The lubrication purpose of Timken bearing is to reduce the internal friction and wear of Timken bearing and prevent burning and sticking. Its lubrication effect is as follows.
1. Reduce friction and wear.
The contact parts of the ferrule, body and retainer of Timken bearing prevent metal contact and reduce friction and wear.
2. Prolong fatigue life.
The fatigue life of Timken bearing is prolonged when the contact Lubrication Purpose 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.
3. Discharge friction heat and cooling
Circulating oil supply method can use oil to discharge the heat Lubrication Purpose generated by friction or the heat transmitted from the outside for cooling. Prevent Timken bearing from overheating and lubricating oil from aging.
The lubrication methods of Timken bearings are divided into grease lubrication and oil lubrication. In order to make Timken bearings function well, first of all, choose the lubrication method suitable for the service conditions and purposes. If only lubrication is considered, the lubricity of oil lubrication is dominant.
The advantages of using lubricating oil for rolling fag bearings are:
1) Under certain operating Lubrication Purpose specifications, the starting torque and friction loss of lubricating oil are significantly smaller than that of grease lubrication.
2) As the lubricating oil takes away heat in the circulation and plays a cooling role, it can make the fag Lubrication Purpose bearing reach a relatively high rotation speed.
3) It can ensure relatively high service temperature.
4) When changing grease, relevant connecting parts must be Lubrication Purpose disassembled. When lubricating with oil, there is no such trouble.
5) When the fag bearing in the reduction gearbox is lubricated with lubricating oil, it is very suitable, because the oil can Lubrication Purpose simultaneously lubricate the gear and fag bearing in a splash way.
6) In fag bearings, the lubricating grease is gradually contaminated by the products of product wear, abrasives, products penetrating through the sealing device from the outside and aging itself.
If it is not replaced in time, it will cause accelerated wear of fag Lubrication Purpose bearings. When liquid lubricant is applied, it can be filtered to ensure its normal operation.
Advantages of grease lubrication for rolling fag bearings:
1) Individual fag bearing points must be refueled frequently by Lubrication Purpose hand. If the grease is changed, it will not only save trouble, but also avoid accidents caused by lack of oil.
2) The grease itself has a sealing effect, which allows the Lubrication Purpose mechanism with low sealing degree to be used to simplify the design.
3) Experience has proved that in a certain speed range (n < 20000 R / min or DN < 20000 mm. R / min), lubrication with lithium grease has lower temperature rise and longer service life of fag bearing than oil dropping method.
2. Theoretical basis of rolling fag bearing lubrication: the lubrication mechanism of rolling fag bearing belongs to the theory of elastic fluid hydrodynamic lubrication.
3. Relationship between failure types and lubrication of rolling fag bearings: most failure causes are damage caused by faulty assembly and poor sealing. A few failures are caused by wear, gluing, corrosion and overheating caused by lack or excess of lubricant or unqualified quality.
4. Basic characteristics of lubricating grease and general criteria for selecting lubricating grease:
When selecting lubricating grease, it is necessary to select the lubricating grease suitable for the service conditions (temperature, speed, load and environment, etc.), which are related to the basic characteristics of lubricating grease, and the basic characteristics of lubricating grease depend on the type of thickener and base oil.
Sliding friction is caused by the deviation of rolling fag bearing on the surface curve and the deformation of fag bearing under load. For example, between the rolling element and the ring, because the ball and the ring are not absolute rigid bodies, their contact area will always produce elastic deformation.
In theory, it is point contact or line contact, but in fact, it will always become surface contact under load working conditions. Therefore, the contact points with different diameters have different linear velocities, resulting in sliding friction.
Similarly, due to various reasons, sliding friction will also occur between the rolling element and the retainer, as well as between the retainer and the inner and outer rings. The sliding friction increases with the increase of speed and load.
In order to reduce friction, wear, reduce temperature and noise, prevent the parts of fag bearing from rusting, correctly select lubricants and adopt reasonable lubrication methods, and appropriately control the amount of lubricants are important topics to improve the service life of fag bearing.
The above is the comparison of the effect of grease lubrication and oil lubrication in rolling fag bearings. I hope you can have some experience after it appears.