A single-row deep groove ball bearing No. 6002 is subjected to an axial thrust of 1000 N and a radial load of 2200 N. Find the expected life that 50% of the bearings will complete under this condition.
A single-row deep groove ball bearing No. 6002 is subjected to an axial thrust of 1000 N and a radial load of 2200 N. Find the expected life that 50% of the bearings will complete under this condition.
\text { Given } F_{a}=1000 N \quad F_{r}=2200 N .
Bearing = No. 6002
Step I X and Y factors
Referring to Table 15.5, the capacities of bearing No. 6002 are,
Table 15.5 Dimensions and static and dynamic load capacities of single-row deep groove ball bearings
Designation | Basic load ratings (N) |
Principal dimensions (mm) |
|||
C_{0} | C | B | D | d | |
61800 | 630 | 1480 | 5 | 19 | 10 |
6000 | 1960 | 4620 | 8 | 26 | |
6200 | 2240 | 5070 | 9 | 30 | |
6300 | 3750 | 8060 | 11 | 35 | |
61801 | 695 | 1430 | 5 | 21 | |
6001 | 2240 | 5070 | 8 | 28 | |
6201 | 3100 | 6890 | 10 | 32 | |
6301 | 4650 | 9750 | 12 | 37 | |
61802 | 815 | 1560 | 5 | 24 | 15 |
6002 | 2500 | 5590 | 9 | 32 | |
6202 | 3550 | 7800 | 11 | 35 | |
6302 | 5400 | 11400 | 13 | 42 | |
61803 | 930 | 1680 | 5 | 26 | 17 |
6003 | 2800 | 6050 | 10 | 35 | |
6202 | 4500 | 9560 | 12 | 40 | |
6303 | 6550 | 13500 | 14 | 47 | |
6403 | 11800 | 22900 | 17 | 62 | |
61804 | 1500 | 2700 | 7 | 32 | 20 |
16404 | 3400 | 7020 | 8 | 42 | |
6004 | 4500 | 9360 | 12 | 42 | |
6204 | 6200 | 12700 | 14 | 47 | |
6304 | 7800 | 15900 | 15 | 52 | |
6404 | 16600 | 30700 | 19 | 72 | |
61805 | 1960 | 3120 | 7 | 37 | 25 |
16005 | 4000 | 7610 | 8 | 47 | |
6005 | 5600 | 11200 | 12 | 47 | |
6205 | 6950 | 14000 | 15 | 52 | |
6305 | 11400 | 22500 | 17 | 62 | |
6405 | 19600 | 35800 | 21 | 80 | |
61806 | 2080 | 3120 | 7 | 42 | 30 |
16006 | 5850 | 11200 | 9 | 55 | |
6006 | 6800 | 13300 | 13 | 55 | |
6206 | 10000 | 19500 | 16 | 62 | |
6306 | 14600 | 28100 | 19 | 72 | |
6406 | 24000 | 43600 | 23 | 90 | |
61807 | 3000 | 4030 | 7 | 47 | 35 |
16007 | 6950 | 12400 | 9 | 62 | |
6007 | 8500 | 15900 | 14 | 62 | |
6207 | 13700 | 25500 | 17 | 72 | |
6307 | 18000 | 33200 | 21 | 80 | |
6407 | 31000 | 55300 | 25 | 100 | |
61808 | 3350 | 4160 | 7 | 52 | 40 |
16008 | 7800 | 13300 | 9 | 68 | |
6008 | 9300 | 16800 | 15 | 68 | |
6208 | 16600 | 30700 | 18 | 80 | |
6308 | 22400 | 41000 | 23 | 90 | |
6408 | 36500 | 63700 | 27 | 110 | |
61809 | 3800 | 6050 | 7 | 58 | 45 |
16009 | 9300 | 15600 | 10 | 75 | |
6009 | 12200 | 21200 | 16 | 75 | |
6209 | 19600 | 33200 | 19 | 85 | |
6309 | 30000 | 52700 | 25 | 100 | |
6409 | 45500 | 76100 | 29 | 120 | |
61810 | 4250 | 6240 | 7 | 65 | 50 |
16010 | 10000 | 16300 | 10 | 80 | |
