15. TECHNICAL DATA DEFINIONS OF SYMBOLS AND THEIR UNITS Symbols a b Cr C0r 15. 1 AXIAL DISPLACEMENT OF BEARINGS • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • (1) Contact Angle and Axial Displacement of Deep Groove Ball Bearings and Angular Contact Ball Bearings (2) Axial Load and Axial Displacement of Tapered Roller Bearings Page A 128 Ca C0a • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 128 A 128 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 130 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • (1) Surface Pressure, Maximum Stress on Fitted Surfaces and Expansion or Contraction of Raceway Diameter (2) Interferences or Clearances for Shafts and Inner Rings (3) Interferences or Clearances for Housing Bores and Outer Rings • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 130 A 130 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 130 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 15. 3 RADIAL AND AXIAL INTERNAL CLEARANCES (1) Radial and Axial Internal Clearances for Single-Row Deep Groove Ball Bearings (2) Radial and Axial Internal Clearances for Double-Row Angular Contact Ball Bearings • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 132 A 132 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 132 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 134 (1) Axial Load and Starting Torque of Tapered Roller Bearings (2) Preload and Starting Torque of Angular Contact Ball Bearings and Double-Direction Angular Contact Thrust Ball Bearings • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 15. 5 COEFFICIENTS OF FRICTION AND OTHER BEARING DATA (1) Bearing Types and Their Coefficients of Friction (2) Circumferential Speed of Rolling Elements about Their Centers and Bearing Center (3) Radial Internal Clearance and Fatigue Life A 134 A 134 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 136 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 136 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 15. 6 BRANDS AND PROPERTIES OF LUBRICATING GREASES • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • A 136 A 136 A 138 A126-141E.indd 126-127 na nc (N){kgf} ne ni (N){kgf} (N){kgf} (N){kgf} pm P Q re ri va De Di ( mm ) ( mm ) ( mm ) vc D0 Dpw Dw Housing Outside Diameter Rolling Element Pitch Diameter Nominal Rolling Element Diameter ( mm ) ( mm ) ( mm ) e E E(k) Contact Position of Tapered Roller End Face with Rib Modulus of Longitudinal Elasticity (Bearing Steel) 208 000 MPa{21 200 kgf/mm2 } β δa &a &d factor which depends on the geometry of the bearing components and on the applicable stress level h h0 k De/D D/D0 d/Di K Constant Determined by Internal Design of Bearing Fatigue Life when Effective Clearance is 0 Effective Leng of Roller Fatigue Life when Effective Clearance is & m0 αR √( ) Function of ε Axial Load, Preload Radial Load L Lwe Lε α0 —— ——2 b 1– — a Fa Fr f (ε) Distance between Centers of Curvature of Inner and Outer Rings ri + re –Dw Frictional Torque Spin Friction Z α ( mm ) Complete elliptic integral of the 2nd kind for which the population parameter is k= M Ms A 126 Symbols ( mm ) f0 15. 4 PRELOAD AND STARTING TORQUE Units ( mm ) ( mm ) Shaft Diameter, Nominal Bearing Bore Diameter Housing Bore Diameter, Nominal Bearing Outside Diameter Outer Ring Raceway Diameter Inner Ring Raceway Diameter d D 15. 