Bearing clearance adjustment is bad ( 34% bearing fatigue)

Bearing in use process, many cases are due to fatigue failure, the reason is likely due to poor bearing clearance adjustment, according to statistics, 34% of bearing fatigue because clearance adjustment. Let's analysis about bearing clearance adjustment of related knowledge, hope to be of help. What is the bearing clearance? Bearing clearance is also known as bearing clearance. So-called bearing clearance, namely bearing in the bearing box mounted on shafts or not, will it a fixed housing, then bearing clearance is not a fixed one party do radial or axial movement of the mobile. According to the moving direction, can be divided into radial clearance and axial clearance. Clearance (in the operation of As the work clearance) About the size of the bearing fatigue life of rolling, temperature, noise, vibration etc. Bearing for cylindrical hole: the radial clearance after its installation size tolerance of hole and shaft are chosen by the shell. The greater the amount of interference between them, after the installation of the radial clearance. Therefore, the correct choice to match the bearing of the shaft and the hole tolerance is very important. For cone bearing: the interference is like cylindrical hole of bearing inner hole, determined by the tolerance of the selected axis, and depends on the bearing on the conical journal or conical set into the distance on the set of length. Standard bearing clearance is not stipulated by the state to see usage: still quite complicated problems, briefly as follows: the principle of choosing A, clearance: 1, using A tight fit, both inside and outside temperature difference is bigger, need to reduce the friction torque and deep groove ball bearings under high axial load or need improve heart function, appropriate USES large clearance group. 2, when the rotation accuracy is higher, or need to strictly limit the axial displacement, appropriate USES small clearance group. B, factors related to the clearance: 1, with the bearing inner ring and the shaft. 2, with the bearing outer ring and shell holes. 3, the influence of the temperature. Note: the radial clearance reduction amount of the real effective interference with mating parts, and the size of the suitable diameter of axle, the wall thickness of shell. Bearing radial clearance measurement: ( 1) Check with finger of lead wire rolling bearing axial clearance, the occasion of this kind of method is applied to the shaft end exposed. When the shaft end sealing or for other reasons and can't check with your fingers, can check flexible rotation axis. （ 2) With feeler check, operation method and the same with the method of the plug to check the radial clearance, axial clearance but should be c = 1 / ( 2 sin your problems in the Q type c axial clearance, mm; E one feeler thickness, mm; a - - Bearing cone Angle, °) 。 （ 3) With dial gauge inspection, with jack up shaft axis in two extreme position, the difference of the dial gauge readings for bearing axial clearance. But on the levers are not too large, otherwise shell elastic deformation occurs, even if the deformation is small, also affect the accuracy of the measured axial clearance. How to adjust axial clearance? 1, the use of installed on the bearing shell of the nut of the gland of pressure in the bearing outer ring. 2, to add and subtract the shim thickness between bearing cover and stand. Gear adjustment of the position: gear position adjustment: due to the installation of the gear and shaft form, one end is mostly used for the shoulder or steps, at the other end of the positioning mainly USES the spacer, so the position of the gear only by the length of the spacer and subtract degrees to adjust.