6010 | 13200 | 21600 | 16 | 80 | |
6210 | 19600 | 35100 | 20 | 90 | |
6310 | 36000 | 61800 | 27 | 110 | |
6410 | 5200 | 87100 | 31 | 130 | |
61811 | 5600 | 8320 | 9 | 72 | 55 |
16011 | 12200 | 19500 | 11 | 90 | |
6011 | 17000 | 28100 | 18 | 90 | |
6211 | 25000 | 43600 | 21 | 100 | |
6311 | 41500 | 71500 | 29 | 120 | |
6411 | 63000 | 99500 | 33 | 140 | |
61812 | 6100 | 8710 | 10 | 78 | 60 |
16012 | 13200 | 19900 | 11 | 95 | |
6012 | 18300 | 29600 | 18 | 95 | |
6212 | 28000 | 47500 | 22 | 110 | |
6312 | 48000 | 81900 | 31 | 130 | |
6412 | 69500 | 108000 | 35 | 150 | |
61813 | 8300 | 11700 | 10 | 85 | 65 |
16013 | 14600 | 21200 | 11 | 100 | |
6013 | 19600 | 30700 | 18 | 100 | |
6213 | 34000 | 55900 | 23 | 120 | |
6313 | 56000 | 92300 | 33 | 140 | |
6413 | 78000 | 119000 | 37 | 160 | |
61814 | 9150 | 12100 | 10 | 90 | 70 |
16014 | 19000 | 28100 | 13 | 110 | |
6014 | 24500 | 37700 | 20 | 110 | |
6214 | 37500 | 61800 | 24 | 125 | |
6314 | 63000 | 104000 | 35 | 150 | |
6414 | 104000 | 143000 | 42 | 180 | |
61815 | 9800 | 12500 | 10 | 95 | 75 |
10615 | 20000 | 28600 | 13 | 115 | |
6015 | 26000 | 39700 | 20 | 115 | |
6215 | 40500 | 66300 | 25 | 130 | |
6315 | 72000 | 112000 | 37 | 160 | |
6415 | 114000 | 1530000 | 45 | 190 |
\text { Also, } \quad F_{a}=1000 N \quad F_{r}=2200 N .
\left(\frac{F_{a}}{F_{r}}\right)=\left(\frac{1000}{2200}\right)=0.455 .
\text { and } \quad\left(\frac{F_{a}}{C_{o}}\right)=\left(\frac{1000}{2500}\right)=0.4 .
Referring to Table 15.4,
Table 15.4 X and Y factors for single-row deep groove ball bearings
e | \left(\frac{F_{a}}{F_{r}}\right)>e | \left(\frac{F_{a}}{F_{r}}\right) \leq e | \left(\frac{F_{a}}{C_{0}}\right) | ||
Y | X | Y | X | ||
0.22 | 2.0 | 0.56 | 0 | 1 |
0.025 |
0.24 | 1.8 | 0.56 | 0 | 1 | 0.040 |
0.27 | 1.6 | 0.56 | 0 | 1 | 0.070 |
0.31 | 1.4 | 0.56 | 0 | 1 | 0.130 |
0.37 | 1.2 | 0.56 | 0 | 1 | 0.250 |
0.44 | 1.0 | 0.56 | 0 | 1 | 0.500 |
\left(\frac{F_{a}}{F_{r}}\right)>e .
The value of Y is obtained by linear interpolation.
Y=1.2-\frac{(1.2-1.0)}{(0.5-0.25)} \times(0.4-0.25)=1.08 \text { and } .
X = 0.56
\text { Step II Bearing life }\left(L_{10}\right) .
P=X F_{r}+Y F_{a}=0.56(2200)+1.08(1000) .
= 2312 N
From Eq. (15.7),
C=P\left(L_{10}\right)^{1 / 3} (15.7).
C=P\left(L_{10}\right)^{1 / 3} \quad 5590=2312\left(L_{10}\right)^{1 / 3} .
\therefore \quad L_{10}=14.13 \text { million rev. }\text { Step III Bearing life }\left(L_{50}\right).
It can be proved that the life \left(L_{50}\right) , which 50% of the bearings will complete or exceed, is approximately five times the life \left(L_{10}\right) which 90% of the bearings will complete or exceed.
Therefore