2 FITS Nomenclature Contact Ellipse Major Axis Contact Ellipse Major Axis Basic Dynamic Load Rating of Radial Bearings Basic Static Load Radial of Radial Bearings Basic Dynamic Load Rating of Thrust Bearings Basic Static Load Rating of Thrust Bearings &r (N){kgf} (N){kgf} &D & De & Di ε μ ( mm ) μe μs σt max Nomenclature Rotating Speed of Rolling Elements Revolving Speed of Rolling Elements (Cape Speed) Speed of Ouder Ring Speed of Inner Ring Surface Pressure on Fitted Surface Bearing Load Rolling Element Load Groove Radius of Outer Ring Groove Radius of Inner Ring Circumferential Speed of Rolling Element about Its Center Circumferential Speed of Rolling Element about Beaing Center Number of Rolling Elements per Row Contact Angle (when axial load is applied on Radial Ball Bearning Initial Confact Angle (Geometri) (when inner and outer rings of Angular Contact Ball Bearings are pushed axially) Initial Contact Angle (Geometric) (when inner and outer rings Angular Contact Ball Bearing are pushed radially) 1/2 of Conical Angle of Roller Relative Axial Displacement of Inner and Outer Rings Axial Internal Clearance Effective Interference of Inner Ring and Shaft Radial Internal Clearance Effective Interference of Outer Ring and Housing Contraction of Outer Ring Raceway Diameter due to Fit Expansion of Inner Ring Raceway Diameter dus to Fit Units (min–1) (min–1) (min–1) (min–1) (MPa ){kgf/mm2} (N){kgf} (N){kgf} ( mm ) ( mm ) (m/sec) (m/sec) (° ) (° ) (° ) (° ) ( mm ) ( mm ) ( mm ) ( mm ) ( mm ) ( mm ) ( mm ) Load Factor Coefficient of Dynamic Friction of Rolling Bearing Coefficient of Friction between Roller End Face and Rib Coefficient of Sliding Friction Maximum Stress on Fitted Surfaces (MPa ){kgf/mm2} ( mm ) (N·mm){kgf·mm} (N·mm){kgf·mm} A 127 11/20/13 4:53:03 PM 15° 10° 5° 0 0.1 0.2 0.3 0.4 0.5 06C 10C C B 03B 04B A 06B 08B A 08 A 10 2A 1 4 A ,20A,2 18A Digits: Bearing Bore Number C…… α 0 = 15° A…… α 0 = 30° B…… α 0 = 40° 0.6 0 10B 14B 20B 18B, B 26 24A 0 500 1000 1500 2000 2500 N 0 50 100 150 200 250 kgf Axial Load Fa Fig. 15.3 Axial Load and Axial Displacement of Angular Contact Ball Bearings Remarks: Actual axial displacement may vary depending on the shaft/housing thickness, material, and fitting interference with the bearing. Please contact NSK about such factors of axial displacement which are not discussed in detail in this catalog. μm 0° 80 = 10° α0 60 α 0= 1 α 0 = 15° 40 Se rie s es HR 32 3J 06 HR 32 2 08 10 12 14 10 12 14 16 18 20 5 14 12 16 14 16 18 20 s Serie J D 3 08D HR30 D 0 1 14D 6210 6310 20 0 10 10 10 α 0 = 15 ° 0° 08 08 HR3 02J Serie s 04 α 0= Axial Displacement δa Axial Displacement δa 120 100 06 15 06 = 0° α0 140 JS eri ies Ser 03J H R3 160 06 20 μm 0 0 500 50 1000 100 1500 150 2000 200 2500 250 3000 300 Axial Load Fa Fig. 15.2 Axial Load and Axial Displacement of Deep Groove Ball Bearings A126-141E.indd 128-129 06 0.010 Fig. 15.1 Fa /Cor and Contact Angle of Deep Groove and Angular Contact Ball Bearings } 00 A Fa /Cor Fa0.9 ................. (N) δ a = 0.000077 1.9 0.9 (sin α) Z L we0.8 (mm) 0.9 0.0006 F a δa = .............. {kgf } (sin α)1.9 Z 0.9 L we0.8 A 128 04 72 A 0.005 0° (2) Axial Load F a and Axial Displacement δ a of Tapered Roller Bearings (Fig. 15.4) 14C 4C 0.015 26 20° 720 Contact Angle α } 25° 02 08 ) 20° 15° 10° 5° 0° 04 ( ) mm 25° 30° Deep Groove Ball Bearing and Angular Contact Ball Bearings (Figs. 15.1 to 15.3) 1 0.00044 Q 2 3 ................... (N) δ a = sin α Dw (mm) 1 0.002 Q 2 3 ..................... {kgf } δ a = sin α Dw Fa Q= (N), {kgf} Zsin α ( α 0=30° 08C 35° Axial Displacement δa 15. 