1. characteristics of rolling bearings:
(1) the coefficient of friction is small and stable, starting is easy. In General, f=0.001-0.002 ball bearings, roller bearings, f=0.001-0.003, needle f=0.002, f=0.003 thrust ball bearing thrust roller bearing f=0.004.
(2) small axial dimensions.
(3) the small radial clearance, you can preload.
(4) the lubrication convenience, easy to maintain.
(5) some bearings can also accommodate circumferential and radial force, simple structure.
(6) disadvantage: poor resilience capacity, radial dimensions, high speeds, noise, short life.
2. the structure of rolling bearings and materials: is made of inner and outer, rolling elements and cage components of standard components. Ring and rolling element materials primarily chromium and high carbon steel for high strength, high hardness, such as GCr15, GCr15SiMn, etc. Also bowls useful ceramic ball, for high speed bearings. Cage with a soft sheet metal stamping, or copper, aluminum, zinc alloy or plastics.
3. the failure of rolling bearings: mainly caused by contact stress corrosion fatigue. Bearing life calculation according to pitting corrosion fatigue failure. BI-parting or seal porous FAG bearings, often wear failure occurs. Under impact loads or at low speed, bearing deformation failure may occur.
4. classification and selection of rolling bearings: mainly table on nine major categories. Among them, angular contact bearings and deep groove ball bearing can bear both radial and circumferential force, is more common. Self-aligning bearings can accommodate a small number of circumferential force. Circular roller and needle roller bearings do not withstand the circumferential force, not withstanding radial force of thrust bearing. In General, larger roller bearings bearing capacity, should be used in low-speed heavy and shock situations; ball bearings allowed higher speed, for high speed light load applications; misalignment or deformation of the shaft bearings with larger should be used.
5. accuracy of rolling bearings: precision rolling bearings are divided into: b, c, d, e and g grade. G to a normal level, the most widely used. B accuracy highest, price is the most expensive.
6. rolling bearings code: code used letters of the alphabet and numbers. Bearing D23024C says: D-D-level accuracy (first letter g may be omitted), 24-inner diameter d=24*5=120mm,0-diameter and width series, 23-type bearings (angular contact ball bearing).