Ball and Roller Bearings - Ntn-snr.com

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Bearing Fits 7.3.2 Recommended Fits Bearing fit is governed by the selection tolerances for bearing shaft diameters and housing bore diameters. Widely used fits for 0 Class tolerance bearings and various shaft and housing bore diameter tolerances are shown in Table 7.1. Generally-used, standard fits for most types of bearings and operating conditions are shown in Tables 7.2 - 7.7. Table 7.2: Fits for radial bearings Table 7.3: Fits for thrust bearings Table 7.4: Fits for electric motor bearings Table 7.6: Fits for inch series tapered roller bearings (ANSI Class 4) Table 7.7: Fits for inch series tapered roller bearings (ANSI Class 3 and 0) Table 7.5. shows fits and their numerical values. For special fits or applications, please consult NTN Engineering. 7.3.3 Interference minimum and maximum values The following points should be considered when it is necessary to calculate the interference for an application: ¡In calculating the minimum required amount of interference keep in mind that: 1) interference is reduced by radial loads 2) interference is reduced by differences between bearing temperature and ambient temperature 3) interference is reduced by variation of fitted surfaces ¡Maximum interference should be no more than 1:1000 of the shaft diameter or outer diameter. Required interference calculations are shown below. (1) Radial loads and required interference Interference between inner rings mounted on solid shafts is reduced when acted upon by radial loads. Calculation of the minimum required amount of interference in such cases is shown in formulae (7.1) and (7.2). Fr 0.3 Cor ∆ dF 0.08 (dFr / B) 1/2 N 0.25 (dFr / B) 1/2 kgf (7.1) Fr 0.3 Cor ∆ dF 0.02 (Fr / B) N 0.2 (Fr / B) kgf (7.2) Where, ∆ dF : Required effective interference for load m d : Nominal bore diameter mm B : Inner ring width mm Fr : Radial load Nkgf Cor : Basic static rated load Nkgf shown in formulae (7.1). ∆ dT = 0.0015 d ∆T (7.3) ∆ dT : Required effective interference for temperature difference m ∆T : Difference between bearing temperature and ambient temperature ˚C d : Bearing bore diameter mm (3) Fitted surface variation and required interference Interference between fitted surfaces is reduced by roughness and other slight variations of these surfaces which are flattened in the fitting process. The degree of reduced interference depends upon the finish treatment of these surfaces, but in general it is necessary to assume the following interference reductions. For ground shafts: 1.02.5m For lathed shafts: 5.07.0m (4) Maximum interference When bearing rings are installed with an interference fit, tension or compression stress may occur along their raceways. If interference is too great, this may cause damage to the rings and reduce bearing life. For these reasons, maximum interference should not exceed the previously mentioned ratio of 1:1,000 of shaft or outside diameter. 7.3.4 Other details (1) Tight interference fits are recommended for, ¡Operating conditions with large vibration or shock loads ¡Applications using hollow shafts or housings with thin walls ¡Applications using housings made of light alloys or plastic (2) Loose interference fits are preferable for, ¡Applications requiring high running accuracy ¡Applications using small sized bearings or thin walled bearings Class 0 ∆Dmp G6 G7 H8 H7 H6 Loose fit Transition fit J6 J7 K6 K7 Types of fits Housing Transition fit M6 M7 N6 N7 P6 P7 Tight fit Tight fit (2) Temperature difference and required interference Interference between inner rings and steel shafts is reduced as a result of temperature increases (difference between bearing temperature and ambient temperature, ∆T) caused by bearing rotation. Calculation of the minimum required amount of interference in such cases is n5 n6 m5 m6 k5 k6 Class 0 J5 J6 ∆dmp h5 h6 g5 g6 Shafts Fig 7.1 p6 A-48