1 Axial Displacement of Bearings (1) Contact Angle α and Axial Displacement δ a of 18 C,2 0C ,22 72 C 00 A TECHNICAL DATA 3500 N 350 kgf 0 0 1000 2000 3000 0 100 200 300 4000 N 400 kgf Axial Load Fa Fig. 15.4 Axial Load and Axial Displacement of Tapered Roller Bearings A 129 11/20/13 4:53:04 PM TECHNICAL DATA MPa kgf/mm2 kgf/mm2 MPa In case of housing outside dia. D0 ≠∞ Surface Pressure E & D (1– h2)(1– h02) pm = 2 D 1– h2 h02 E &d (1 – k2 ) In case D0 = ∞ 2 2 E &D pm = (1– h2) 2 D (In case of sold shaft) pm (MPa ) pm = {kgf/mm2} Maximum stress Maximum circumferential stress on fitted surface of σ t max inner ring bore is (MPa ) 1 + k2 {kgf/mm2} σ t max = pm 1 – k2 Expansion of inner ring raceway dia. & Di (mm) In case of solid shaft & Di Maximum circumferential stress on outer ring bore surface is 2 σ t max = pm 1– h2 In case D0 ≠∞ & De = & D · h = &d . k Contraction of outer ring raceway dia. & De (mm) 5 4 3 50 40 30 2 20 250 25 200 20 100 10 p6 n6 k5 10 js5 5 4 3 0.5 0.4 0.3 0.2 2 0.1 1 20 30 50 70 100 200 300 50 40 30 5 4 3 20 2 10 1 5 500 mm 0.5 5 4 3 50 40 30 2 20 p6 n6 m5 k5 100 10 1 10 0.5 0.4 0.3 5 4 3 0.2 2 20 30 50 70 100 200 300 50 40 5 4 30 3 20 2 10 500 mm 1 Nominal Bearing Bore Diameter d (Class Normal) Fig. 15.5 Surface Pressure m and Maximum Stress σ t max for Average Fitting Interference In case D0 = ∞ 400 40 300 30 250 25 200 20 150 15 js5 Nominal Bearing Bore Diameter d (Class Normal) 1– h02 1– h2 h02 MPa kgf/mm2 10 100 150 15 m5 1 kgf/mm2 MPa m Housing & Bore & Outer Ring Surface Pressure Shaft & Inner Ring Maximum Stress σ t max Items Maximum Stress σ t max Table. 15. 1 Surface Pressure, Maximum Stress on Fitted Surfaces and Expansion or Contraction m (1) Surface Pressure p m , Maximum Stress σ tmax on Fitted Surfaces and Expansion of Inner Ring Raceway Diameter & Di or Contraction of Outer Ring Raceway Diameter & De (Table 15.1, Figs. 15.5 and 15.6) (2) Interferences or Clearances of Shafts and Inner Rings (Table 15.2) (3) Interferences or Clearances of Housing Bores and Outer Rings (Table 15.3) Surface Pressure 15.2 Fits Fig. 15.6 Surface Pressure m and Maximum Stress σ t max for Maximum Fitting Interference & De = & D · h Remarks The modulus of longitudinal elasticity and Poisson's ratio for the shaft and housing material are the same as those for inner and outer rings. Reference 1 MPa =1 N/ mm2= 0.102 kgf / mm2 Table 15. 2 Interferences or Clearances Single Plane Size Mean Bore Classification Dia. Deviation (Normal) (mm) & d mp over incl. high low 3 6 10 6 10 18 0 0 0 18 30 50 30 50 65 65 80 100 Interferences or Clearances for f6 g5 Clearance g6 h5 h6 js5 min. – 8 – 8 – 8 18 22 27 2 5 8 9 11 14 4 3 2 12 14 17 4 3 2 5 6 8 8 8 8 8 9 11 8 8 8 0 0 0 – 10 – 12 – 15 33 41 49 10 13 15 16 20 23 3 3 5 20 25 29 3 3 5 9 11 13 10 12 15 13 16 19 10 12 15 4.5 5.5 6.5 80 100 120 0 0 0 – 15 – 20 – 20 49 58 58 15 16 16 23 27 27 5 8 8 29 34 34 5 8 8 13 15 15 15 20 20 19 22 22 15 20 20 120 140 160 140 160 180 0 0 0 – 25 – 25 – 25 68 68 68 18 18 18 32 32 32 11 11 11 39 39 39 11 11 11 18 18 18 25 25 25 25 25 25 180 200 225 200 225 250 0 0 0 – 30 – 30 – 30 79 79 79 20 20 20 35 35 35 15 15 15 44 44 44 15 15 15 20 20 20 30 30 30 250 280 315 280 315 355 0 0 0 – 35 – 35 – 40 88 88 98 21 21 22 40 40 43 18 18 22 49 49 54 18 18 22 23 23 25 355 400 450 400 450 500 0 0 0 – 40 – 45 – 45 98 108 108 22 23 23 43 47 47 22 25 25 54 60 60 22 25 25 25 27 27 Remarks max. max. max. max. max. max. max. max. Units : μm Each Fitting Class js6 j5 Inter- Clearance Inter- Clearance Inter- Clearance Inter- Clearance Inter- Clearance InterClearance ference ference ference ference ference ference max. of Shafts and Inner Rings j6 k5 Inter- Clearance Inter- Interference Clearance ference ference k6 m5 m6 n6 p6 r6 Size Classification (mm) Interference Interference Interference Interference Interference Interference min. max. min. max. min. max. min. max. min. min. max. min. max. over incl. — 15 16 — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 3 6 10 6 10 18 4 5 7 19 23 27 2 2 2 21 25 30 2 2 2 25 30 36 — 9 11 — 32 39 — 9 11 — 37 45 — — — — — — — — — — — — — — — — — — 18 30 50 30 50 65 9.5 24.5 11 31 11 31 7 9 9 27 33 33 2 3 3 30 38 38 2 3 3 36 45 45 11 13 13 39 48 48 11 13 13 45 55 55 20 23 23 54 65 65 — 37 37 — 79 79 — — — — — — 65 80 100 80 100 120 32 32 32 12.5 37.5 12.5 37.5 12.5 37.5 11 11 11 39 39 39 3 3 3 46 46 46 3 3 3 53 53 53 15 15 15 58 58 58 15 15 15 65 65 65 27 27 27 77 77 77 43 43 43 93 93 93 63 65 68 113 115 118 120 140 160 140 160 180 13 13 13 37 37 37 14.5 44.5 14.5 44.5 14.5 44.5 13 13 13 46 46 46 4 4 4 54 54 54 4 4 4 63 63 63 17 17 17 67 67 67 17 17 17 76 76 76 31 31 31 90 90 90 50 50 50 109 109 109 77 80 84 136 139 143 180 200 225 200 225 250 46.5 46.5 52.5 16 16 18 42 42 47 16 16 18 51 51 58 16 16 18 51 51 58 4 4 4 62 62 69 4 4 4 71 71 80 20 20 21 78 78 86 20 20 21 87 87 97 34 34 37 101 101 113 56 56 62 123 94 123 98 138 108 161 165 184 250 280 315 280 315 355 52.5 58.5 58.5 18 20 20 47 52 52 18 20 20 58 65 65 18 20 20 58 65 65 4 5 5 69 77 77 4 5 5 80 90 90 21 23 23 86 95 95 21 23 23 97 108 108 37 40 40 113 125 125 62 68 68 138 114 153 126 153 132 190 211 217 355 400 450 400 450 500 max. max. max. max. max. max. max. max. — 3 4 — 11 12 — 2 3 — 12 13 — — 4.5 12.5 5.5 13.5 — 2 3 14.5 17.5 21.5 4 5 7 15 18 21 6.5 16.5 8 20 9.5 24.5 6.5 7.5 7.5 21.5 27.5 27.5 7 9 9 21 26 26 25 25 25 9 9 9 34 34 34 11 11 11 29 29 29 30 30 30 10 10 10 40 40 40 35 35 40 32 32 36 35 35 40 11.5 11.5 12.5 40 45 45 36 40 40 40 45 45 12.5 13.5 13.5 max. 1. The figures for tolerance classes where stress caused by the fitting of the shaft and inner ring becomes excessive are omitted. 2. The tolerance range js is now recommended instead of j. A 130 A126-141E.indd 130-131 A 131 11/20/13 4:53:06 PM TECHNICAL DATA Table 15. 3 Interferences or Single Plane Mean O. D. Size Deviation Classification (Normal) (mm) & D mp over incl. high 6 10 18 10 18 30 0 0 0 – – – 30 50 80 50 80 120 120 150 180 250 315 400 Interferences or Clearances for low G7 H6 H7 H8 Clearance Clearance Clearance Clearance max. min. 8 8 9 28 32 37 0 0 0 – 11 – 13 – 15 150 180 250 0 0 0 315 400 500 500 630 630 800 800 1 000 J6 JS6 Clearances of Housing Bores and Outer Rings J7 JS7 Inter- Clearance Inter- Clearance InterClearance ference ference ference max. min. max. min. max. min. max. max. max. max. 5 6 7 17 19 22 0 0 0 23 26 30 0 0 0 30 35 42 0 0 0 13 14 17 4 5 5 12.5 13.5 15.5 4.5 5.5 6.5 45 53 62 9 10 12 27 32 37 0 0 0 36 43 50 0 0 0 50 59 69 0 0 0 21 26 31 6 6 6 19 22.5 26 – 18 – 25 – 30 72 79 91 14 14 15 43 50 59 0 0 0 58 65 76 0 0 0 81 88 102 0 0 0 