Abstract

A hydromechanical transmission (HMT) is a continuously variable transmission that transmits power both mechanically and hydraulically. A typical HMT consists of a pair of hydraulic pump/motors and a mechanical transmission in parallel, making it bulky and costly. The Hondamatic transmission is a compact alternative HMT design that uses an inline configuration such that the rotation of the piston barrels of the pump and motor is dual-used for mechanical transmission. This is achieved using a two-shafted pump that plays the role of a planetary gear (PG) and a distributor valve mechanism that replaces the valve plates. This paper provides the operating principle of this inline HMT (iHMT) and analyzes its performance through a combination of modeling and experimentation. Specifically, ideal and lossy average models are developed, and the performance of the Hondamatic is characterized experimentally. The lossy model, fitted with seven empirically determined parameters, is capable of predicting the mechanical and volumetric losses at different ratios and operating conditions. The dominant losses are found to be compressibility losses and no-load viscous friction losses, especially on the motor side. These losses are attributed to be the main causes for the unity transmission ratio to be less efficient than expected. The overall efficiency is between 74 and 86% at the conditions tested experimentally and is predicted to be over 70% under most operating conditions and transmission ratios. This analytical and experimental study is the first study in the open literature on this innovative compact inline HMT configuration.

References

1.
Kress
, J. H.
,
1968
, “
Hydrostatic Power Splitting Transmissions for Wheeled Vehicles-Classification and Theory of Operation
,”
SAE
Paper No. 680549. 10.4271/680549
2.
Jarchow
,
F.
,
1964
, “
Leistungsverzweigte Getriebe (Power Split Transmissions)
,”
VDI-Z
,
106
(
6
), pp.
196
205
.
3.
Kohmäscher
,
T.
,
2008
, “
Modelbildung, Analyse Und Auslegung Hydrostatischer Antriebsstrangkonzepte
,” Ph.D. dissertation, RWTH Aachen, Germany.
4.
Carl
,
B.
,
Ivantysynova
,
M.
, and
Williams
,
K.
,
2006
, “
Comparison of Operational Characteristics in Power Split Continuously Variable Transmissions
,”
SAE
Paper No. 2006-01-3468. 10.4271/2006-01-3468
5.
Alarico
,
M.
, and
Rossetti
,
A.
,
2011
, “
Optimization of Hydro-Mechanical Power Split Transmissions
,”
Mech. Mach. Theory
,
46
(
12
), pp.
1901
1919
.10.1016/j.mechmachtheory.2011.07.007
6.
Du
,
Z.
,
Cheong
,
K. L.
,
Li
,
P. Y.
, and
Chase
,
T. R.
, June
2013
, “
Fuel Economy Comparisons of Series, Parallel and HMT Hydraulic Hybrid Architectures
,” Proceedings of the 2013
American Control Conference
, Washington, DC, pp.
5954
5959
.10.1109/ACC.2013.6580772
7.
Sung
,
D.
,
Hwang
,
S.
, and
Kim
,
H.
,
2005
, “
Design of Hydromechanical Transmission Using Network Analysis
,”
Proc. Inst. Mech. Eng., Part D
,
210
(
1
), pp.
53
63
.10.1243/095440705X6406
8.
Pettersson
,
K.
, and
Krus
,
P.
,
2013
, “
Design Optimization of Complex Hydromechanical Transmission
,”
ASME J. Mech. Des.
,
135
(
9
), p.
091005
.10.1115/1.4024732
9.
Rossetti
,
A.
,
Macor
,
A.
, and
Scamperle
,
M.
,
2017
, “
Optimization of Components and Layouts of Hydromechanical Transmissions
,”
Int. J. Fluid Power
,
18
(
2
), pp.
123
134
.10.1080/14399776.2017.1296746
10.
Cheong
,
K. L.
,
Li
,
P. Y.
, and
Chase
,
T. R.
,
2011
, “
Optimal Design of Power-Split Transmissions for Hydraulic Hybrid Passenger Vehicles
,”
American Control Conference
, San Francisco, CA, June 29, pp.
3295
3300
.10.1109/ACC.2011.5991509
11.
Reimer
,
L. H.
,
1972
, “
Neutral Control for Hydraulic Transmission
,” U.S. Patent No. 3,698,189.
12.
SaitouOkuzaki
,
M.
,
Kazuhiro
,
H. T.
, and
Takeuchi
,
S.
,
2006
, “
Hydraulic Continuously Variable Transmission
,” U.S. Patent No. 7,000,388 B2.
13.
Cyders
,
T. J.
,
2012
, “
Analysis and Experimental Comparison of Models of a New Form of Continuously Variable Transmission
,”
Doctoral dissertation
, Department of Mechanical Engineering, Ohio University, Athens, OH.http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1354807440
You do not currently have access to this content.