scholarly journals Power Split Based Dual Hemispherical Continuously Variable Transmission

Actuators ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 15 ◽  
Author(s):  
Douwe Dresscher ◽  
Mark Naves ◽  
Theo de Vries ◽  
Martijn Buijze ◽  
Stefano Stramigioli
Keyword(s):  
Continuously Variable Transmission ◽  
Power Split ◽  
Variable Transmission

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 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.

scholarly journals Effects of Electric Circulation on the Energy Efficiency of the Power Split e-CVT Hybrid Systems

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2342 ◽  
Author(s):  
Cheng-Ta Chung ◽  
Chien-Hsun Wu ◽  
Yi-Hsuan Hung
Keyword(s):  
Energy Efficiency ◽  
Hybrid Systems ◽  
High Speed ◽  
Electric Energy ◽  
Continuously Variable Transmission ◽  
Operating Characteristics ◽  
Power Split ◽  
Variable Transmission ◽  
And Control ◽  
Operating Points

This paper aims at investigating the fundamental characteristics of energy efficiency for power split electronic-continuously-variable-transmission (e-CVT) hybrid systems under the operation of electric circulation, i.e., circulating part of the engine power through the generator and motor in form of electric energy to improve system efficiency as well as perform the continuously-variable-transmission (CVT) functionality. The relations of kinematics and energy conservation for each power component are constructed and analyzed to classify how the operating points of the engine in term of torque and rotational speed may vary under different degrees of electric circulation indicated by a parameter called ratio of circulating power. Thereby, power split e-CVT hybrid systems can be classified into three types: upward circulation, downward circulation, and neutral circulation. Accordingly, two power split e-CVT hybrid systems, one of input split type and the other of output split type, are selected to be analyzed regarding their operating characteristics and simulated on their performances of energy efficiency. As a result, the former is a type of downward circulation in favor of driving at low speed and high driving load, while the latter is a type of upward circulation with an advantage of driving at high speed and low driving load. Thereby, applying this analysis to investigate the effects of electric circulation on power split e-CVT systems may help the developers implement suitable energy management and control strategy in accordance with their corresponding operating characteristics of energy efficiency.

On the design and tuning of the controllers in a power-split continuously variable transmission for agricultural tractors

2003 ◽  
Vol 217 (8) ◽  
pp. 745-759 ◽  
Author(s):  
S M Savaresi ◽  
F Taroni ◽  
F Prevedi ◽  
S Bittanti
Keyword(s):  
High Efficiency ◽  
Continuously Variable Transmission ◽  
System Structure ◽  
Transmission Ratio ◽  
Mechanical Transmission ◽  
Power Split ◽  
Variable Transmission ◽  
Servo Controller ◽  
Automatic Controllers ◽  
Agricultural Tractors

In this work, a power-split continuously variable transmission (CVT) used in high-power tractors is considered. Power-split CVTs are characterized by the combination of a traditional discontinuous mechanical transmission and a continuously variable transmission. This provides, at the same time, smooth variations of the transmission ratio and high efficiency of the overall transmission system. The CVT considered in this paper is a hydrostatic power-split unit conceived for top-power agricultural tractors. The goal of this paper is to present a case study on the design and tuning of the control system structure for this type of CVT. This structure consists of three main parts: a servo controller on the internal current of the valve of the hydraulic transmission; a servo controller on the hydraulic transmission ratio; a synchronizer which coordinates the hydraulic and the mechanical parts of the CVT. The design, tuning and testing of this set of automatic controllers is presented.

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