36 43 52 7 7 7 0 0 0 – 35 – 40 – 45 104 115 128 17 18 20 67 76 85 0 0 0 87 97 108 0 0 0 116 129 142 0 0 0 60 69 78 0 0 0 – 50 – 75 –100 142 179 216 22 24 26 94 125 156 0 0 0 120 155 190 0 0 0 160 200 240 0 0 0 — — — max. Units : μm Each Fitting Class K6 K7 M6 M7 N6 N7 P6 Size Classification (mm) P7 Inter- Clearance Inter- Clearance Inter- Clearance Inter- Clearance Inter- Clearance Inter- Clearance Inter- Interference Clearance ference ference ference ference ference ference ference Interference max. max. max. min. max. over incl. 16 18 21 7 8 9 15 17 19 7 9 10 10 10 11 7 9 11 13 14 15 10 12 15 5 4 5 12 15 17 8 8 9 15 18 21 1 1∗ 2∗ 16 20 24 4 3 2 19 23 28 4 7 9 21 26 31 1 3 5 24 29 35 6 10 18 10 18 30 8 9.5 11 25 31 37 11 12 13 23 28 32 12 15 17 14 17 19 13 15 18 18 22 25 18 21 25 7 8 9 20 24 28 11 13 15 25 30 35 1∗ 1∗ 1∗ 28 33 38 3 4 5 33 39 45 10 13 15 37 45 52 6 8 9 42 51 59 30 50 80 50 80 120 30.5 37.5 44.5 12.5 12.5 14.5 44 51 60 14 14 16 38 45 53 20 20 23 22 29 35 21 21 24 30 37 43 28 28 33 10 17 22 33 33 37 18 25 30 40 40 46 2∗ 5 8 45 45 51 6 13 16 52 52 60 18 11 11 61 61 70 10 3 3 68 68 79 120 150 180 150 180 250 7 7 7 51 58 65 16 18 20 71 79 88 16 18 20 61 68 76 26 28 31 40 47 53 27 29 32 51 57 63 36 40 45 26 30 35 41 46 50 35 40 45 52 57 63 10 14 18 57 62 67 21 24 28 66 73 80 12 11 10 79 87 95 1 1 0 88 98 108 250 315 400 315 400 500 — — — 72 100 128 22 25 28 — — — — — — 85 115 145 35 40 45 50 75 100 44 50 56 50 75 100 70 80 90 24 45 66 70 80 90 24 45 66 96 110 124 6 25 44 88 100 112 6 25 44 114 130 146 28 13 0 122 138 156 28 13 0 148 168 190 500 630 630 800 800 1 000 max. max. max. max. max. max. max. max. max. max. max. max. max. max. Note (∗) Indicates the minimum interference Remarks The tolerance range JS is now recommended instead of J. 15.3 Radial and Axial Internal Clearances Table 15. 4 Constant K (2) Radial Internal Clearance & r and Axial Internal Clearance & a in Double-Row Angular Contact Ball Bearings (Fig. 15.8) &a = 2 √ & m 0 – m 0 cosα R – r 2 2 ( – 2 m 0 sinα R A 132 A126-141E.indd 132-133 ) 2 (mm) 1.14 1.06 1.06 1.11 1.07 1.20 1.19 1.37 1.45 1.57 1.64 1.70 2.09 1.82 1.88 1.95 2.01 2.06 2.11 2.16 2.25 2.32 2.40 2.40 2.49 2.59 2.59 62Series 24~30 21, 22 16, 17 13~15 10~11 07 04~06 00~02 0.50 0.30 0.20 63Series 28, 30 22, 24 17~19 15, 16 10, 11 07 05, 06 01~04 µm 0.10 160Series 26~30 21~24 16~17 11~13 06~08 01~03 0.05 0.04 0.03 60Series 22~28 21 16~17 11~13 07~10 02~05 01 80 ° 63XX 0.93 0.93 0.93 0.99 1.06 1.06 1.07 1.25 1.29 1.29 1.33 1.40 1.50 1.54 1.57 1.57 1.64 1.70 1.76 1.82 1.88 1.95 2.01 2.06 2.11 2.11 2.11 ot 25 62XX — 0.80 0.93 0.93 0.96 0.96 1.01 1.06 1.06 1.11 1.11 1.20 1.20 1.20 1.29 1.29 1.37 1.37 1.44 1.44 1.44 1.54 1.64 1.64 1.70 1.70 1.76 rc 1 2 60XX — 0.80 0.80 0.80 0.90 0.90 0.96 0.96 0.96 1.01 1.01 1.06 1.06 1.06 1.16 1.16 1.20 1.20 1.29 1.29 1.29 1.37 1.40 1.40 1.54 1.54 1.57 & K = 2 (re + r i – Dw) 160XX 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 24 26 28 30 5320 5315 5310 5305 a= where Bore No. 60 & (mm) 1.00 Axial Internal Clearance & a & aHK & r 1 2 mm Values of K Axial Internal Clearance & a (1) Radial Internal Clearance & r and Axial Internal Clearance & a in Single-Row Deep Groove Ball Bearings (Fig. 15.7) 5220 40 5215 5205 5210 5200 20 0 0.02 0.001 0.003 0.005 0.01 0.02 0.03 0.05 0.1 Radial Internal Clearance & r Fig. 15.7 & r and & a in Single-Row Deep Groove Ball