Technical Data. 17. Technical data Deep groove ball bearing radial internal clearances and axial internal clearances A

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1 7. Technical data 7. Deep groove ball bearing radial internal clearances and axial internal clearances Fig. 7.. Series 68 radial internal/axial internal clearances Fig. 7.. Series 6 radial internal/axial internal clearances Fig. 7.. Series 69 radial internal/axial internal clearances Fig. 7.. Series 6 radial internal/axial internal clearances A-

2 This data is based on typical dimensions. NTN do not guarantee at this data. 7. Angular contact ball bearing axial load and axial displacement Fig. 7.. Series 7 axial load and axial displacement Fig. 7.. Series 79 axial load and axial displacement B 7B 7B 7B 7B 7B..... Fig. 7.. Series 7 axial load and axial displacement..... Fig. 7.. Series 7 B axial load and axial displacement... 7B 7B 7B 7B 7B 7B..... Fig. 7.. Series 7 B axial load and axial displacement A-

3 This data is based on typical dimensions. NTN do not guarantee at this data. 7. Tapered roller bearing axial load and axial displacement 7. Allowable axial load for ball bearings... T-X T-X XU XU.... Allowable axial load kn Bearing bore diameter mm 6 series 6 series 6 series 69 series 68 series FIg. 7.. Series axial load and axial displacement Fig. 7.. Allowable axial load for deep groove ball bearings.. 9XU 9XU 9XU.... Allowable axial load kn 79 series Bearing bore diameter mm 7 series 7 series 7B series 7B series 7 series Fig. 7.. Series 9 axial load and axial displacement Fig. 7.. Allowable axial load for angullar contact ball bearings.. T- T- U U T-D T-D DU Note: When an axial load acts upon deep groove or angular contact ball bearings, allowable axial load is the load whereby the contact ellipse exceeds the shoulder of the raceway..... FIg. 7.. Series / D axial load and axial displacement Note: Values when bearing and housing are rigid bodies. Axial displacement may become large depending on shape of shaft/housing and fitting conditions. A-

4 7. Fitting surface pressure Table 7.. lists equations for calculating the pressure and maximum stress between fitting surfaces. Table 7.. can be used to determine the approximate average groove diameter for bearing inner and outer rings. The effective interference, in other words the actual interference Δdeff after fitting, is smaller than the apparent interference Δd derived from the measured valued for the bearing bore diameter and shaft. This difference is due to the roughness or variations of the finished surfaces to be fitted, and therefore it is necessary to assume the following reductions in effective interference: For ground shafts:..μm For lathed shafts :. 7.μm Table 7.. Fitting surface pressure and maximum stress Fit conditions quation Codes (units: N kgf, mm) Fitting surface pressure Solid steel shaft/ inner ring fit Hollow steel shaft/ inner ring fit Δdeff d Δdeff Δd d - ( ) Di - (d / Di) - (do / d) - (do / Di) d Shaft diameter, inner ring bore diameter do Hollow shaft inner diameter Di Inner ring average groove diameter Δdeff ffective interference lasticity factor = 8, MPa, kgf / mm do d Di MPa kgf / mm Steel housing/ outer ring fit ΔDeff D - (Do / D) - (D / Dh) - (Do /Dh) D : Housing inner diameter, bearing outer diameter Do : Outer ring average groove diameter Dh : Housing outer diameter ΔDeff : ffective interference Do D Dh Maximum stress MPa kgf / mm Shaft / inner ring fit Housing/ outer ring fit + (d / Di) t max = P (d / Di) t max = P (Do / D) Inner ring bore diameter face maximum tangential stress Outer ring inner diameter face maximum tangential stress Table 7.. Average groove diameter (approximate expression) Bearing type Average groove diameter Inner ring (Di ) Outer ring (Do ) Deep groove ball bearings. d + D.9 d + D Cylindrical roller bearings. d + D.98 d + D Spherical roller bearings d + D.97 d + D d: Inner ring bore diameter mm D: Outer ring outer diameter mm Average groove diameter values shown for double-flange type. A-

5 Fitting surface pressure Pm kgf/mm MPa MPa Fig. 7.. Average fit interference as it relates to surface pressure Pm and max. stress σt max js n6 m Nominal bearing bore diameter (Class ) mm k p6 kgf/mm t max. Maximum stress 7.6 Necessary press fit and pullout force quations (7.) and (7.) below can be used to calculate the necessary pullout force for press fit for inner rings and shafts or outer rings and housings. For shaft and inner rings: Kd = μ P π d B (7.) For housing and outer rings: KD = μ P π D B (7.) Where, Kd : Inner ring press fit or pullout force N{kgf} KD : Outer ring press fit or pullout force N{kgf} P : Fitting surface pressure MPa{kgf/mm } (Refer to Table 7..) d : Shaft diameter, inner ring bore diameter mm D : Housing inner diameter, outer ring outer diameter mm B : Inner or outer ring width μ : Sliding friction coefficient (Refer to Table 7.6.) Fitting surface pressure Pm kgf/mm MPa MPa kgf/mm p6 n6 m k js Nominal bearing bore diameter (Class ) mm t max Maximum stress Table 7.6. Press fit and pullout sliding friction coefficient Type Inner (outer) ring press fit onto cylindrical shaft (bore) Inner (outer) ring pullout from cylindrical shaft (bore) Inner ring press fit onto tapered shaft or sleeve Inner ring pullout from tapered shaft Sleeve press fit onto shaft/bearing Sleeve pullout from shaft/bearing Fig. 7.. Maximum fit interference as it relates to surface pressure Pm and max. stress σt max For recommended fitting, see page A-. A-