When examining the advantages of chromium steel and stainless steel as Timken bearing materials, it is Timken Micro Bearing found that they do not only have the effect of rust prevention.
Chromium steel is a common micro bearing material. It is harder than stainless steel, so it has a longer service life. However, at higher temperatures, its performance is not very good.
At the high temperature of 120c, it will undergo huge deformation and reduce the load. The continuous high temperature of 150C can be tolerated, but the instantaneous temperature of 150C or higher will reduce the service life of imported bearings. Heat treatment can make the bearing bear the high temperature of 170C at an instant.
The lubrication purpose of Timken bearing is to reduce the internal Timken Micro Bearing friction and wear of the bearing and prevent burning and sticking. Its lubrication effect is as follows.
⑴. Reduce friction and wear.
The contact parts of the ferrule, rolling element and retainer constituting the micro bearing prevent metal contact and reduce friction and wear.
⑵. Extend fatigue life.
The rolling fatigue life of the bearing is prolonged when the rolling Timken Micro Bearing contact surface is well lubricated during rotation. On the contrary, if the oil viscosity is low and the lubricating oil film thickness is not good, it will be shortened.
⑶. Discharge friction heat and cooling
Circulating oil supply method can use oil to discharge the heat Timken Micro Bearing generated by friction or the heat transmitted from the outside for cooling. Prevent the bearing from overheating and the lubricating oil from aging.
It also has the effect of preventing foreign matters from invading the Timken Micro Bearing interior of the bearing, or preventing rust and corrosion.
The lubrication methods of Timken bearings are divided into grease lubrication and oil lubrication. In order to make the micro bearing function well, firstly, the lubrication method suitable for use conditions and purposes should be selected.
If only lubrication is considered, the lubricity of oil lubrication is dominant. However, grease lubrication has the advantage of simplifying the structure around the bearing. Compare the advantages and disadvantages of grease Timken Micro Bearing lubrication and oil lubrication.
The common stainless steel 440 used for micro bearings is hard and firm enough to load (20% less than Brass Steel), but it can resist rust and can withstand the instantaneous high temperature of 250C and the continuous high temperature of 300C.
We often mistakenly think that all stainless steel is non-magnetic, and 440 stainless steel is magnetic. It is not completely rustproof, but affected by salt, acid and alkali. 316 grade has good anti rust performance, no magnetism, but it is relatively soft, so it has less load. Because it is not firm, the accuracy of 316 bearing is not high and feels rough.
In order to give full play to INA Bearing and maintain its due performance for a long time, regular maintenance (regular inspection) must be done. Through proper regular inspection, it is very important to find faults early and prevent accidents before they happen, which is very important to improve productivity and economy.
Key factors affecting the service life of roller bearings for many rotating machinery products, their service life mostly depends on the service life of key parts of the product. “Maintenance free” bearings are not one-way bearings that will never be damaged or fail, but that will not be damaged within a certain period of time.
Here, the designers calculated the service life of the bearing ina. The service life of the bearing is greater than or equal to the overhaul cycle of the mechanical product. In this way, the bearing can be “maintenance free”. When the mechanical product is overhauled, it can be replaced with a new bearing without maintaining the used bearing.
When the ina bearing is Timken Micro Bearing disassembled for inspection, the appearance record shall be made by photography and other methods. In addition, confirm the amount of remaining lubricant and sample the lubricant before cleaning the bearing.
a. The cleaning of bearings is divided into rough cleaning and fine cleaning, and a metal grid can be placed at the bottom of the container.
b. During rough cleaning, use a brush to remove grease or adhesion in the oil. At this time, if the bearing is rotated in oil, pay attention to the damage to the rolling surface due to foreign matters.
c. During fine cleaning, rotate the bearing slowly in oil and carry out it carefully.
The commonly used cleaning agent is neutral water-free diesel oil or Timken Micro Bearing kerosene, and sometimes warm lye is used as needed. No matter what kind of cleaning agent you use, always filter it and keep it clean.
After cleaning, apply antirust oil or antirust grease on the roller bearing immediately.
2. Inspection and judgment
In order to judge whether the removed bearing can be reused, it is necessary to check its dimensional accuracy, rotation accuracy, internal clearance, mating surface, raceway surface, cage and sealing ring.
The inspection results can be judged by those who use inertial bearings or are proficient in bearings.
The judgment criteria vary Timken Micro Bearing according to mechanical properties, importance and inspection cycle. In case of the following damage, the roller bearing shall not be reused and must be replaced.
1) Fracture and defect of bearing parts.
2) Stripping of the rolling surface of the raceway surface.
During the operation of the mechanism, the part where the one-way bearing is installed is allowed to have a certain temperature. When touching the mechanism shell by hand, it should be normal to feel that it is not hot. Otherwise, it indicates that the temperature of ina bearing is too high.
The reasons for high bearing temperature include: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high;
The mechanism assembly is too tight (insufficient clearance); Roller bearing assembly is too tight; The bearing race rotates on the shaft or in the shell; Excessive load; Broken bearing cage or rolling element, etc.
The vibration system composed of stiffness, flexibility, mass and damping determined by the structural design parameters of one-way bearing will produce vibration suitable for its mechanics under operating conditions.
Vibration caused by deviation in manufacturing and processing. The smaller the deviation is, the smaller the vibration is.
The roundness, waviness and surface roughness of the steel ball surface are the factors that have a great impact on the vibration of INA Bearing parts, followed by the shape error and surface roughness of the inner ring and outer ring channels, and then the cleanliness and lubricant quality of roller bearing.
Operating conditions, such as installation conditions, rotating speed, axial load direction, quantity, etc.