Bearings 0.2 mm 0 10 20 30 40 Radial Internal Clearance & r 50 µm Fig. 15.8 & r and & a in Double-Row Angular Contact Ball Bearings (52, 53 Series) A 133 11/20/13 4:53:07 PM TECHNICAL DATA (N·mm), {kgf·mm} M = e μe Fa cosβ where μe : 0.20 When bearings with the same number are used in opposition, the torque M caused by the preload becomes 2M. M = Ms Z sinα where Ms is spin friction 3 Ms = — μs Q a E(k) 8 μs = 0.15 When bearings with the same number are used in opposition, the torque M caused by the preload becomes 2M. F 2β 0 μe Qf e (N·mm), {kgf·mm} where Dw1 Qf (N·mm), {kgf·mm} L Starting Torque of Duplex Bearings (for two bearings) 2M (1) Axial Load Fa and Starting Torque M of Tapered Roller Bearings (Figs. 15.9 and 15.10) Qe kgf . mm N . mm (2) Preload Fa and Starting Torque M of Angular Contact Ball Bearings and Double-Direction Angular Contact Thrust Ball Bearings (Figs. 15.11 and 15.12) 15. 4 Preload and Staring Torque 30 300 20 200 22 10 22 20 0 14 1 00 ries Se 70C Qi α 100 0 20 16 ,10 8 08 1 4 1 , 12 06 04 02 00 ies Ser 72C 0 Fig. 15.9 Relation between e and β 0 500 1000 1500 2000 N 0 50 100 150 200 kgf Preload Fa Fig. 15.11 Preload and Starting Torque for Back-to-Back or Face-to-Face Arrangements of Angular Contact Ball Bearings (α =15°) kgf·mm N·mm 5000 500 kgf . mm N . mm 14 12 4000 400 70 10 14 14 D 200 12 D 10 10 100 14 1000 08 06 0 0 10 5000 0 500 er ies HR 30 3 04 s 06 08D 06 04 S s 3J rie 30 Se HR 2J 30 R H 0 06 D 08 18 ,16 12 14 2000 60 Se DJ rie s HR 32 Se 2J rie 600 280TAC20 240TAC20 200TAC20 150TAC20 100TAC20 80TAC20 08 Starting Torque M 300 3000 16 Starting Torque M 18 700 rie s 10000 1000 Axial Load Fa Fig. 15.10 Relation between Axial Load and Starting Torque of Tapered Roller Bearings Se 3J 2 3 HR 15000 1500 50 40 30 500 400 60TAC20 50TAC20 40TAC20 300 20 200 10 100 0 0 240TAC29 170TAC29 140TAC29 120TAC29 100TAC29 80TAC29 60TAC29 N kgf 0 1000 0 100 2000 200 3000 300 4000 400 5000 500 6000 600 7000 700 8000 800 9000 900 N kgf Preload Fa Fig. 15.12 Preload and Starting Torque of Double-Direction Angular Contact Thrust Ball Bearings A 134 A126-141E.indd 134-135 A 135 11/20/13 4:53:08 PM TECHNICAL DATA 15.5 Coefficients of Dynamic Friction and Other Bearing Data (3) Radial Internal Clearance & r and Fatigue Life L (Fig. 15.13) (1) Bearing Types and Their Coefficients of Dynamic Friction μ For the radial internal clearance & r and the function f (ε) of the load factor, the following equations are valid: Table 15. 7 ε and f (ε ), Lε /L Deep Groove Ball Bearings ε For Deep Groove Ball Bearings μ= M d P⋅ f (ε ) = 2 Table 15.5 Coefficients of Dynamic Friction Bearing Types Approximate values of μ Deep Groove Ball Bearings Angular Contact Ball Bearings Self-Aligning Ball Bearings Thrust Ball Bearings 0.0013 0.0015 0.0010 0.0011 Cylindrical Roller Bearings Tapered Roller Bearings Spherical Roller Bearings 0.0010 0.0022 0.0028 Needle Roller Bearings with Cages Full Complement Needle Roller Bearings Spherical Thrust Roller Bearings f (ε ) = 1 w 3 &r ⋅ D & r ⋅ Dw 1 3 ....................................{kgf} 2 3 ( ) 0.002 Fr Z ....................................(N) 2 3 ( ) 0.00044 Fr Z For Cylindrical Roller Bearings f (ε ) = & r ⋅ L we0.8 0.000077 f (ε ) = 0.0015 0.0025 ( FZ ) r & r ⋅ L we 0.9 ..................................(N) 0.8 ( ) 0.0006 Fr Z 0.9 ..................................