The principle of choosing the bearing clearance

A, clearance choice principle: 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. Second, the 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. 1, the real effective interference quantity ( Inner ring) Should be followed: delta dy = 2/3 delta d - delta G * d for the nominal amount of interference, G * for surplus with pressing size. 2, the real effective interference quantity ( Outer ring) Should be followed: delta Dy = 2/3 delta D - delta G * D for the nominal amount of interference, G * for surplus with pressing size. 3, the heat generated by the internal temperature will result in bearing, which in turn caused the expansion of the shaft, bearing and bearing parts. Clearance can increase or decrease, depending on the shaft and bearing material, and the temperature between bearings and bearing parts tonsure. Three, the calculation formula of clearance: ( 1) : 1, with the influence of the bearing inner ring and steel solid shaft: delta j = delta dy * d/h2, bearing inner ring and steel hollow shaft: delta j = delta dy * F ( d) F( d) =d/h*[ ( d / d1) 2 - 1] / ( ( d / d1) 2 - ( d / h) 2] 3, bearing outer ring and shell steel entity: delta A = delta Dy * H/D4, bearing outer ring and steel thin-walled shell: delta A = delta Dy * F ( D） F( D) = H / D * ( (