Why use motor bearing? How to identify bearing - bearing knowledge

Motor bearings commonly used there are three main types: rolling bearing, sliding bearing and oil bearing, rotating support motor rotating components. Micro or small motor generally choose oil bearing, less accessories, maintenance free, to simplify the structure; Sliding bearing is mainly used in large motor, suitable for the occasion of overloading and impact resistance; Rolling bearings used most widely, the following Ms. And discuss the topic is aimed at this kind of bearing. How to identify the bearing rolling bearing code consists of pre codes, codes of basic and suffix code, front code by letters, meaning for the complete set of bearing branch; Basic code said bearing type and size of main feature; The suffix code said bearing accuracy and the characteristics of the material. Rear bearing codes and their meanings commonly used low internal structure symbol meaning the sample B - — The contact Angle of 40 ° C - angular contact ball bearing — Contact Angle is 15 ° angular contact ball bearing AC - — Contact Angle of 25 ° angular contact ball bearing E - — Reinforcement design low seal dustproof and external shape change symbol and meaning example code meaning symbol meaning N bearing outer ring has anti-rotation slot ( 2) RZ non-contact seal NR bearing outer ring has locking slot and stop ring bearing ( 2) Z dust cover sealed bearing ( 2) RS contact seal bearing ( 2) LS contact seal bearing ( Inner ring without the threaded) Low to keep the code symbol meaning of frame structure, material symbol meaning F steel cage class entity, the figures show that the different material after the J steel plate stamping cage, cage Q bronze entity Numbers represent different material after the V full M brass entity roller cage E phosphating cage T phenolic laminated tube distribution entities cage D carbonitriding cage TN engineering plastic mold injection maintains a low tolerance grade code P0 - — Dimensional accuracy level for P0 P6 - — Dimensional accuracy level for P6 P5 - — Dimensional accuracy for P4, P5 class - — Dimensional accuracy for P4 level P2 - — Dimensional accuracy for P2 level since level 0, in turn, improve the precision of rolling bearing. Low clearance code symbol meaning/C1 radial clearance for 1 group/C2 radial clearance of 2 - — Radial clearance is zero, namely ordinary clearance/C3 radial clearance for the 3 groups/C4 radial clearance group/C5 radial clearance for 4 to 5 groups/CM for motor bearing clearance low vibration level code Z - — Bearing vibration acceleration level extremum categories, from low to high as follows: Z3 and Z4 of Z1, Z2, V - — Bearing vibration velocity magnitude extreme value categories, from low to high as follows: V1, V2, V3 and V4 configuration code symbol meaning DB installed back to back in pairs, example: 7210 c/DB DF face-to-face installed in pairs, example: 32205 / DF DT series installed in pairs, example: 7210 c/DT bearing seal structure 2 z - — With dust cover bearing used in pollution is not serious and there's no water, steam and other dangerous contact bearings bearing configuration. Dust cover is also used in the speed or operating temperature considerations, it is very important to reduce friction applications. 2RZ— — Non-contact seal bearing are often used to pollution is not very serious, application and dust cover similar, slightly better than dust cover sealing effect. 2RS— — With the contact seal ( Referred to as the seals) Bearings are often used to secondary pollution and inevitable, such as water or water splash, or require no maintenance of long-term service life of bearing in the configuration. About the motor bearing clearance's radial bearing ( The axial) Clearance is when no bearing load function, relative another ring, a ring from a radial ( The axial) Limit position to move to the opposite extreme position of the radial ( The axial) Distance. In reality because of the ring shape error and the inconsistency of roller, it should be adopted in different direction of the ring and ring and different relative position of the radial roller ( The axial) Mean value of displacement. Low clearance is an important technological parameters of the bearing, it directly affects the distribution of load bearing, vibration, noise, friction, temperature rise, the service life of the running accuracy and mechanical and other technical performance. 一) Clearance is too large, will cause the bearing load decreases, and the contact stress increases, thus shortening the service life. Excessive clearance will cause the bearing running accuracy drop, vibration and noise. b） Clearance is too small, may appear in the actual operation negative clearance ( Interference) , increasing caused by friction heat and temperature increase, thus make less effective clearance or interference is bigger, so a vicious circle will cause bearing lock.