Design and Analysis of a Novel Power-Split Infinitely Variable Power Transmission System

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Ender İnce ◽  
Mehmet A. Güler
Keyword(s):  
Power Flow ◽  
Power Transmission ◽  
Mechanical Efficiency ◽  
Flow Equations ◽  
Power Split ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Variable Power ◽  
New System ◽  
Agricultural Machines

In the last few decades, power-split infinitely variable transmission (IVT) systems have attracted considerable attention as they ensure high driving comfort with high total efficiencies, especially in off-highway vehicles and agricultural machines. In this study, a novel power-split-input-coupled IVT system is developed. The effects of various dynamic parameters such as power flow and Willis transmission ratio on the mechanical efficiency of the systems are investigated. Kinematic analysis of the new system has been carried out. In addition power flow equations are derived as functions of the power that flows through the infinitely variable unit (IVU). The results indicate that the main parameters, which are strictly related to mechanical efficiency are the power and torque flows through the IVU.

Design Optimization of Input and Output Coupled Power Split Infinitely Variable Transmissions

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
S. Schembri Volpe ◽  
G. Carbone ◽  
M. Napolitano ◽  
E. Sedoni
Keyword(s):  
A Priori ◽  
Optimization Procedure ◽  
Mechanical Efficiency ◽  
Vehicle Speed ◽  
Mixed Solution ◽  
Input And Output ◽  
Power Split ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Coupled Solution

The authors present an optimization procedure in designing infinitely variable transmission architectures, which allows them to achieve a significant reduction in power recirculation and, hence, an increase in mechanical efficiency. The focus of this paper is on infinitely variable transmissions used in off-highway vehicles and, in particular, on input and output coupled architectures. The optimized solutions have been analyzed in depth, with particular attention to the power flowing through the infinitely variable unit, which strongly influences the overall efficiency of the transmission. The major result of this study is that the so far neglected output coupled solution, if properly optimized, guarantees very good performance over the entire range of vehicle speed. The analysis then shows that the particular choice of either input or output coupled architecture by itself, or of a mixed solution, strictly depends on the specific application under consideration and that none of them should be discarded a priori.

Modeling Hybrid Hydro-Electro-Mechanical Power-Split Propulsion Systems

2021 ◽  
Author(s):  
John R. Haughery ◽  
Brian L. Steward ◽  
Saxon J. Ryan ◽  
R. Gallolu Kankanamalage
Keyword(s):  
System Integration ◽  
Power Flow ◽  
Power Transmission ◽  
Modeling Language ◽  
Development Environment ◽  
Modeling Methodology ◽  
Power Split ◽  
Coupling Techniques ◽  
Complementary Nature ◽  
Full Power

Abstract Hydrostatic and hydro-mechanical transmissions (HSTs and HMTs, respectively) are commonly used in off-highway vehicles. While both transmission technologies can provide continuously variable torque or speed ratios, they suffer from poor efficiencies and limited operating ranges. Electric variable transmissions (EVTs), in contrast, offer complementary strengths via higher efficiencies at low forward and reverse speeds, full torque from zero to full power, and increased control capabilities. While HST, HMT, and EVT powertrain architectures are not novel, the authors are not aware of work integrating these technologies into hydro-electro-mechanical (HEMT) transmission architectures. Thus, this research aimed to develop a physical modeling methodology to explore different power-split transmission technologies using hydraulic, electrical, and mechanical pathways to understand how the complementary nature of the technologies could be used for overall power transmission performance. Steady-state modeling was performed using the Modelica® (Modelica Association) modeling language in the Dymola (Dassault Systems®) integrated development environment. Overall efficiency vs. output speed was presented for HMT, EMT, and HEMT input-coupled architectures, including circulating power considerations. This research extends the state-of-the-art of off-road powertrain technologies by providing the literature an exemplar modeling of HEMT coupling techniques, system integration, and power flow architectures in Modelica® modeling language.

Infinitely Variable Transmission of Racheting Drive Type Based on One-Way Clutches

2004 ◽  
Vol 126 (4) ◽  
pp. 673-682 ◽  
Author(s):  
F. G. Benitez ◽  
J. M. Madrigal ◽  
J. M. del Castillo
Keyword(s):  
Numerical Simulation ◽  
Dynamic Analysis ◽  
Numerical Simulations ◽  
Mechanical Efficiency ◽  
Testing Equipment ◽  
Epicyclic Gear ◽  
The Family ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Oscillatory Character

An infinitely variable transmission (IVT), based on the use of one-way action clutches, belonging to the family of ratcheting drives is described. The mechanical foundations and numerical simulations carried out along this research envisage a plausible approach to its use as gear-box in general mechanical industry and its prospective use in automobiles and self-propelled vehicles. The system includes one-way clutches—free wheels or overrunning clutches—and two epicyclic gear systems. The output velocity, with oscillatory character, common to the ratcheting drives systems, presents a period similar to that produced by alternative combustion motors, making this transmission compatible with automobile applications. The variation of the transmission is linear in all the working range. The kinematics operating principles behind this IVT is described followed by a numerical simulation of the dynamic analysis. A prototype has been constructed and tested to assess its mechanical efficiency for different reduction ratios. The efficiency values predicted by theory agree with those experimentally obtained on a bench-rig testing equipment.