{kgf} Cylindrical Roller Bearings Lε ⎯ L f (ε) Lε ⎯ L f (ε) 0.1 0.2 0.3 33.713 10.221 4.045 0.294 0.546 0.737 51.315 14.500 5.539 0.220 0.469 0.691 0.4 0.5 0.6 1.408 0 0.889 1.0 1.069 1.887 0 − 0.859 − 1.133 0.870 1.0 1.075 0.7 0.8 0.9 − 1.438 − 1.862 − 2.195 1.098 1.094 1.041 − 1.897 − 2.455 − 2.929 1.096 1.065 0.968 1.0 1.25 1.5 − 2.489 − 3.207 − 3.877 0.948 0.605 0.371 − 3.453 − 4.934 − 6.387 0.805 0.378 0.196 1.67 1.8 2.0 − 4.283 − 4.596 − 5.052 0.276 0.221 0.159 − 7.335 − 8.082 − 9.187 0.133 0.100 0.067 2.5 3 4 − 6.114 − 7.092 − 8.874 0.078 0.043 0.017 −11.904 −14.570 −19.721 0.029 0.015 0.005 −10.489 −17.148 0.008 0.001 −24.903 −48.395 0.002 0.0002 5 10 The relation between the load factor ε and f (ε ) and L ε / L , when the radial internal clearance is & r is as shown in Table 15.7. From the above equations, first obtain f (ε ) and then ε and L ε / L can be obtained. 0.0028 (2) Circumferential Speeds of Rolling Elements about Their Centers and Bearing Center 1.0 Rotating inner ring, fixed outer ring Ball rotating speed na (min–1) Dpw cos2 α n i − − Dw Dpw/Dw 2 ( ) Rotating outer ring, fixed inner ring + ( DD pw w − cos2 α n e Dpw/Dw 2 ) Life Ratio Items Lε L Table 15.6 Circumferential Speeds of Rolling Elements about Their Centers and Bearing Center P=Cr/5 6208 P=Cr/10 Cr=29 100 N P=Cr/15 0.8 0.6 0.4 Cicumferential speed around bearing ball's center υ a (m/sec) Revolving speed around bearing center nc (min–1) Cicumferential speed around bearing center υ c (m/sec) Dpw ⋅ cos2 α n i − π Dw − 3 60 ×10 (D ( + 1− w Dpw/Dw )2 cos α n i Dpw/Dw 2 ) Dpw ⋅ cos2 α n e + π Dw − 3 60 × 10 (D ( + 1− w Dpw/Dw )2 cos α n e Dpw/Dw 2 ) 0.2 NU208 P=Cr/5 Cr=43 500 N P=Cr/10 P=Cr/15 −60 −40 −20 0 20 40 60 80 100 Radial Internal Clearance & r ⋅ cos α − π Dpw 1 − 3 60 × 10 ( Dpw/Dw ni )2 ⋅ cos α n e + π Dpw 1 − 3 60 × 10 ( Dpw/Dw )2 120 μm Fig. 15.13 Radial Internal Clearance and Life Ratio Remarks 1. + sign indicates CW rotation and − sign CCW Remarks 2. The revolving speed and circumferential speed of the rolling elements are the same as those of the cage. A 136 A126-141E.indd 136-137 A 137 11/20/13 4:53:09 PM TECHNICAL DATA 15. 6 BRANDS AND PROPERTIES OF LUBRICATING GREASES Table 15. 8 Brands of Lubricating Greases and Comparison of Properties Working Temperature Range(1)(°C) Thickeners Base Oils Dropping Point (˚C) Consistency ADLEX Lithium Mineral oil 198 300 0 to +110 APOLOIL AUTOLEX A Lithium Mineral oil 198 280 −10 to +110 Brands Pressure Resistance Usable Limit Compared to Listed Limiting Speed(2)(%) Good 70 Fair 60 Lithium/Calcium Mineral oil 177 294 −10 to + 80 Fair 70 EA2 GREASE Urea (3) Poly-α-olefin oil ≥260 243 −40 to +150 Fair 100 EA3 GREASE Urea (3) Poly-α-olefin oil ≥260 230 −40 to +150 Fair 100 EA5 GREASE Urea (3) Poly-α-olefin oil ≥260 251 −40 to +160 Good 60 EA7 GREASE Urea (3) Poly-α-olefin oil ≥260 243 −40 to +160 Fair 100 ENC GREASE Urea (3) Polyol ester oil + Mineral oil (4) ≥260 262 −40 to +160 Fair 70 ENS GREASE Urea (3) Polyol ester oil (4) ≥260 264 −40 to +160 Poor 100 ARAPEN RB 300 Lithium Poly-α-olefin oil ≥260 235 −10 to +120 Fair 100 Barium Complex Ester oil + Mineral oil (4) ≥260 280 −30 to +120 Poor 100 ISOFLEX SUPER LDS 18 Lithium Ester oil (4) 195 280 −50 to +110 Poor 100 ISOFLEX TOPAS NB 52 Barium Complex Poly-α-olefin oil ≥260 280 −40 to +130 Poor 90 DOW CORNING SH 33 L GREASE Lithium Silicone oil (5) 210 310 −60 to +120 Poor 60 