In order to make full use of the accuracy and rigidity of the spindle bearing in the machine, the adjacent structure must ensure that the adjacent structure of the bearing not only has a certain size and geometric accuracy, but also has sufficient rigidity and load-bearing capacity. Pay special attention to the large axial loads that may occur. It is recommended to provide a rigid and dimensionally stable foundation in the direction of the installation point of the machine bed. Shaft and housing bore tolerance The bearing fit is derived from the ISO shaft and housing bore tolerance (ISO 286), which is related to the bearing bore tolerance dmp and the bearing outer diameter tolerance Dmp (DIN 620). Refer to the shaft and hole tolerance table. The recommended values u200bu200bfor shaft and seat hole tolerances apply to normal installation and operating conditions, see table on page 37. The shaft diameter tolerance of radial bearings with cylindrical bore 1) C/P 10. 2) C/P 10. Thrust bearing shaft tolerance, rotation condition, bearing type, shaft diameter, mobility, load tolerance zone mm, inner ring bearing point load, ball bearing, roller bearing, all sizes, inner ring is easy to move g6 (g5) inner ring is not easy to move, angular contact ball bearing and belt Adjustable inner ring tapered roller bearing h6 (j6) The inner ring is subjected to cyclic load or inaccurate load direction. Ball bearings 100 to 200 Low load 1) k6 (k5) general load and heavy load 2) m6 (m5) greater than 200 low load m6 (m5) general load and heavy load n6 (n5) roller bearing 60 to 200 low load k6 (k5) general load m6 (m5) heavy load n6 (n5) 200 to 500 general load m6 (m5) heavy Load, impact load p6 is greater than 500 general load n6 (p6) heavy load p6 load bearing type shaft diameter tolerance with axial load thrust deep groove ball bearing all dimensions j6 thrust cylindrical roller bearing with shaft ring h6 (j6) thrust cylindrical roller Sub and cage assembly. Bearing housing bore tolerance for radial bearings 1) G7 is a housing made of GG, if the outer diameter of the bearing is D 250 mm and the temperature difference between the outer ring and the housing bore is 10 K. 2) F7 adopts a bearing seat made of GG, if the outer diameter of the bearing is D 250 mm and the temperature difference between the outer ring and the seat hole is 10 K. Thrust bearing housing tolerances, rotation conditions, movable load conditions, tolerance zone, outer ring bearing point load, outer ring is easy to move, non-split bearing housing tolerance level is determined according to the required operating accuracy H7 (H6) 1) outer ring is easy to move , Split housing H8 (H7) outer ring is not easy to move, non-split housing requires high running accuracy H6 (J6) outer ring is not easy to move, angular contact ball bearings and tapered roller bearings with adjustable outer ring , Split bearing housing, ordinary running accuracy H7 (J7) Outer ring is easy to move, heat is transferred from the shaft G72) Outer ring bears circumferential load or low load with uncertain load direction, outer ring cannot be moved High running accuracy select K6, M6, N6 And P6K7 (K6) medium load, impact load, outer ring cannot move M7 (M6) heavy load, impact load (C/P 6), outer ring cannot move N7 (N6) heavy load, severe impact, thin-walled bearing seat , The outer ring can not move P7 (P6) load bearing type working condition tolerance with axial load thrust deep groove ball bearing ordinary running accuracy E8 high running accuracy H6 thrust cylindrical roller bearing with seat ring H7 (K7) thrust cylindrical roller and Cage assembly H10.