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codeproject vb.net barcode generator ROLLINGCONTACT BEARINGS 18.10 in Software
ROLLINGCONTACT BEARINGS 18.10 Decoding EAN / UCC  13 In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. EAN 13 Generator In None Using Barcode generation for Software Control to generate, create EAN13 image in Software applications. BEARINGS AND LUBRICATION
Recognizing EAN13 In None Using Barcode decoder for Software Control to read, scan read, scan image in Software applications. EAN13 Maker In C#.NET Using Barcode creation for VS .NET Control to generate, create EAN / UCC  13 image in .NET applications. FIGURE 18.13 Survival function representing endurance tests on rollingcontact bearings from data accumulated by SKF Industries, Inc. (From Ref. [18.2].) Painting EAN13 In Visual Studio .NET Using Barcode printer for ASP.NET Control to generate, create EAN13 Supplement 5 image in ASP.NET applications. Creating EAN 13 In Visual Studio .NET Using Barcode drawer for .NET Control to generate, create UPC  13 image in .NET framework applications. If LR is in hours and nR is in revolutions per minute, then L10 = 60LRnR. It follows that C10 = FD LDnD LRnR GTIN  13 Drawer In VB.NET Using Barcode generation for Visual Studio .NET Control to generate, create EAN13 image in Visual Studio .NET applications. UCC.EAN  128 Printer In None Using Barcode maker for Software Control to generate, create EAN 128 image in Software applications. (18.6) Code128 Generation In None Using Barcode generation for Software Control to generate, create Code 128 Code Set C image in Software applications. Bar Code Creation In None Using Barcode generator for Software Control to generate, create barcode image in Software applications. where the subscript D refers to desired (or design) and the subscript R refers to rating conditions.
Generating Barcode In None Using Barcode creator for Software Control to generate, create barcode image in Software applications. Encode UPC  13 In None Using Barcode encoder for Software Control to generate, create GTIN  13 image in Software applications. 18.3 SURVIVAL RELATION AT STEADY LOAD
Draw Postnet 3 Of 5 In None Using Barcode generator for Software Control to generate, create Delivery Point Barcode (DPBC) image in Software applications. Barcode Creation In ObjectiveC Using Barcode drawer for iPhone Control to generate, create bar code image in iPhone applications. Figure 18.14 shows how reliability varies as the loading is modified [18.2]. Equation (18.5) allows the ordinate to be expressed as either F/C10 or L/L10. Figure 18.14 is based on more than 2500 SKF bearings. If Figs. 18.13 and 18.14 are scaled for recovery of coordinates, then the reliability can be tabulated together with L/L10. Machinery applications use reliabilities exceeding 0.94. An excellent curve fit can be realized by using the threeparameter Weibull distribution. For this distribution the reliability can be expressed as R = exp x x0 x0 Printing UPC A In Java Using Barcode encoder for Android Control to generate, create UPCA image in Android applications. GS1128 Generation In None Using Barcode maker for Online Control to generate, create UCC  12 image in Online applications. (18.7) Bar Code Creator In Java Using Barcode drawer for Eclipse BIRT Control to generate, create bar code image in BIRT reports applications. EAN / UCC  14 Maker In .NET Using Barcode creator for Visual Studio .NET Control to generate, create EAN / UCC  14 image in .NET framework applications. where x = life measure, x0 = Weibull guaranteed life measure, = Weibull characteristic life measure, and b = Weibull shape factor. Using the 18 points in Table 18.3 with x0 = 0.02, = 4.459, and b = 1.483, we see that Eq. (18.7) can be particularized as R = exp L/L10 0.02 4.439 Decode ANSI/AIM Code 128 In VB.NET Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications. EAN / UCC  13 Encoder In ObjectiveC Using Barcode creation for iPhone Control to generate, create UPC  13 image in iPhone applications. (18.8) Downloaded from Digital Engineering Library @ McGrawHill (www.digitalengineeringlibrary.com) Copyright 2004 The McGrawHill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. ROLLINGCONTACT BEARINGS 18.11
ROLLINGCONTACT BEARINGS
FIGURE 18.14 Survival function at higher reliabilities based on more than 2500 endurance tests by SKF Industries, Inc. (From Ref. [18.2].) The threeparameter Weibull constants are = 4.459, b = 1.483, and x0 = 0.02 when x = L/L10 = Ln/(LRnR). For example, for L/L10 = 0.1, Eq. (18.8) predicts R = 0.9974.
18.4 RELATING LOAD, LIFE, AND RELIABILITY GOAL
If Eq. (18.3) is plotted on loglog coordinates, Fig. 18.15 results. The FL loci are rectified, while the parallel loci exhibit different reliabilities. The coordinates of point A are the rating life and the basic load rating. Point D represents the desired (or design) life and the corresponding load. A common problem is to select a bearing which will provide a life LD while carrying load FD and exhibit a reliability RD. Along line BD, constant reliability prevails, and Eq. (18.4) applies: TABLE 18.3 Survival Equation Points at Higher Reliabilities
Downloaded from Digital Engineering Library @ McGrawHill (www.digitalengineeringlibrary.com) Copyright 2004 The McGrawHill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. ROLLINGCONTACT BEARINGS 18.12
BEARINGS AND LUBRICATION
FIGURE 18.15 Reliability contours on a loadlife plot useful for relating catalog entry, point A, to design goal, point D. FB = FD
xD xB
(18.9) Along line AB the reliability changes, but the load is constant and Eq. (18.7) applies. Thus R = exp x x0 x0 (18.10) Now solve this equation for x and particularize it for point B, noting that RD = RB. xB = x0 + ( x0) ln Substituting Eq. (18.11) into Eq. (18.9) yields FB = C10 = FD xD x0 + ( x0)[ln (1/RD)]1/b 1 RD
(18.11) (18.12) 1 R and Eq.
For reliabilities greater than 0.90, which is the usual case, ln (1/R) (18.12) simplifies as follows: C10 = FD xD x0 + ( x0)(1 R)1/b (18.13) The desired life measure xD can be expressed most conveniently in millions of revolutions (for SKF). Example 1. If a ball bearing must carry a load of 800 lb for 50 106 and exhibit a reliability of 0.99, then the basic load rating should equal or exceed Downloaded from Digital Engineering Library @ McGrawHill (www.digitalengineeringlibrary.com) Copyright 2004 The McGrawHill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. ROLLINGCONTACT BEARINGS 18.13
ROLLINGCONTACT BEARINGS
C10 = 800 50 0.02 + (4.439)(1 0.99)1/1.483 = 4890 lb This is the same as 21.80 kN, which corresponds to the capability of a 02 series 35mmbore ball bearing. Since selected bearings have different basic load ratings from those required, a solution to Eq. (18.13) for reliability extant after specification is useful: R=1 xD x0(C10/FD)a ( x0)(C10/FD)a (18.14) Example 2. If the bearing selected for Example 1, a 02 series 50mm bore, has a basic load rating of 26.9 kN, what is the expected reliability And C10 = (26.9 103)/445 = 6045 lb. So R=1 50 0.02(6045/800)3 (4.439)(6045/800)3 = 0.9966 The previous equations can be adjusted to a twoparameter Weibull survival equation by setting x0 to zero and using appropriate values of and b. For bearings rated at a particular speed and time, substitute LDnD/(LRnR) for xD. The survival relationship for Timken taperedroller bearings is shown graphically in Fig. 18.16, and points scaled from this curve form the basis for Table 18.4. The survival equation turns out to be the twoparameter Weibull relation: R = exp x

