With the progress and development of society, mechanization is widely used in production and life. As an indispensable part of machinery, bearings will be used more and more widely because they are used wherever there is rotation.

Bearings in machinery is mainly to support and reduce the role of friction, so the accuracy of bearings, noise, etc. are directly related to the use and life of machinery. But business people always often encounter some customers that use the best bearings or imported bearings and its efficiency is not high, which relates to the use of bearings and selection issues. Perhaps someone will say "bearing use and selection that is the user's business, I only care what the user wants what I sell". But as a qualified sales staff in addition to proficient in their own product knowledge, but also proficient in the use of products, that is, doctor-type sales, according to the user's supporting the performance of the product, the use of conditions to choose the best supporting bearings. This is currently the world's major companies popular specialized manufacturing and sales, this approach in the Humana Group since its implementation has also achieved good results.

Because of the wide range of bearing types, the following will mainly be the use and selection of the most widely used deep groove ball bearings for some analysis. We hope that people who know less about bearings can deepen their understanding of bearings.

I. Bearing selection

1、The choice of bearing type: The bearing type is generally chosen by the user's technical personnel according to the conditions of use of the supporting products and the bearing load. Business personnel mainly understand whether the actual load of the user is in line with the selected bearing, if the bearing can not meet the use requirements, the customer should be recommended as soon as possible to change the model, but unless special products in the selection of the model will generally not have any problems.

2, the choice of bearing clearance: users in the purchase of bearings will generally only inform in what model, grade, rarely will the bearing clearance requirements, business personnel must ask the bearing conditions of use, which bearing speed, temperature, with tolerance are directly related to the choice of bearing clearance. Generally in 3500 rpm below the speed of most of the motor using CM clearance, such as high temperature high speed motor is required to use relatively large clearance. Bearing clearance in the assembly will be because of the inner hole of the rise and the outer circle of the narrowing and lead to reduce, clearance of the reduction = interference amount × 60% (bearing chamber is aluminum except). For example, bearing clearance before assembly is 0.01mm, assembly interference is 0.01mm, then bearing clearance after assembly is 0.004mm. in theory bearing in zero clearance when noise and life reach the best state, but in actual operation considering temperature rise and other issues, bearing clearance after assembly is 0.002mm-0.004mm better.

3, grease selection: grease selection is generally based on the bearing speed, temperature resistance, noise requirements and starting torque and other aspects of the choice, requiring business personnel to understand the performance of various grease.

4, the choice of bearing seal type: bearing lubrication can be divided into oil lubrication and grease lubrication. Oil-lubricated bearings are generally selected form bearings, grease lubrication bearings are generally selected dust cover or rubber seal seal. Dustproof cover is suitable for high temperature or the use of good environmental parts, seals are divided into contact sealing and non-contact sealing, contact sealing dustproof performance is good but the starting torque is large, non-contact sealing starting torque is small, but the sealing performance is not contact good.

Renben bearings are currently specialized in automobile motor bearings, home appliance motor bearings, motorcycle bearings, health care motor bearings and other industries, so that the noise and life of the bearings can reach the best state.

II. Precautions to be taken when using bearings

1、Shaft and bearing room tolerance selection and control: The bearing should rotate flexibly without blocking feeling after pressing into the bearing. If there is obvious inflexible rotation, it means the size of the shaft is too big and the tolerance should be adjusted downward. If there is obvious "rustling" feeling after the bearing is pressed into the shaft, the tolerance of the shaft may be too large or the roundness of the shaft is not good. So in the control of the shaft and bearing room tolerance should also control the roundness, at present many domestic manufacturers only on the tolerance control, no control of roundness.

2. Bearing assembly method: Because bearings are high-precision products, improper assembly can easily cause damage to the bearing groove and lead to bearing damage. Bearings should have special molds during assembly, and cannot be knocked at will. Only small circles can be stressed when pressing into the shaft, and only large circles can be stressed when pressing large circles. When assembling, air pressure or hydraulic pressure is required, and the upper and lower die should be outside the horizontal state when press-fitting, if there is any tilt, it will lead to the bearing groove being damaged by the force, and the bearing will produce the guide ring.

3, assembly of foreign objects to prevent: bearing in the installation to the rotor to do dynamic balancing is easy to dynamic balancing when the iron chips into the bearing inside, so it is best to do dynamic balancing before loading bearings. There are some manufacturers in order to facilitate assembly, assembly in the bearing room coated with some oil or grease lubrication effect, but often the operator is difficult to control the amount of good, if the oil or grease in the bearing room to accumulate more, in the bearing rotation is easy to enter the bearing along the shaft inside. Bearing room is best not to apply oil or grease, such as must be coated to control not to have in the bearing room to stay.

4, paint rust prevention: paint rust characteristics are mostly in the sealed motor, the motor in the assembly sound is very good, but in the warehouse after some time, the motor noise becomes very large, remove the bearings have serious rust phenomenon. In the past, many manufacturers would think that it is the problem of bearings, after our continuous publicity, now the motor factory has realized that it is mainly the problem of insulating paint. The problem is mainly because the insulating paint volatile acid in a certain temperature, humidity, the formation of corrosive substances, the bearing groove corrosion caused by bearing damage. At present, the problem can only be solved by using good insulating paint and assembling after drying and ventilation for a period of time.

Bearing life is closely related to manufacturing, assembly and use, and must be done in each link to keep the bearing in the best operating condition, thus extending the bearing life.