Microns about bearing life, how clearance is the most suitable knowledge - bearing

01 what bearing clearance so-called bearing clearance, namely not installed in the shaft bearing or bearing box, to fix them one housing, then the party has not been fixed do radial or axial movement of the mobile. ▼ bearing series of knowledge: clearance according to the direction of movement, can be divided into radial clearance and axial clearance. Radial clearance is: in the absence of load when a ring fixed, another ring relative to the fixed ring along the radial direction from one extreme to another extreme location of the mobile. The axial clearance is: in the absence of load when a ring fixed, another ring relative to the fixed ring along the axial position from one extreme to another extreme position of the mobile. Bearing clearance code: C0: standard clearance code, this code usually omitted in the bearing type is not marked C2: clearance slightly smaller than the standard clearance C3: clearance slightly larger than the standard clearance C4: than C3 clearance C5: slightly larger than the C4 slightly larger clearance ▼ rolling bearing radial clearance of national standard (note: junior partner with bearing type and inner diameter size and clearance level, corresponding to the corresponding standard form to query the bearing clearance. 02 classification: bearing clearance is adjustable or not clearance adjustment method is determined by the type of bearing, generally can be divided into clearance is not adjustable bearings and adjustable bearing. ► Clearance is not adjustable bearing clearance is not adjustable bearing is bearing factory, bearing clearance is sure. Include: deep groove ball bearing, self-aligning bearings, cylindrical bearings. For an adjustable bearing clearance, industry have corresponding standard ( The clearance of the five level) , can also be customized special clearance range. When the shaft and bearing seat size is known, the corresponding cooperate will determine the amount of inner and outer ring, will not be changed after installation of the clearance. Because at the design stage with quantity is a scope, the final clearance is also a range, the clearance of the request the precision is not applicable. ► Clearance adjustable bearing clearance adjustable bearing means can move the relative axial bearing raceway position to obtain the required clearance. Include: tapered bearings, angular contact ball bearings, as well as part of the thrust bearing. Adjustable bearing can well adapt to the accuracy requirement. Through changing the relative axial location of raceway, can get a certain clearance value. When moving the position of the inner ring, can be roughly be positive and negative two clearance. 03 selection and bearing lubrication bearing clearance by the same token, the lubrication grease too much or too little can lead to bearing temperature changes, causing damage to the bearings; Likewise, the bearing clearance is too large or too small, the working life of the bearing and the whole stability of the equipment operation will be reduced. From theoretical clearance minus the bearing installed on the shaft or shell because of the interference fit within the ring of the expansion or contraction after the clearance is called 'installation clearance'. Add and subtract in installation clearance because the size of the bearing internal temperature changes the amount of clearance is called 'effective clearance'. Bearing installed on the machine of clearance when placed under certain load, the effective clearance and bearing load produced by the elastic deformation after the clearance is called 'work clearance'. ▼ bearing clearance measurement when work clearance for micro negative, the bearing fatigue life expectancy. But with the increase of negative clearance a significant reduction in the fatigue life at the same time. Therefore, choosing the bearing clearance, general work clearance is zero or slightly as advisable. In addition, it is necessary to improve the bearing rigidity or reduce noise, further negative clearance to work; Working in the intense, bearing temperature clearance should further take positive. To achieve the ideal bearing life, must have the appropriate clearance, clearance (= the clearance value design The factory clearance) — Inner ring with the clearance reduction - Caused by outer ring fit clearance reduction + ( Or - ) The clearance reduction (because of the difference in temperature Or increase) Selection of specific clearance according to the installation of equipment technical standards.