4。2。4 Calculation of Components of Power Loss 83

4。3 Gear Efficiency Test Results 87

CHAPTER 5: CONCLUSION 100

5。1 Summary 100

5。2 Major Conclusions 101

5。3 Recommendations for Future Work 104

REFERENCES 105

APPENDIX A:  A Sample Gear CMM Inspection Report for a Highly Polished Test Gear 110

LIST OF TABLES

Table Page

2。1 Preliminary tests performed to define a tration test duration with minimum surface roughness changes 25

2。2 Surface roughness inspection parameters utilized on the roughness inspection

machine 37

3。1 Traction test matrix 40

3。2 Computed minimum film thickness and lambda ratio values for tests with MIL-PRF- 23699 oil and 80W90 oil 41

3。3 Scuffing test matrix and summary of the test results 60

4。1 Gear design parameters of the unity-ratio test gear pair used in the efficiency study 77

4。2 Measured surface roughness values of test gears before testing 80

4。3 Test matrix used in the gear efficiency study 81

LIST OF FIGURES

Figure Page

2。1 Twin disk test machine used in this study 10

2。2 A top view schematic of two disk test machine used in this study 11

2。3 Close up view of the test pair, roller and disk shafts, roller-side flexible coupling

and the loading arm 13

2。4 Engineering drawing of the roller specimens 16

2。5 Engineering drawing of the disk specimens 17

2。6 Variation of half lengths a and b of the contact ellipse and maximum contact stress

with the normal force 18

2。7 Ground, highly polished, chemically polished and NiB coated test specimens used in

this study 20

2。8 Example measured roughness profiles for ground, chemically polished, highly

Polished, and NiB coated rollers 21

2。9 Measured Rq values of roller and disk specimens throughout the preliminary study According to Table 2。1 26

2。10