Abstract

A computational model is proposed for the prediction of friction-related mechanical efficiency losses of parallel-axis gear pairs. The model incorporates a gear load distribution model, a friction model, and a mechanical efficiency formulation to predict the instantaneous mechanical efficiency of a gear pair under typical operating, surface, and lubrication conditions. The friction model uses a new friction coefficient formula obtained by using a validated non-Newtonian thermal elastohydrodynamic lubrication (EHL) model in conjunction with a multiple linear regression analysis. The load and friction coefficient distribution predictions are used to compute instantaneous torque/power losses and the mechanical efficiency of a gear pair at any given rotational position. Efficiency measurements from gear pairs having various gear designs and surface treatments are compared to model predictions. Mechanical efficiency predictions are shown to be within 0.1% of the measured values, indicating that the proposed efficiency model is accurate. Results of a parametric study are presented at the end to highlight the influence of key basic gear geometric parameters, tooth modifications, operating conditions, surface finish, and lubricant properties on mechanical efficiency losses.

References

1.
Reuleaux
,
F.
, 1886, “
Friction in Tooth Gearing
,”
Trans. ASME
0097-6822,
VIII
, pp.
45
85
.
2.
Martin
,
K. F.
, 1978, “
A Review of Friction Predictions in Gear Teeth
,”
Wear
0043-1648,
49
,
201
238
.
3.
Yada
,
T.
, 1997, “
Review of Gear Efficiency Equation and Force Treatment
,”
JSME Int. J., Ser. C
1340-8062,
40
, pp.
1
8
.
4.
Li
,
Y.
, and
Seireg
,
A. A.
, “
Predicting the Coefficient of Friction in Sliding-Rolling Contacts
,” Tribology Conference, K18.
5.
Denny
,
C. M.
, 1998, “
Mesh Friction in Gearing
,” AGMA Fall Technical Meeting, 98FTM2.
6.
Pedrero
,
J. I.
, 1999, “
Determination of the Efficiency of Cylindrical Gear Sets
,” 4th World Congress on Gearing and Power Transmission, Paris, France.
7.
Michlin
,
Y.
, and
Myunster
,
V.
, 2002, “
Determination of Power Losses in Gear Transmissions with Rolling and Sliding Friction Incorporated
,”
Mech. Mach. Theory
0094-114X,
37
, pp.
167
174
.
8.
Benedict
,
G. H.
, and
Kelly
,
B. W.
, 1960, “
Instantaneous Coefficients of Gear Tooth Friction
,” Transactions of ASLE, ASLE Lubrication Conference,
57
70
.
9.
Kelley
,
B. W.
, and
Lemanski
,
A. J.
, 1967–1968, “
Lubrication of Involute Gearing
,”
Proc. Inst. Mech. Eng.
0020-3483,
182
, pp.
173
184
.
10.
ISO TC 60, DTR 13989.
11.
O’Donoghue
,
J. P.
, and
Cameron
,
A.
, 1966, “
Friction and Temperature in Rolling Sliding Contacts
,”
ASLE Trans.
0569-8197,
9
, pp.
186
194
.
12.
Drozdov
,
Y. N.
, and
Gavrikov
,
Y. A.
, 1967, “
Friction and Scoring Under the Conditions of Simultaneous Rolling and Sliding of Bodies
,”
Wear
0043-1648, pp.
291
302
.
13.
Misharin
,
Y. A.
, 1958, “
Influence of the Friction Condition on the Magnitude of the Friction Coefficient in the Case of Rollers With Sliding
,”
Proceedings of Int. Conference on Gearing, Inst. Mech. Eng.
, London, pp.
159
164
.
14.
Ku
,
P. M.
,
Staph
,
H. E.
, and
Carper
,
H. J.
, 1978, “
Frictional and Thermal Behaviors of Sliding Rolling Concentrated Contacts
,”
ASME J. Lubr. Technol.
0022-2305,
100
, pp.
121
128
.
15.
Naruse
,
C.
,
Haizuka
,
S.
,
Nemoto
,
R.
, and
Kurokawa
,
K.
, 1986, “
Studies on Frictional Loss, Temperature Rise and Limiting Load for Scoring of Spur Gear
,”
Bull. JSME
0021-3764,
29
, pp.
600
608
.
16.
Sasaki
,
T.
,
Okamura
,
K.
, and
Isogai
,
R.
, 1961–1963, “
Fundamental Research in Gears
,”
Bull. JSME
0021-3764,
4
, pp.
382
393
,
Sasaki
,
T.
,
Okamura
,
K.
, and
Isogai
,
R.
, 1961–1963, “
Fundamental Research in Gears
,”
Bull. JSME
0021-3764,
5
, pp.
561
569
,
Sasaki
,
T.
,
Okamura
,
K.
, and
Isogai
,
R.
, 1961–1963, “
Fundamental Research in Gears
,”
Bull. JSME
0021-3764,
6
, pp.
364
375
.
17.
Barnes
,
J. P.
, 1997, “
Non-dimensional Characterization of Gear Geometry, Mesh Loss and Windage
,” AGMA 97FTM11.
18.
Hohn
,
B. R.
, and
Steingrover
,
K.
, 1998, “
Local Coefficients of Friction in Worm Gear Contacts
,” AGMA 98FTM10.
19.
Heingartner
,
P.
, and
Mba
,
D.
, 2003, “
Determining Power Losses in The Helical Gear Mesh; Case Study
