The paper proposes a new approach to the efficiency evaluation of any one- or multi-degree-of-freedom gear trains. The suggested approach generalizes the known procedures developed for two-degree-of-freedom gear trains. It is based on the determination of a vector whose components are the torques delivered to the shafts of the gear train. Furthermore the paper shows that, for a notable category of gear trains, such a vector can have only a finite number of directions, which implies that a limited number of experimental data suffices for estimating the efficiency at any operational condition. Examples of application of the proposed methodology are provided.

1.
Hori, K., and Kurita, Y., 1989, “Improvement in 3K Mechanical Paradox Planetary Gear Efficiency,” Proc. of the 1989 ASME Int. Power Transmission and Gearing Conference, Chicago, IL, Apr. 25–28, pp. 259–265.
2.
Jingyuan
H.
,
1990
, “
Analysis of the Regularity of the Efficiency Variation of Differential Gear Trains by Modeling Method
,”
Chinese Journal of Mechanical Engineering
, Vol.
3
, No.
1
, pp.
92
100
.
3.
Krstich
A. M.
,
1987
, “
Determination of the General Equation of the Gear Efficiency of Planetary Gear Trains
,”
International Journal of Vehicle Design
, Vol.
8
, No.
3
, pp.
365
374
.
4.
Maggiore, A., 1971, “Il rendimento dei rotismi epicicloidali a due gradi di liberta,” Atti del 1° Congresso Nazionale di Meccanica Teorica ed Applicata, Udine, Italy, June 26–30, Vol. III, Part 2, pp. 65–85.
5.
Muller, H. W., 1971, Die Umlaufgetriebe, Springer-Verlag, Berlin.
6.
Pennestri
E.
, and
Freudenstein
F.
,
1993
, “
The Mechanical Efficiency of Epicyclic Gear Trains
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
115
, No.
3
, pp.
645
651
.
7.
Townsend, D. P., 1991, Dudley’s Gear Handbook, McGraw-Hill, New York.
8.
Yu
D.
, and
Beachley
N.
,
1985
, “
On the Mechanical Efficiency of Differential Gearing
,”
ASME JOURNAL OF MECHANISMS, TRANSMISSIONS, AND AUTOMATION IN DESIGN
, Vol.
107
, No.
1
, pp.
61
67
.
9.
Yu, D., 1987, “KHV Planetary Gearing,” Gear Technology, Nov./Dec, pp. 21–23.
10.
Yu, D., 1988, “KHV Planetary Gearing—Part II,” Gear Technology, Jan./Feb., pp. 28–48.
This content is only available via PDF.