Machine type |
Crank driven 4-ball bush life test rig |
Motor |
φ3-4p-1.5kw |
Frequency |
0~80Hz |
 |
 |
 |
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|
Table 1 test piece properties |
lt |
Carriage raceway length,mm |
38 |
St |
Stroke,mm |
200 |
Da |
Ball diameter,mm |
3.969 |
J |
Number of ball circulations |
6 |
Zt |
Number of effective balls |
10 |
Cb |
Hertz constant, N/mm3/2 |
7.54×104 |
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|
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Table 2 Test condition |
Stroke, mm |
200 |
Test speed, km/h |
1.8 |
Test load, kN |
2.3 |
Lubricant |
Grease lub(IDEMITSU SRNo2) |
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|
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Table 3 Parameters of log-normal |
Load,kN |
2.3 |
Without prosessing |
With processing |
μ |
0.6 |
2.16 |
σ |
1.03 |
0.88 |
TM=σ/μ |
0.58 |
2.45 |
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|
|
Table 4 Parameters of 2-parameter Weibull |
Load,kN |
2.3 |
Without prosessing |
With processing |
m |
1.18 |
1.37 |
η |
265 |
1199 |
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|
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Table 5 Parameter of 3-parameter Weibull |
Load,kN |
2.3 |
Without prosessing |
With processing |
m |
10/9 |
η |
265 |
1199 |
γ |
10 |
122 |
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|
|
 |
Fig. 1 Weibull and Log-normal plot for ball bush fatigue life date without processing |
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|
 |
Fig. 2 Weibull and Log-normal plot for ball bush fatigue life date with processing |
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Table 6 Estimation from experimental data |
|
Without
Procesiing |
With
Processing |
L-N |
μ |
0.60 |
2.16 |
σ |
1.03 |
0.88 |
2PW |
m |
1.18 |
1.37 |
η |
265 |
1199 |
L10 |
43 |
245 |
L50 |
212 |
951 |
3PW |
γ |
10 |
122 |
L10 |
45 |
280 |
L50 |
200 |
984 |
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|
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Table7 Basic dynamic load ratings |
Basic dynamic
load rating |
Theory |
Without
Processing |
With
Processing |
Cth,Cex (2parameter) |
2678N |
1762N |
3100N |
Cth,Cex (3parameter) |
1621N |
2706N |
Cex/Cth
(2parameter) |
1 |
0.658 |
1.158 |
Cex/Cth
(3parameter) |
0.605 |
1.010 |
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|
 |
Fig. 3 Flaking of outer sleeve raceway surface (edge) |
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 |
Fig. 4 Flaking of outer sleeve raceway surface (straight) |