Bearing Fits (3) Consideration must also be given to the fact that fit selection will effect internal bearing clearance selection. (refer to page insert A-56) (4) A particular type of fit is recommended for SL type cylindrical roller bearings. Table 7.2 General standards for radial bearing fits (JIS Class 0, 6, 6X) Table 7.2 (1) Load conditions, magnitude Ball bearing Load Nature conditions, of load Fit Shaft diameter magnitude mm over incl Tolerance class Cylindrical roller bearing Tapered roller bearing Shaft diameter mm over incl Tolerance class Spherical roller bearings Shaft diameter mm over incl Tolerance class Remarks Indeterminate direction load Rotating inner ring load Tight fit / Transition fit 1 Light or fluctuating variable load 1 Normal load 1 Heavy load or shock load 18 18 100 100 200 18 18 100 100 140 140 200 200 280 h5 js6 k6 js5 k5 m5 m6 n6 40 40 140 140 200 40 40 100 100 140 140 200 200 400 50 140 140 200 200 js6 k6 m6 k5 m5 m6 n6 p6 n6 p6 r6 40 65 100 140 280 40 65 100 140 280 500 50 100 100 140 140 200 k5 m5 m6 n6 p6 r6 n6 p6 r6 When greater accuracy is required js5, k5, and m5 may be substituted for js6, k6, and m6. Alteration of inner clearances to accommodate fit is not a consideration with single-row angular contact bearings and tapered roller bearings. Therefore, k5 and m5 may be substituted for k6 and m6. Use bearings with larger internal clearances than CN clearance bearings. Static inner ring load Transition fit Inner ring axial displacement possible Inner ring axial displacement unnecessary All shaft diameters g6 h6 All shaft diameters g6 h6 All shaft diameters g6 h6 When greater accuracy is required use g5. For large bearings, f6 may be used. When greater accuracy is required use h5. Centric axial load only Transition fit All loads All shaft diameters js6 All shaft js6 All shaft js6 diameters diameters General; depending on the fit, shaft and inner rings are not fixed. Table 7.2 (2) Fit with shaft (fits for tapered bore bearings (Class 0) with adapter assembly/withdrawal sleeve) 2 All loads All bearing types All shaft diameters Tolerance h9 / IT5 General applications class 2 h10/ IT7 Transmission shafts, etc. 1 Standards for light loads, normal loads, and heavy loads Light loads: equivalent radial load 0.06Cr Normal loads: 0.06Cr equivalent radial load 0.12Cr Heavy loads: 0.12 Cr equivalent radial load 2 IT5 and IT7 show shaft roundness tolerances, cylindricity tolerances, and related values. Note: All values and fits listed in the above tables are for solid steel shafts. A-49
Page 1 and 2: For New Technology Network R corpor
Page 3 and 4: Warranty NTN warrants, to the origi
Page 5 and 6: TECHNICAL DATA CONTENTS 1. Classifi
Page 7 and 8: Classification and Characteristics
Page 13 and 14: Bearing Selection Select bearing’
Page 15 and 16: Bearing Selection 2.3 Selection of
Page 17 and 18: Load Rating and Life 3. Load Rating
Page 19 and 20: Load Rating and Life where, Lna : A
Page 21 and 22: Bearing Load Calculation 4. Bearing
Page 23 and 24: Bearing Load Calculation 4.1.2 Chai
Page 25 and 26: Bearing Load Calculation 4.4 Equiva
Page 27 and 28: Bearing Load Calculation 4.5 Allowa
Page 29 and 30: Bearing Load Calculation Fr2 70 K
Page 31 and 32: Boundary Dimensions and Bearing Num
Page 33: Boundary Dimensions and Bearing Num
Page 36 and 37: Bearing Tolerances Table 6.3 Tolera
Page 46 and 47: Bearing Tolerances 6.2 Chamfer meas
Page 48 and 49: Bearing Tolerances 6.3 Bearing tole
Page 52 and 53: Bearing Fits Table 7.2 (3) Housing
Page 54 and 55: Bearing Fits Table 7.5 Numeric valu
Page 56 and 57: Bearing Fits Table 7.6 Fits for inc
Page 58 and 59: Bearing Internal Clearance and Prel
Page 70 and 71: Allowable Speed 9. Allowable Speed
Page 72 and 73: Lubrication 11. Lubrication 11.1 Lu
Page 74 and 75: Lubrication (1) Base oil Natural mi
Page 76 and 77: Lubrication 11.4 Solid grease (For
Page 78 and 79: Lubrication Bearing operating Lubri
Page 80 and 81: External bearing sealing devices 12
Page 82 and 83: External bearing sealing devices Ty
Page 84 and 85: Bearing Materials 13.2 Cage materia
Page 86 and 87: Shaft and Housing Design 14.2 Beari
Page 88 and 89: Bearing Handling 15. Bearing Handli
Page 90 and 91: Bearing Handling a) Installation on
Page 92 and 93: Bearing Handling 15.4 Post installa
Page 94 and 95: Bearing Handling Fig. 15.24 shows t
Page 96 and 97: Bearing Damage and Corrective Measu
Page 98 and 99: Technical Data Axial displacement m
Page 100 and 101:
Technical Data 17.4 Fitting surface
Page 102 and 103:
A-100
Page 104 and 105:
INDEX OF BEARING TABLES Deep Groove
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Deep Groove Ball Bearings Open type