,” Proceeding of DETC’3, ASME 2003 Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Chicago, Illinois.
20.
Anderson
,
N. E.
, and
Loewenthal
,
S. H.
, 1986, “
Efficiency of Nonstandard and High Contact Ratio Involute Spur Gears
,”
ASME J. Mech., Transm., Autom. Des.
0738-0666,
108
, pp.
119
126
.
21.
Anderson
,
N. E.
, and
Loewenthal
,
S. H.
, 1982, “
Design of Spur Gears for Improved Efficiency
,”
ASME J. Mech. Des.
1050-0472,
104
, pp.
767
774
.
22.
Anderson
,
N. E.
, and
Loewenthal
,
S. H.
, 1981, “
Effect of Geometry and Operating Conditions on Spur Gear System Power Loss
,”
ASME J. Mech. Des.
1050-0472,
103
, pp.
151
159
.
23.
Vaishya
,
M.
, and
Houser
,
D. R.
, 1999, “
Modeling and Measurement of Sliding Friction for Gear Analysis
,” AGMA 99FTMS1, Lakewood, CO.
24.
Martin
,
K. F.
, 1981, “
The Efficiency of Involute Spur Gears
,”
ASME J. Mech. Des.
1050-0472,
103
, pp.
160
169
.
25.
Dowson
,
D.
, and
Higginson
,
G. R.
, 1964, “
A Theory of Involute Gear Lubrication
,”
Proceeding of a Symposium Organized by the Mechanical Tests of Lubricants Panel of the Institute
,
Institute of Petroleum
, Gear Lubrication, Elsevier, London,
8
15
.
26.
Simon
,
V.
, 1981, “
Load Capacity and Efficiency of Spur Ears in Regard to Thermo-End Lubrication
,” International Symposium on Gearing and Power Transmissions, Tokyo, Japan.
27.
Wu
,
S.
, and
Cheng
,
H. S.
, 1991, “
A Friction Model of Partial-EHL Contacts and its Application to Power Loss in Spur Gears
,”
Tribol. Trans.
1040-2004,
34
, pp.
398
407
.
28.
Mihalidis
,
A.
,
Bakolas
,
V.
,
Panagiotidis
,
K.
, and
Drivakos
,
N.
, 2002, “
Prediction of the Friction Coefficient of Spur Gear Pairs
,” VDI-Berichte, NR. 1665, pp.
705
719
.
29.
Akin
,
L. S.
, 1974, “
EHD Lubricant Film Thickness Formulae for Power Transmission Gears
,”
ASME J. Lubr. Technol.
0022-2305,
96
, pp.
426
431
.
30.
Wellauer
,
E. J.
, and
Holloway
,
S. H.
, 1976, “
Application of EHD Oil Film Theory to Industrial Gear Drives
,”
ASME J. Eng. Ind.
0022-0817, Series B,
98
, pp.
626
634
.
31.
Chittenden
,
R. J.
,
Dowson
,
D.
,
Dunn
,
J. F.
, and
Taylor
,
C. M.
, 1985, “
A Theoretical Analysis of The Isothermal Elastohydrodynamic Lubricant of Concentrated Contacts
,”
Proc. R. Soc. London, Ser. A
1364-5021,
397
, pp.
271
294
.
32.
Simon
,
V.
, 1988, “
Thermo-EHD Analysis of Lubrication of Helical Gears
,”
ASME J. Mech. Des.
1050-0472,
110
, pp.
330
336
.
33.
Haizuka
,
S.
,
Naruse
,
C.
, and
Yamanaka
,
T.
, 1999, “
Study of Influence of Helix Angle on Friction Characteristics of Helical Gears
,”
Tribol. Trans.
1040-2004,
42
(
3
), pp.
570
580
.
34.
Khonsari
,
M. M.
, and
Booser
,
E. R.
, 2001,
Applied Tribology, Bearing Design and Lubrication
,
Wiley
, New York.
35.
Conry
,
T. F.
, and
Seireg
,
A.
, 1973, “
A Mathematical Programming Technique for the Evaluation of Load Distribution and Optimal Modifications for Gear Systems
,”
ASME J. Eng. Ind.
0022-0817,
95
, pp.
1115
1122
.
36.
LDP, Gear Load Distribution Program, 2003, Gear Dynamics and Gear Noise Research Laboratory, The Ohio State University, Columbus, Ohio, USA.
37.
Dudley
,
D. W.
, 1994,
Handbook of Practical Gear Design
,
CRC
, Cleveland.
38.
Colbourne
,
J. R.
, 1987,
The Geometry of Involute Gears
,
Springer-Verlag
, New York.
39.
Litvin
,
F. L.
, 1994,
Gear Geometry and Applied Theory
,
Prentice Hall
, Englewood Cliffs, New Jersey.
40.
Xu
,
H.
, 2005, “
Development of a Generalized Mechanical Efficiency Prediction Methodology for Gear Pairs
,” Ph.D. Dissertation, Ohio State University, Columbus, Ohio.
41.
Cioc
,
C.
,
Cioc
,
S.
,
Moraru
,
L.
,
Kahraman
,
A.
, and
Keith
,
T.
, 2002, “
A Deterministic Elastohydrodynamic Lubrication Model of High-Speed Rotorcraft Transmission Components
,”
Tribol. Trans.
1040-2004,
45
, pp.
556
562
.
42.
Dowson
,
D.
, and
Higginson
,
G. R.
, 1977,
Elasto-hydrodynamic Lubrication
, SI ed.,
Pergamon Press
, Oxford, England.
43.
Chase
,
D.
, 2005, “
The Development of an Efficiency Test Methodology for High-Speed Gearbox
,” MS thesis, The Ohio State University, Columbus, Ohio.
44.
Johnson
,
K. L.
, and
Cameron
,
R.
, 1967–68, “
Shear Behavior of Elastohydrodynamic Oil Films at High Rolling Contact Pressures
,”
Proc. Inst. Mech. Eng.
0020-3483,
182
(
14
), pp.
307
319
.
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