Arrangement Design of FAG Precision Machine Tool Spindle Bearings

Adjacent structure In order to make full use of the accuracy 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 dimensional and geometric accuracy, but also has sufficient rigidity and bearing capacity. Pay particular attention to the possible large axial loads. It is recommended to provide a rigid, dimensionally stable foundation in the direction of the machine bed mounting point. Shaft and Housing Tolerance Bearing fits are derived from ISO Shaft and Housing Tolerance (ISO 286) and are linked to Bearing Bore Tolerance dmp and Bearing Outside Diameter Tolerance Dmp (DIN 620). Reference Shaft and Bore Tolerance Tables Recommended values u200bu200bfor shaft and housing tolerances apply to normal mounting and operating conditions, see table, page 37. Tolerances for FAG radial bearings with cylindrical bore 1) C/P 10. 2) C/P 10. Thrust Bearing Shaft Tolerance Rotation Conditions Bearing Type Shaft Diameter Mobility Load Tolerance Band mm Inner Ring Bearing Point Load Ball Bearings, Roller Bearings All Sizes Tapered roller bearing with adjustable inner ring h6 (j6) inner ring subjected to cyclic load or inaccurately large load direction ball bearing 100 to 200 low load 1) k6 (k5) normal load and heavy load 2) m6 (m5) greater than 200 low load m6 (m5) normal load and heavy load n6 (n5) roller bearing 60 to 200 low load k6 (k5) normal load m6 (m5) heavy load n6 (n5) 200 to 500 normal load m6 (m5) heavy load, shock load p6 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 washer h6 (j6) thrust cylindrical roller Child and cage assembly. Housing bore tolerances FAG radial bearings 1) G7 Housings made of GG are provided if the bearing outer diameter D is 250 mm and the temperature difference between the outer ring and the housing bore is 10 K. 2) F7 with housing made of GG, if the bearing outer diameter D is 250 mm and the temperature difference between the outer ring and the housing hole is 10 K. Thrust bearing housing tolerances Rotational conditions Mobility load condition tolerance zone Outer ring bearing point load Outer ring is easy to move, non-split housing tolerance class is determined according to the required running accuracy , 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 rings , The ordinary running accuracy of the split bearing seat is H7 (J7) The outer ring is easy to move and the heat is transferred from the shaft G72) The outer ring is subjected to circumferential load or low load of uncertain load direction, and the outer ring cannot move. High running accuracy selects K6, M6, N6 and P6K7 (K6) medium load, shock load, outer ring cannot move M7 (M6) heavy load, shock load (C/P 6), outer ring cannot move N7 (N6) heavy load, severe shock, thin wall housing , the outer ring cannot 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.