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Deep Groove Ball Bearings bearing i
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Deep Groove Ball Bearings D D1 rN r
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Page 121 and 122:
Page 123 and 124:
Deep Groove Ball Bearings Equivalen
Page 125 and 126:
Page 127 and 128:
Page 129:
Expansion Compensating Bearings Da
Page 132 and 133:
Miniature and Extra Small Bearings
Page 134 and 135:
Miniature and Extra Small Ball Bear
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 143 and 144:
Angular Contact Ball Bearings Angul
Page 145 and 146:
Angular Contact Ball Bearings 2. St
Page 147 and 148:
Single and Duplex Arrangements Db r
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Page 155 and 156:
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High Speed Single and Duplex Arrang
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Ultra-High Speed Angular Contact Ba
Page 169 and 170:
B-67
Page 171 and 172:
Ceramic Ball Angular Contact Ball B
Page 173 and 174:
Four-Point Contact Ball Bearings QJ
Page 175 and 176:
Double Row Angular Contact Ball Bea
Page 177:
Double Row Angular Contact Ball Bea
Page 180 and 181:
Self-Aligning Ball Bearings B r ra
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Page 184 and 185:
Page 186 and 187:
Adapters (for self-aligning ball be
Page 188 and 189:
Adapters (for self-aligning ball be
Page 191 and 192:
Cylindrical Roller Bearings Cylindr
Page 193 and 194:
Cylindrical Roller Bearings 2. Stan
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Cylindrical Roller Bearings ra r1a
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Page 207 and 208:
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L Type Loose Rib B2 B2 r1 r1 B1 d d
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L Type Loose Rib B2 B2 r1 r1 B1 d d
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Multi-Row Cylindrical Roller Bearin
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Page 221 and 222:
Page 223 and 224:
Four-Row Cylindrical Roller Bearing
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Page 227 and 228:
Page 229 and 230:
Page 231:
Page 234 and 235:
Tapered Roller Bearings Table 1 (co
Page 236 and 237:
Tapered Roller Bearings Inch Tapere
Page 238 and 239:
Tapered Roller Bearings Inch Tapere
Page 240 and 241:
Tapered Roller Bearings Metric syst
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Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Tapered Roller Bearings Inch system
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Multi-Row Tapered Roller Bearings O
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Multi-Row Tapered Roller Bearings I
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Multi-Row Tapered Roller Bearings I
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Four Row Tapered Roller Bearings C2
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Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Page 331 and 332:
Spherical Roller Bearings 1. Types,
Page 333 and 334:
Spherical Roller Bearings 5. Adapte
Page 335 and 336:
Spherical Roller Bearings ra Da ra
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Page 353 and 354:
Page 355 and 356:
Adapter (For spherical roller beari
Page 357 and 358:
Adapter (For spherical roller beari
Page 359 and 360:
Withdrawal Sleeves (For spherical r
Page 361 and 362:
Page 363 and 364:
Page 365 and 366:
Page 367 and 368:
Double Row Angular Contact Thrust B
Page 369 and 370:
Double Row Angular Contact Thrust B
Page 371 and 372:
High Speed Duplex Angular Contact T
Page 373 and 374:
High Speed Duplex Angular Contact T
Page 375 and 376:
Self-Aligning Roller Thrust Bearing
Page 377 and 378:
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Page 381 and 382:
Locknuts, Lockwashers & Lockplates
Page 383 and 384:
Locknuts Reference withdrawal sleev
Page 385 and 386:
Locknuts Reference bore no. 3 locko
Page 387 and 388:
Nuts Reference withdrawal sleeve no
Page 390 and 391:
Lockwashers Series AW ƒ r2 B2 ƒ1
Page 392 and 393:
Lockwashers Series AWL ƒ r2 B2 ƒ
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Catalog List & Appendix Table
Page 396 and 397:
Catalog List CATALOG TITLES CATALOG
Page 398:
Appendix Table SI-customary unit co
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