Whether the rolling bearing is good in grease or oil

Rolling bearings have both rolling and sliding friction. Sliding friction is caused by the deviation of the rolling bearing on the surface curve and the deformation of the bearing under load. For example, between the rolling element and the ring, since the ball and the ring are not absolutely rigid bodies, their contact areas always have elastic deformation, theoretically point contact or line contact, but in fact, the working conditions under load always become surface contact. Therefore, contact points having different diameters have different linear velocities to generate sliding friction. Sliding friction is also caused between the rolling bodies and the retainers as well as the retainer and the inner and outer rings for a variety of different reasons. The sliding friction increases with the increase of speed and load. In order to reduce friction, wear, reduce temperature and noise, prevent the rust of the bearing components, properly select the lubricant and use reasonable lubrication method, properly control the amount of lubricant. It is an important issue to improve bearing life.
    1. The basis of oil or grease for rolling bearings:
    The advantages of rolling bearings using lubricating oil lubrication are:
    1) Under certain operating specifications, the starting torque and friction loss of lubricating oil is significantly smaller than that of lubricating grease.
    2) Since the lubricating oil takes away heat in the circulation to cool, the bearing can be brought to a relatively high rotational speed.
    3) It can guarantee a relatively high operating temperature.
    4) When changing the grease, the relevant connecting parts must be disassembled, and when it is lubricated with oil, there is no such trouble.
    5) When the bearing in the reduction gearbox is lubricated with lubricating oil, it is suitable because the oil simultaneously achieves the purpose of lubricating the gear and the bearing at the same time in a splashing manner.
    6) In the bearing, the grease is gradually contaminated by the products worn by the product, the abrasive, the product penetrated from the outside through the sealing device and the product which is aging by itself. If not replaced in time, the bearing will accelerate the wear and tear, and when the liquid lubricant is applied, Filtered to keep it running.
    Advantages of grease lubrication for rolling bearings:
    1) Individual bearing points must be refueled by hand. If the grease is used, it will save trouble and avoid accidents caused by lack of oil.
    2) The grease itself has a sealing effect, which allows the use of a mechanism with a low degree of sealing to achieve a simplified design.
    3) Experience has shown that lithium grease lubrication has a lower temperature rise and longer bearing life than a drop method in a certain speed range (n<20000r/min or dn<20000mm.r/min).
    2. Theoretical basis of rolling bearing lubrication: The lubrication mechanism of rolling bearings belongs to the theory of dynamic fluid dynamic lubrication.
    3, rolling bearing failure type and lubrication relationship: most of the failure is due to assembly problems, poor sealing and damage. A small number of failures are caused by wear, gluing, corrosion and overheating due to lack or excess of lubricant or quality failure.
    4. Basic characteristics of grease and general criteria for selecting grease:
    When selecting grease, it is necessary to select the grease that is compatible with the conditions of use (temperature, speed, load, environment, etc.), which are related to the basic characteristics of the grease, and the basic characteristics of the grease depend on the thickener and base oil. kind of.

For more information and purchase please visit: https://www.supplyforever.com

Characteristics of powder metallurgy oil bearing

Powder metallurgy oil-containing bearings are generally manufactured by using raw material powders through pressing, sintering, shaping, and oil immersion processes. Most of today's machines are highly automated. The daily output is relatively large, and most of the products can be formed at one time, so the larger the batch, the better the production. Moreover, if the number of molds used now is less, it may be hundreds of thousands, and if it is more, it may be more than one million. However, the cost of the mold is relatively high, so if the batch size is small, it is not easy to do, and the time for replacing the mold is long.
     Powder metallurgy oil-impregnated bearings are generally formed at one time and are basically not machined. The cost is lighter than machining, the material waste is less, and the price is therefore cheaper. It is also in line with the current national policy of promoting energy conservation, so it is considered to be a technology that will not fall behind.
     The powder metallurgy oil-impregnated bearing has been filled with lubricating oil by vacuum impregnation in the base body, and the lubricating oil will seep out to the running surface due to temperature rise and pumping during operation, so it can be used without additional lubricating oil. The occasion.

For more information and purchase please visit: https://www.supplyforever.com