LARGE SIZE BALL & ROLLER BEARINGS LARGE SIZE BALL & ROLLER BEARINGS General Bearings CAT. NO. B2002E-1 Pr inted in Japan '12.0 8 - 5BDS ( ' 0 8.7) CAT. NO. B2002E-1 CAT. NO. B2002E-1

1 Selection of bearing dimensions ⋅⋅⋅ 4 3 Bearing fits ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 31 5 Lubrication ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 52 2 Bearing tolerances ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 13 4 Internal clearance ⋅⋅⋅⋅⋅⋅⋅⋅ 43 7 Examples of failures ⋅⋅⋅⋅ 66 6 Bearing materials ⋅⋅⋅⋅⋅⋅⋅⋅ 62 Technical data Deep groove ball 68, 69, 160, 62 ,63, SB⋅⋅⋅, 3⋅⋅⋅ bearings 78, 79, 70, 72, 73 AC⋅⋅⋅ bearings DF DB 18, 28, 38, 19, 29, 10, 30, 31, 2, 22, 32, 3, 23, 33 NU (NJ) (NUP) Angular contact ball 2AC⋅⋅⋅ 3⋅⋅⋅ (N) NN (NF) DC48(V), 49(V) FC⋅⋅⋅, 3⋅⋅⋅, 4CR⋅⋅⋅ 48, 39, 49, 30, 40, 31, FC⋅⋅⋅, 3⋅⋅⋅ Cylindrical roller 99⋅⋅⋅, D99⋅⋅⋅, T99⋅⋅⋅ bearings...

LARGE SIZE BALL & ROLLER Value & Technology

1. Selection of bearing dimensions 1-1 Bearing service life When bearings rotate under load, material flakes from the surfaces of inner and outer rings or rolling elements by fatigue arising from repeated contact stress. This phenomenon is called flaking. The total number of bearing rotations until flaking occurs is regarded as the bearing "(fatigue) service life". "(Fatigue) service life" differs greatly depending upon bearing structures, dimensions, materials, and processing methods. Since this phenomenon results from fatigue distribution in bearing materials themselves, differences in bearing...

1. Selection of bearing dimensions 1-2-3 Correction of basic dynamic load rating for high temperature use and dimension stabilizing treatment In high temperature operation, bearing material hardness deteriorates, as material compositions are altered. As a result, the basic dynamic load rating is diminished. Once altered, material composition is not recovered, even if operating temperatures return to normal. Therefore, for bearings used in high temperature operation, the basic dynamic load rating should be corrected by multiplying the basic dynamic load rating values specified in the bearing specification...

1. Selection of bearing dimensions 1-4 Dynamic equivalent load Bearings are used under various operating conditions; however, in most cases, bearings receive radial and axial load combined, while the load magnitude fluctuates during operation. Therefore, it is impossible to directly compare the actual load and basic dynamic load rating. The two are compared by replacing the loads applied to the shaft center with one of a constant magnitude and in a specific direction, that yields the same bearing service life as under actual load and rotational speed. This theoretical load is referred to as the...

1. Selection of bearing dimensions 1-4-2 Mean dynamic equivalent load When load magnitude or direction varies, it is necessary to calculate the mean dynamic equivalent load, which provides the same length of bearing service life as that under the actual load fluctuation. The mean dynamic equivalent load (Pm) under different load fluctuations is described using Graphs (1) to (4). (1) Staged fluctuation P (2) Stageless fluctuation P P1 P2 Pm Pm Pn 0 0 n1t1 p Pm = n2t2 Pmin Σ niti nntn P1p n1t1 + P2p n2t2 + ⋅⋅⋅ + Pnp nntn ⋅⋅⋅⋅⋅⋅⋅⋅⋅ (1-12) n1t1 + n2t2 + ⋅⋅⋅⋅⋅⋅ + nntn (3) Fluctuation forming sine...

1. Selection of bearing dimensions 2. Bearing tolerances 1-5-3 Safety coefficient The allowable static equivalent load for a bearing is determined by the basic static load rating of the bearing; however, bearing service life, which is affected by permanent deformation, differs in accordance with the performance required of the bearing and operating conditions. Therefore, a safety coefficient is designated, based on empirical data, so as to ensure safety in relation to basic static load rating. fs = Table 1-6 Values of safety coefficient fs Table 2-1 When high running accuracy is required With...

2. Bearing tolerances Tolerances for inch series tapered roller bearings = ABMA 19 = Table 2-5 Unit : μm (1) Inner ring Applied bearing type Nominal bore diameter d , mm (1/25.4) over up to Deviation of a single bore diameter 3 ds Class 4 Class 2 Class 3 Class 0 upper lower upper lower upper lower upper lower 76.2 ( 3.0) − + 13 0 +13 0 +13 0 +13 0 76.2 ( 3.0) 266.7 (10.5) + 25 0 +25 0 +13 0 +13 304.8 (12.0) + 25 0 +25 0 +13 0 +13 609.6 (24.0) + 51 0 +51 0 +25 0 − − 914.4 (36.0) + 76 0 − − +38 0 − 1 219.2 (48.0) +102 0 − − +51 0 − − − +127 0 − − +76 0 − Class 4 Class 2 − upper lower upper Class...

2. Bearing tolerances Table 2-6 Tolerances for metric J series tapered roller bearings1) Unit : μm (1) Bore diameter and width of inner ring and assembled bearing width Nominal bore diameter d mm over Deviation of a single bore diameter Deviation of a single inner ring width 3 ds 3 Bs Nominal bore diameter Deviation of the actual bearing width 3 Ts Class PK Class PN Class PC Class PB Class PK Class PN Class PC Class PB up to upper lower upper lower upper lower upper lower upper lower upper lower upper lower upper lower Class PK Class PN Class PC d mm Class PB upper lower upper lower upper lower...

2. Bearing tolerances Table 2-7 Tolerances for thrust ball bearings = JIS B 1514 = Table 2-8 Nominal bore diameter d mm Single plane bore diameter variation Single plane mean bore diameter deviation 3 dmp Washer raceway to back face thickness variation Deviation of the actual bearing height classes 0, 6, 5 class 0 class 6 class 5 classes 0, 6, 5 over up to −150 80 5 0 0 −175 10 5 0 25 13 7 30 30 15 7 − 45 34 30 18 9 0 − 50 38 35 21 11 800 0 − 75 55 40 25 13 800 1 000 0 −100 75 45 30 1 000 1 250 0 −125 95 50 35 80 max. upper lower 120 0 − 20 15 +200 −200 120 180 0 − 25 19 +250 −250 −200 180 250...