The introduction of bearing and ball working conditions

Rolling bearing is one of the important basic standard of mechanical industry. Rolling bearings by a professional bearing factory mass production, the user simply according to specific working conditions of the reasonable selection of bearing type and size, bearing capacity, calculation of the bearing and the bearing of composite structure design ( Bearing positioning, installation, adjustment, lubrication, sealing, etc. ) 。 Rolling bearing on rolling contact between components to withstand the load, compared with sliding bearing, roller bearing small friction resistance, high efficiency, easy starting, easy installation and maintenance, etc. Defect is poor impact resistance performance, high speed low service life, noise and vibration is larger when overloaded. The basic structure of the rolling bearings, inner ring and outer ring, rolling body 2 1 3 and cage 4 and so on four parts. Commonly used with the ball roller, cylindrical roller, needle, taper roller bearing inner and outer ring and rolling body, usually with the bearing steel ( GCr15, GCr15SiMn) Manufacturing, should reach 61 ~ 65 HRC hardness after heat treatment. Cage has a stamping and entity of two kinds of structure. Stamping maintains a generally made from low carbon steel plate stamping, it has a big gap between the roller and noise at work; Entity maintains a common copper alloy, aluminum alloy or phenolic resin polymer materials, such as good isolation and centering effect. When rolling body is cylindrical or needle, sometimes in order to reduce the bearing radial size, can save inner ring and outer ring or cage, the journal or bearing to have the effect of inner ring or outer ring. To meet the needs of the use of certain, some additional bearing with special structure or element, such as the outer ring snap ring, additional dust cover and so on. Just the working conditions of rolling bearing is very complex, under all kinds of high alternating stress. Single-row radial ball bearing, for example simple analysis. In every moment, only in the several ball bearing under the horizontal diameter under load, and role in these ball bearing load distribution is not uniform. Generally think that the distribution of forces acting on the ball of the F abide by the law of cosines, namely F = Qcos theta. Directly, therefore, is located in the Q force at the bottom of the ball bearing under maximum load, when high speed bearing, ball and ring raceway surface every point alternating load. Force changes from zero to maximum, and then by the biggest reduce to zero, weeks and reciprocating increase and decrease. As a result, the inner and outer ring rolling bearing and rolling body works under the contact stress of alternating, bearing parts of roller and ring raceway in theory a point ( Ball bearing) Or line ( Roller) Contact, but actually to withstand the load, due to the elastic deformation of the metal, make the stress concentration in a tiny surface, the maximum contact stress of up to 3000 - 5000Mpa。 In the process of operation, the ball except under loads, is due to centrifugal force caused by the load, the load increases with increase the rotational speed of bearing. Between roller and ring and retainer and the relative sliding, relative to the friction. Roller and ring face chemical erosion by water or impurities of lubricating oil. In addition, in all kinds of vehicles, rolling mill, mining machinery and all kinds of mechanical bearing, bearing parts also while working under complex torque or impact load and vibration effect: in some cases, the bearing parts still under the influence of high temperature and low temperature and high corrosive medium.