Arrangement Design of Spindle Bearing for FAG Precision Machine Tool

Adjacent Structure In order to make full use of the precision and rigidity of the FAG spindle bearing in the machine, it must be ensured that the adjacent structure of the bearing not only has a certain size and geometric accuracy, but also has sufficient rigidity and bearing capacity. Pay particular attention to the large axial loads that may occur. It is recommended to provide a rigid, dimensionally stable foundation in the direction of the machine bed mounting point. Shaft and seat hole tolerances The bearing fit is derived from ISO shaft and seat hole tolerances (ISO 286) and is associated with bearing bore tolerance dmp and bearing outer diameter tolerance Dmp (DIN 620). Reference axis and hole tolerance tables The recommended values ​​for shaft and housing hole tolerances apply to normal installation and operating conditions, see page 37, table.

  FAG radial bearings with cylindrical bore Radial shaft diameter tolerance 1) C/P 10. 2) C/P 10 10. Thrust Bearing Shaft Tolerance Rotational Condition Bearing Type Shaft Diameter Mobility Load Tolerance Band mm Inner Ring Bearing Point Load Ball Bearing, Roller Bearing All Sizes Inner Ring Easy to Move g6 (g5) Inner Ring is not Easy to Move, Angular Contact Ball Bearing and Belt Tapered roller bearings with adjustable inner ring h6 (j6) Inner ring subjected to cyclic load or inaccurate load direction Ball bearings 100 to 200 Low load 1) k6 (k5) General and heavy loads 2) m6 (m5) greater than 200 Low Load m6 (m5) General and Heavy Loads n6 (n5) Roller Bearings 60 to 200 Low Load k6 (k5) General Load m6 (m5) Heavy Load n6 (n5) 200 to 500 General Load m6 (m5) Weight Load, impact load p6 greater than 500 General load n6 (p6) Heavy load p6 load Bearing type Shaft diameter tolerance Band axial load Thrust deep groove ball bearings All sizes j6 Thrust cylindrical roller bearings with shaft ring h6 (j6) Thrust cylindrical roller Sub and cage assemblies.

  Housing bore tolerances FAG radial bearings 1) G7 Housings made of GG, if the bearing outside diameter D 250 mm and the outer ring and seat hole temperature difference 10K. 2) F7 Housing made of GG, if the bearing diameter D 250 mm and the temperature difference between the outer ring and the seat hole is 10 K. Thrust bearing Housings Tolerances Rotational condition Mobility Load condition Tolerance band Outer ring Bearing point load The outer ring is easy to move. The tolerance of non-split bearing housing is determined according to the required running accuracy. H7 (H6) 1) The outer ring is easy to move , Split housing H8 (H7) outer ring is not easy to move, non-split bearing 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 Ordinary running accuracy of the split bearing housing H7 (J7) The outer ring is easy to move the heat transferred from the shaft G72) The outer ring is subject to circumferential load or uncertain load direction Low load, the outer ring can not move 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 , The outer ring cannot move P7 (P6) Load Bearing type Operating tolerances Axial load Axial deep groove ball bearings Normal running accuracy E8 High running accuracy H6 Thrust cylindrical roller bearings with raceways – H7 (K7) Thrust cylindrical rollers And cage assemblies – H10.