High speed precision angular contact ball bearing is mainly used in high-speed rotation occasions with light load. It requires high precision, high speed, low temperature rise, low vibration and certain service life. It is often used as the support of high-speed motorized spindle. It is the key kit of high-speed motorized spindle of internal surface grinder.
1. Bearing accuracy index: Angular Contact Ball Bearing exceeding grade P4 accuracy in GB / 307.1-94
2. High speed performance index: DMN value 1.3 ~ 1.8x 106 / min
3. Service life (average): > 1500 H
The service life of high-speed precision angular contact ball bearing is closely related to installation. Angular Contact Ball Bearing The following matters should be paid attention to
1. The bearing shall be installed in a dust-free and clean room. Angular Contact Ball Bearing The bearing shall be carefully selected and matched. The spacer for the bearing shall be ground. On the premise of maintaining the equal height of the inner and outer spacer, the parallelism of the spacer shall be controlled below 1um;
2. The bearing shall be cleaned before installation. During cleaning, the inner ring slope shall be upward, and the hand shall be flexible without stagnation. After drying, Angular Contact Ball Bearing put the specified amount of grease. If it is oil mist lubrication, put a small amount of oil mist oil;
3. Special tools shall be used for bearing installation, Angular Contact Ball Bearing with uniform stress and no knocking;
4. The bearing shall be stored in a clean and ventilated manner without corrosive gas, and the relative humidity shall not exceed 65%. For long-term storage, it shall be regularly rustproof.
There are dozens of rolling bearings in cars, including almost all common bearing types, large and small. The crash and damage of rolling bearings are also common. Since rolling bearings are generally installed inside the mechanism, it is inconvenient to conduct visual inspection. Only a brief judgment can be made according to the fault phenomenon, and then disassembled for inspection.
The correct use of rolling bearing is a reliable guarantee to reduce bearing failure and prolong bearing life, including correct installation and reasonable lubrication.
The following describes the use requirements, common faults and damages of rolling bearings.
1. Disassembly and assembly of bearing
The bearing shall be cleaned before installation. During installation, the auxiliary bearing shall be pressed straight and evenly with special tools. Do not knock with a hand hammer. In particular, it is forbidden to knock directly on the bearing. When the fit between the bearing race and the seat hole is loose, the seat hole shall be repaired or the bearing shall be replaced.
Do not reluctantly use the method of pitting or padding copper skin on the bearing mating surface. When disassembling the bearing, use a suitable puller to pull out the bearing, and do not knock the bearing with a chisel, hammer, etc.
2. Bearing lubrication
There are two kinds of lubricants commonly used in rolling bearings: lubricating oil and grease. When the circumferential speed of the shaft is less than 4-5m / s, or the parts on the vehicle that cannot be lubricated with lubricating oil, grease shall be used for lubrication. The advantage of grease lubrication is that the sealing structure is simple, the grease is not easy to lose, and it is not affected by temperature. Adding grease once can be used for a long time.
Two problems should be paid attention to when using grease. One is to select the appropriate brand of grease according to the requirements of the automobile manual. For example, nano base grease should not be selected for automobile water pump bearing because of its poor water resistance. Second, the amount of lubricating grease added to the bearing should be appropriate.
Generally, it is appropriate to fill only 1 / 2-L / 3 of the bearing cavity. Too much is not only useless, but also increases the running resistance of the bearing and heats it up. Special attention should be paid to the automobile hub bearing. It is necessary to advocate “empty hub lubrication”, that is, only apply an appropriate layer of grease on the bearing. Otherwise, it will not only waste and poor heat dissipation, but also cause the grease to overflow due to heating, which may affect the braking performance.
The advantages of lubricating oil lubrication are low friction resistance and heat dissipation. It is mainly used for bearings with high speed and high working environment temperature. The brand of lubricating oil shall be selected according to the requirements of the vehicle manual, and shall be replaced in time after the vehicle maintenance cycle.
After discharging the old oil, the mechanism shall be cleaned before adding new oil. The oil shall be added to the specified marking line or flush with the oil filler (depending on the specific structure and requirements of the vehicle), and no more oil shall be added.