Motor bearings are a common application scenario in bearing selection. The requirements for bearing selection may vary depending on the structure of the motor. Li Gong Bearing specializes in various types of motor bearings, agricultural machinery bearings, etc. Today, LIGZZ Mr. Li will share with you how to choose motor bearings.

Selection and use of motor bearings:

1、 The selection of Li Gong bearings

1. Selection of bearing model: The bearing model is generally selected by the user's technical personnel based on the usage conditions and load-bearing capacity of the supporting product. The business personnel mainly understand whether the actual load of the user matches the selected bearing. If Mr. Li's bearing does not meet the usage requirements, they should advise the customer to choose a different model as soon as possible. However, unless there are special products, there should generally be no problems in selecting the model.

2. Selection of bearing clearance: When purchasing Li Gong bearings, users usually only inform them of the model and grade, and rarely make requirements for the clearance of Koda Precision bearings. Business personnel must inquire about the usage conditions of the bearings, including the speed, temperature, and fit tolerance of the bearings, which are directly related to the selection of bearing clearance. Generally, motors with speeds below 3500 rpm use CM clearance, while high-temperature and high-speed motors require relatively larger clearance. The clearance of the bearing will decrease after assembly due to the increase in the inner hole and the decrease in the outer circle. The reduction in clearance is equal to the interference fit × 60% (except for bearing chambers made of aluminum). For example, if the clearance before bearing assembly is 0.01mm and the interference during assembly is 0.01mm, the clearance after bearing assembly is 0.004mm. In theory, bearings achieve optimal noise and lifespan at zero clearance, but in practical operation, considering issues such as temperature rise, it is better for bearings to have a clearance of 0.002mm to 0.004mm after assembly.

3. Selection of grease: The selection of grease is generally based on the speed, temperature resistance, noise requirements, and starting torque of the bearing, and requires business personnel to have a good understanding of the performance of various greases.

4. The selection of bearing sealing type: The lubrication of bearings can be divided into oil lubrication and grease lubrication. Oil lubricated bearings generally use formal bearings, while grease lubricated bearings generally use dust covers or rubber seals for sealing. Dust covers are suitable for areas with high temperatures or good usage environments. There are two types of seals: contact seals and non-contact seals. Contact seals have good dust prevention performance but large starting torque, while non-contact seals have small starting torque but not as good sealing performance as contact seals.

2、 Precautions for the use of Li Gong bearings

1. Selection and control of shaft and bearing housing tolerances: The bearing should rotate flexibly without any obstruction after being pressed into the bearing. If there is obvious inflexibility in rotation, it indicates that the size of the shaft is too large and the tolerance needs to be lowered. If there is a noticeable "sanding" feeling when the shaft is turned by hand after being pressed into the shaft, it may be due to the large tolerance of the shaft or poor roundness of the shaft. So when controlling the tolerances of the shaft and bearing housing, it is also necessary to control roundness. Currently, many domestic manufacturers only control the tolerances and do not control roundness. Li Gong's bearing quality inspection is comprehensive.

2. Assembly method of bearings: As bearings are high-precision products, improper assembly can easily damage the bearing channels, leading to bearing damage. When assembling bearings, there should be a dedicated mold that cannot be knocked randomly. When pressing the shaft, only the small ring can be subjected to force, and when pressing the large ring, only the large ring can be subjected to force. During assembly, it is required to use air pressure or hydraulic pressure. During pressing, the upper and lower molds should be in a horizontal state. If there is tilting, it will cause damage to the bearing groove due to force, resulting in bearing noise.

3. Prevention of foreign objects during assembly: When installing bearings on the rotor for dynamic balancing, it is easy for the iron filings generated during dynamic balancing to enter the interior of the bearings. Therefore, it is best to perform dynamic balancing before installing the bearings. Some manufacturers, for the convenience of assembly, apply some oil or grease to the bearing chamber during assembly to provide lubrication. However, it is often difficult for operators to control the amount well. If there is a large accumulation of oil or grease in the bearing chamber, it is easy to enter the bearing chamber along the shaft when the bearing rotates. It is best not to apply oil or grease to the bearing chamber. If it is necessary to apply it, it should be controlled not to accumulate in the bearing chamber.

4. Prevention of paint rust: The characteristic of paint rust is that it often occurs in sealed motors. The motor makes a good sound during assembly, but after being stored in the warehouse for some time, the motor's abnormal noise becomes very loud, and there is serious rust phenomenon when the bearings are removed. Many manufacturers used to think it was a problem with the bearings, but through our continuous promotion, now motor manufacturers have realized that the main issue is the insulation paint. The main reason for this problem is that the acidic substances evaporated from the insulation paint form corrosive substances at a certain temperature and humidity, which corrode the bearing channels and cause bearing damage. The current issue can only be solved by selecting good insulation paint and assembling it after drying and ventilation for a period of time.

The lifespan of bearings is closely related to manufacturing, assembly, and use, and must be done well at every stage in order to keep the bearings in the best operating state and extend their service life.

LIGZZ Li Gong Bearing provides you with the above content, hoping it can be helpful to you. Li Gong Bearing looks forward to cooperating with you! High speed motor bearings, choose Li Gong bearings.