mechanical engineering project

Project 3: Ball Bearing Life Analysis Due: 12/11/15 ME 360 Section 003

Project Goal:

Your goal is to study how the L10 life of the entire 6300 ball bearing set changes as the bearing size ranges from the smallest to the largest bearing for multiple loading scenarios. In class and in a previous homework assignment, you solved for the correct bearing size using bearing tables in Figures 11-23 and 11-24 for a particular effective loading scenario and a particular L10 life. Now you must perform a study in MATLAB that solves for the entire range of L10 life values for every 6300 series ball bearing. Project Details:

You must complete the following tasks & deliverables and package them together in a final report document with a cover page that includes (Project name, all of your names, your project group number, and the due date). Task 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 the code provided on the next page for tables. Deliverables:

• Hard copy of your main program script • Hard copy of your bearing function

Task 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. Deliverable:

• Attach hard copy of your validation plot for these two loading scenarios Task 3:

Use your function to select the smallest bearing that can provide minimum L10 life of 100x10 6 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. Deliverable:

bearing number ________ L10 _________ bore _________ OD _________ width _________

Project 3: Ball Bearing Life Analysis Due: 12/11/15 ME 360 Section 003

% 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 ];

6300 6302 6304 6306 6308 6310 6312 6314 6316 6318 6320 -0.5

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ME 360 - Project 3 - HJSIII

a) Fr=1449 lbf, Fa=0 b) Fr=1449 lbf, Fa=1310 lbf