Power split continuously variable transmission systems with high efficiency

2001 ◽  
Vol 215 (3) ◽  
pp. 357-358 ◽  
Author(s):  
G. Mantriota
Keyword(s):  
Power Flow ◽  
High Efficiency ◽  
Continuously Variable Transmission ◽  
Operating Conditions ◽  
Kinetic Characteristics ◽  
The Past ◽  
Power Split ◽  
Continuously Variable Transmissions ◽  
Variable Transmission ◽  
Functional Solution

Continuously variable transmissions (CVTs) have developed notably in different applications over the past years. This is especially true in the automobile field because of advantages in terms of car handling and efficiency on urban roads. In this work an original functional solution of a power split CVT system is described. The proposed solution allows the generation of a power flow without recirculation. Kinetic characteristics of single-component devices are obtained and the power split CVT system's efficiency is determined by considering how the efficiency of the component devices changes as a function of operating conditions. The advantages for the power split CVT system are therefore shown in terms of power and efficiency in comparison with the single CVT.

scholarly journals Mechanical Efficiency of HMCVT under Steady-State Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Guangqing Zhang ◽  
Hengtong Zhang ◽  
Yanyan Ge ◽  
Wei Qiu ◽  
Maohua Xiao ◽  
...  
Keyword(s):  
Steady State ◽  
Mechanical System ◽  
Hydraulic System ◽  
Power Flow ◽  
Ride Comfort ◽  
Mechanical Efficiency ◽  
Gear Train ◽  
Epicyclic Gear ◽  
Physical Prototype ◽  
Variable Transmission

Hydromechanical continuously variable transmission (HMCVT) technology has been widely used due to its advantages of ride comfort and fuel economy. The relatively uniform efficiency expression of HMCVT is obtained by studying torque and transmission ratios to reveal steady-state characteristics and predict the output torque. Mathematical models of torque ratios are derived by analyzing the HMCVT system power flow and calculating the equivalent meshing power of epicyclic gear train and efficiency for the hydraulic system. The relationship between mechanical system transmission and hydraulic system parameters is established using the torque ratios, and a mechanical system demanding surface is proposed. Two numerical examples of the HMCVT system with single and dual variable units are demonstrated to establish an effective and convenient method. The method is validated through a physical prototype TA1-02 test.

scholarly journals Performance Evaluation of a Compound Power-Split CVT for Hybrid Powertrains

2021 ◽  
Vol 11 (18) ◽  
pp. 8749
Author(s):  
Giacomo Mantriota ◽  
Giulio Reina ◽  
Angelo Ugenti
Keyword(s):  
Power Flow ◽  
Planetary Gear ◽  
Continuously Variable Transmission ◽  
Operating Conditions ◽  
Design Stage ◽  
Modeling Tools ◽  
Power Split ◽  
Variable Transmission ◽  
Gear Trains ◽  
Flow Configurations

The Power-Split Continuously Variable Transmission is one of the most promising architectures for Hybrid Electric Vehicles. These systems have been introduced to improve vehicle global efficiency since they can maximize the efficiency in varying operating conditions. During the design stage, the availability of modeling tools would play a key role in achieving optimal design and control of these architectures. In this work, a compound power split device that combines an electric Continuously Variable Transmission with two planetary gear trains is analyzed. A comprehensive model is derived that allows the different power flow configurations to be evaluated given the properties of the single subcomponents of the system. The efficiency of the powertrain can be derived as well, and a numerical example is provided. The architecture studied has an efficiency that can be higher than that obtained using one single eCVT for most of the global transmission ratio range, showing that this solution could be suitable as a part of a more complex compound transmission that engages in a specific speed range.

Reversibility of Power-Split Transmissions

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
F. Bottiglione ◽  
G. Mantriota
Keyword(s):  
Kinetic Energy ◽  
Energy Recovery ◽  
Power Flow ◽  
Mechanical Efficiency ◽  
Transmission Efficiency ◽  
Short Paper ◽  
Reverse Mode ◽  
Power Split ◽  
Continuously Variable Transmissions ◽  
Ratio Spread

Recent applications of continuously variable transmissions with large ratio spread, such as mechanical Kinetic Energy Recovery Systems or recent hybrid architectures, need the transmission to be perfectly reversible. This short paper deals with the mechanical efficiency of power-split continuously variable transmissions with particular emphasis on the switching from forward to reverse power flow. Forward and reverse transmission efficiency are calculated and compared, and the conditions which make it impossible to switch to reverse mode are studied. In particular, it is suggested that, although less efficient at high transmission ratios, a forward power circulation should be preferred because it has almost the same efficiency in forward and reverse operation.

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