the mechanism is too tight (the gap is insufficient); the bearing assembly is too tight; the bearing race rotates on the shaft or inside the casing; Large; bearing cage or stamping body fragmentation.
2. Bearing noise
The stamped bearing allows a slight running noise during operation. If the sound is too loud or there is abnormal noise or impact, the bearing is faulty.
The causes of noise generated by stamping bearings are more complicated. One is the wear of the inner and outer rings of the bearing. Due to this wear, the bearing and the housing, the bearing and the shaft are broken, resulting in the axis deviating from the correct position and generating an abnormal sound when the shaft is moving at a high speed. When the bearing is fatigued, the surface metal peeling off will also increase the radial clearance of the bearing to produce abnormal noise. In addition, insufficient bearing lubrication, dry friction, and bearing crushing can produce abnormal sounds. After the bearing wears loose, the cage is loose and damaged, and abnormal noise is also generated.
Correct use of stamped bearings
1. Bearing disassembly
The bearings should be cleaned before installation. When installing, use a special tool to press the auxiliary bearing straight and evenly. Do not hit with a hammer, especially for directly hitting the bearing. When the bearing race and the seat hole are loose, the seat hole or the replacement bearing should be repaired. Do not use the method of pitting or copper padding on the bearing mating surface. When the bearing is disassembled, use a suitable puller to pull the bearing out. Do not hit the bearing with a chisel or a hammer.
2. Lubrication of bearings
Lubricants commonly used in stamping bearings are lubricants and greases. When the peripheral speed of the shaft is less than 4-5m/s, or the parts of the car that cannot be lubricated with lubricating oil, they are lubricated with grease. The advantage of grease lubrication is that the sealing structure is simple, the grease is not easy to be lost, and the temperature is not affected much. The grease can be used for a long time.
There are two problems to be aware of when using grease. First, select the appropriate grade of grease according to the requirements of the car manual. For example, it is not advisable to use nano-based grease for automotive water pump bearings because of its poor water resistance. Second, the amount of grease to be added to the bearing should be appropriate. Generally, only 1/2-l/3 of the bearing cavity is filled. Excessive use is not only useless, but also increases the running resistance of the bearing to make it heat up. Special attention should be paid to the automobile wheel hub bearing. It is necessary to promote “empty hub lubrication”, that is, only apply a proper amount of grease on the bearing. Otherwise, it will not only waste and dissipate heat, but also cause the grease to overflow and may affect Braking performance.
Lubricating oil has the advantages of low frictional resistance and heat dissipation, and is mainly used for bearings with high speed and high working temperature. The grade of the lubricating oil should be selected according to the requirements of the automobile manual, and the vehicle maintenance cycle should be replaced in time. After the old oil is released, the mechanism should be cleaned and then new oil should be added. The fuel should be added to the specified marking line or flush with the filling port. (Depending on the specific structure and requirements of the car), it is not allowed to add more.
Stamping bearings are widely used mechanical basic parts and are widely used in various fields of national economy and national defense.
The history of invention of stamped bearings is very long. According to the archaeological relics found in Yongji County, Shanxi Province, China, as early as 221~207 BC (Qin Dynasty), there were bronze stamping bearings; according to the archaeological relics of Lake Nimi in Italy, AD 12~ In 41 years, bronze stamping bearings have also been produced. The birth of the modern bearing industry was the invention of the world's first grinding machine in 1883, and it has since entered the era of industrial production of steel balls. Stamping bearings have flourished along with the bicycle, automobile and other industries during the second industrial revolution. They have gradually become a highly professional industrial industry in the world, and they have a very important position and role in modern industry.
The importance of stamping bearings is mainly reflected in the following aspects:
(1) In the national economy - stamped bearings are called "industrial joints." As the basic industry and backbone industry of the machinery industry, the bearing industry's level of development often represents or restricts the development level of a country's machinery industry and other related industries. In Japan, people often refer to bearings as industrial food. The bearing industry is called "the core industry of the machinery industry" and "the basic industry to improve the national life". It is protected and supported by the Japanese government's revitalization policy. It is 14 specific. One of the industries of the machinery industry. In China, stamping bearings are one of the 11 categories of specific revitalized machinery products identified by the state, and 33 bearing companies are listed as specific revitalization industries. Among the 520 key enterprises newly identified in the country, the bearing industry is in possession of six. In the “Currently List of Industries, Products and Technologies Encouraged by the State”, the manufacture of car bearings, railway locomotives, precision bearings and high-speed bearings is included.
(2) In the national defense industry - stamping bearings are essential military supplies. Without bearings, missiles can't be lifted, planes can't go to heaven, warships can't go out to sea, tanks can't attack... Bearings are important or core parts in many military equipment; in war, bearing manufacturers are hostile countries. One of the targets of the key strikes; during the Cold War, bearing-specific equipment was one of the embargoed materials that Western countries imposed economic blockade on socialist countries. To date, many bearing products and technologies are still listed in the technical blockade by many military powers.
(3) In terms of technical status - bearing steel is the most demanding and most stringent steel grade in various alloy steels. It is recognized in the world that the level of smelting of bearing steel is a sign of the level of metallurgical technology in a country. In China, among the special steels such as stainless steel, high-speed steel, gear steel, valve steel, spring steel, etc., bearing steel is one of the few steel types that have to be issued production licenses so far. Stamping bearings are also an important application area for many new materials such as engineering ceramics and engineering plastics.