DOW CORNING SH 44 M GREASE Lithium Silicone oil (5) 210 260 −30 to +130 Poor 60 NS HI-LUBE Lithium Polyol ester oil + Diester oil (4) 192 250 −40 to +130 Fair 100 NSC GREASE Lithium Alkyldiphenyl ether oil + Polyol ester oil (4) 192 235 −30 to +140 Fair 70 NSK CLEAN GREASE LG2 Lithium Poly-α-olefin oil + Mineral oil 201 199 −40 to +130 Poor 100 EMALUBE 8030 Urea (3) Mineral oil ≥260 280 0 to +130 Good 60 MA8 GREASE Urea (3) Alkyldiphenyl ether oil + Poly-α-olefin oil ≥260 283 −30 to +160 Fair 70 ECE GREASE ISOFLEX NBU 15 KRYTOX GPL-524 PTFE Perfluoropolyether oil ≥260 265 0 to +200 Fair 70 KP1 GREASE PTFE Perfluoropolyether oil ≥260 280 −30 to +200 Fair 60 Sodium Terephtalamate Polyol ester oil + Mineral oil (4) ≥230 227 −40 to +130 Poor 100 G-40M Lithium Silicone oil (5) 223 252 −30 to +130 Poor 60 SHELL GADUS S2 V220 2 Lithium Mineral oil 187 276 0 to + 80 Good 60 COSMO WIDE GREASE WR No.3N SHELL ALVANIA GREASE S1 Lithium Mineral oil 182 323 −10 to +110 Fair 70 SHELL ALVANIA GREASE S2 Lithium Mineral oil 185 275 −10 to +110 Fair 70 185 242 −10 to +110 Fair 70 ≥240 280 0 to +120 Fair 70 70 SHELL ALVANIA GREASE S3 CASSIDA GREASE RLS 2 Lithium Mineral oil Aluminum Complex Poly-α-olefin oil SHELL SUNLIGHT GREASE 2 Lithium Mineral oil 200 274 −10 to +110 Fair WPH GREASE Urea (3) Poly-α-olefin oil 259 240 −40 to +150 Fair 70 PTFE Perfluoropolyether oil ≥260 280 −30 to +200 Fair 60 DEMNUM GREASE L-200 NIGACE WR-S Urea (3) Synthetic oil ≥260 230 −30 to +150 Poor 70 NIGLUBE RSH Sodium Complex Polyalkylene Glycol oil ≥260 270 −20 to +120 Fair 60 Notes (1) If grease will be used at the upper or lower limit sufficient of the temperature range or in a special environment such as vacuum, it is advisable to consult NSK. Notes (2) For short-term operation or when cooling is grease may be used at speeds exceeding the above limits provided the supply of grease is appropriate. Notes (3) Urea-based grease causes fluorine-based material to deteriorate. Notes (4) Ester-based grease causes acrylic rubber material to swell. Notes (5) Silicone-based grease causes silicone-based material to swell. A 138 A126-141E.indd 138-139 (continued on next page) A 139 11/20/13 4:53:10 PM TECHNICAL DATA Brands Thickeners Base Oils Dropping Point (˚C) Consistency Working Temperature Range(1)(°C) Pressure Resistance Usable Limit Compared to Listed Limiting Speed(2)(%) PALMAX RBG Lithium Complex Mineral oil 216 300 −10 to +130 Good 70 BEACON 325 Lithium Diester oil (4) 190 274 −50 to +100 Poor 100 MULTEMP PS No.2 100 Lithium Poly-α-olefin oil + Diester oil (4) 190 275 −50 to +110 Poor MOLYKOTE FS-3451 GREASE PTFE Fluorosilicone oil (5) ≥260 285 0 to +180 Fair 70 UME GREASE Urea Mineral oil ≥260 268 −10 to +130 Fair 70 RAREMAX AF-1 Urea Mineral oil ≥260 300 −10 to +130 Fair 70 Notes (1) If grease will be used at the upper or lower limit sufficient of the temperature range or in a special environment such as vacuum, it is advisable to consult NSK. Notes (2) For short-term operation or when cooling is grease may be used at speeds exceeding the above limits provided the supply of grease is appropriate. Notes (3) Urea-based grease causes fluorine-based material to deteriorate. Notes (4) Ester-based grease causes acrylic rubber material to swell. Notes (5) Silicone-based grease causes silicone-based material to swell. A 140 A126-141E.indd 140-141 A 141 11/20/13 4:53:11 PM