1) Write a MATLAB function that will use load ratings for 6300 series ball bearings and the AFBMA equivalent load formula to compute L10 bearing life. Attach
hardcopy of your main program and function.
The input to your function should be a vector [ BearingNumber Fr Fa ]. BearingNumber should be a value from 6300 through 6320. Variables Fr and Fa should be radial
and axial force on the bearing with units lbf. Use MATLAB “interp1” with linear interpolation and extrapolation to determine load factors X and Y with V = 1. Use
code provided on the next page for tables.n
2) To validate your function, provide plots of log(L10) for each bearing number as shown below. Validate two cases: a) Fr = 1449 lbf, Fa = 0 and b) Fr = 1449 lbf,
Fa = 1310 lbf. Attach hardcopy of your validation plot.
3) Use your function to select the smallest bearing that can provide minimum L10 life of 100×106 revolutions with Fr = 2000 lbf and Fa = 1500 lbf applied and the
inner race rotating. Specify expected L10 life, bearing bore, outside diameter and axial width with units mm.
brg number ________ L10 _________ bore _________ OD _________ width _________
% Figure 11-23 Norton *********************
% Bearing C Dynamic C0 Static
% Number Load Rating Load Rating
% [lbf] [lbf]
rating = [ 6300 1400 850 ;
6301 1700 1040 ;
6302 1930 1200 ;
6303 2320 1460 ;
6304 3000 1930 ;
6305 3800 2550 ;
6306 5000 3400 ;
6307 5700 4000 ;
6308 7350 5300 ;
6309 9150 6700 ;
6310 10600 8150 ;
6311 12900 10000 ;
6312 14000 10800 ;
6313 16000 12500 ;
6314 18000 14000 ;
6315 19300 16300 ;
6316 21200 18000 ;
6317 21600 18600 ;
6318 23200 20000 ;
6319 24500 22400 ;
6320 28500 27000 ];
% Figure 11-24 Norton **********
% Fa/C0 Y e
factors = [ 0.014 2.30 0.19 ;
0.028 1.99 0.22 ;
0.056 1.71 0.26 ;
0.084 1.55 0.28 ;
0.11 1.45 0.30 ;
0.17 1.31 0.34 ;
0.28 1.15 0.38 ;
0.42 1.04 0.42 ;
0.56 1.00 0.44 ];
