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.

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.

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.

Dynamic Analysis of a Novel Geared Infinitely Variable Transmission

2014 ◽  
Author(s):  
Z. R. Li ◽  
X. F. Wang ◽  
W. D. Zhu
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Speed Ratio ◽  
Lagrangian Dynamics ◽  
Input And Output ◽  
Newtonian Dynamics ◽  
Continuous Output ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Crank Length

A novel geared infinitely variable transmission (IVT) that can generate a continuous output-to-input speed ratio from zero to a certain value is studied for vehicle and wind turbine applications. The principle of changing the output-to-input speed ratio is to use a crank-slider mechanism; the output-to-input speed ratio is controlled by adjusting the crank length. Since the crank-slider mechanism can lead to relatively large variation of the output-to-input speed ratio in one rotation of the crank, the instantaneous input and output speeds and accelerations have variations and the corresponding forces exerted on each part of the IVT can have obvious changes in one rotation of the crank. Since forces on some parts of the IVT are critical and can cause failure of the IVT, a dynamic analysis of the IVT is necessary to simulate the input and output speeds and accelerations. A method that combines Lagrangian dynamics and Newtonian dynamics is developed in this work to analyze the motion of the IVT. The dynamic analysis results can be used to evaluate the design of the IVT.

DC Motor Selection for Hybrid and Electric Vehicles Using an Infinitely Variable Transmission

2011 ◽  
Author(s):  
Benjamin C. Groen ◽  
Robert H. Todd
Keyword(s):  
Control Method ◽  
Low Cost ◽  
Speed Control ◽  
Dc Motor ◽  
Limited Range ◽  
Operating Voltage ◽  
Vehicle Speed ◽  
Battery Management ◽  
Variable Transmission ◽  
Infinitely Variable Transmission

Demand for more fuel efficient and less polluting vehicles has motivated development of the electric and hybrid power-trains. Unfortunately, some components used in these vehicles are expensive and complex. This research summarizes DC motor types, DC speed control methods and the use of an Infinitely Variable Transmission (IVT) to reduce the cost of the vehicle. A safe, low cost and repeatable laboratory setup was designed and documented for educational use. Motor testing revealed that field weakening can be a low-cost speed-control method but has limited range of control and must be supplemented. Additionally it was determined that a mechanical differential can be used as an IVT by varying the speed of the input motors. An innovative concept is presented using one DC motor as a power or traction motor, while another motor acts as a vehicle speed controller. This concept eliminates the need for expensive complex AC motor controllers, improves safety and efficiency, and reduces battery management requirements by lowering the operating voltage of the system.

A Study on the Contact Behaviors of Infinitely Variable Transmission System with Full Toroidal Shapes of Disks

2005 ◽  
Vol 297-300 ◽  
pp. 351-356
Author(s):  
Si Youl Jang ◽  
Wan Choi
Keyword(s):  
Contact Area ◽  
Applied Load ◽  
High Stress ◽  
Rolling Direction ◽  
Transmission System ◽  
Assembly Design ◽  
Contact Points ◽  
Input And Output ◽  
Variable Transmission ◽  
Infinitely Variable Transmission

The torque of the continuously variable transmission system with friction drive mechanism is transmitted by contacting roller with input and output disks. For the higher transmitted torque, it is necessary to apply large load in order to get higher friction force, which in turn generates severe high stress on the contact surfaces of roller and disks. The toroidal type CVT system has simple component arrays that have three contact points between roller and each input or output disk to get the torque transmitted. However, compact assembly design of the three sets of rollers contacting with input and output disks needs the roller to stay with unsymmetrical angled position with each other. Therefore, the contact shapes between roller and disk vary according to the transmission ratio and should be investigated to avoid the excessive contact stress over than ~1.8 GPa. In this study, the contact geometries of roller and disks in the toroidal type CVT system are computed during the gear ratios. The contact area of which the size depends on the material elasticity, curvatures of roller and disk, and applied load are all of elliptic shapes because of the convex and concave curvatures of roller and disk shapes, respectively. From the computed results considering the size of roller diameter, roller stroke and applied load, it is found that the shapes of contact area changes the sizes of major and minor elliptical diameters in the rolling direction during the gear ratios due to the unsymmetrical angled position of roller.

scholarly journals Machine Learning Guided Approach for Studying Solvation Environments

2019 ◽  
Author(s):  
Yasemin Basdogan ◽  
Mitchell C. Groenenboom ◽  
Ethan Henderson ◽  
Sandip De ◽  
Susan Rempe ◽  
...  
Keyword(s):  
A Priori ◽  
Optimization Procedure ◽  
Low Energy ◽  
Free Energies ◽  
Continuum Approach ◽  
Explicit Solvent ◽  
Linear Dimensionality Reduction ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Solvation Free Energies

<div><div><div><p>Toward practical modeling of local solvation effects of any solute in any solvent, we report a static and all-quantum mechanics based cluster-continuum approach for calculating single ion solvation free energies. This approach uses a global optimization procedure to identify low energy molecular clusters with different numbers of explicit solvent molecules and then employs the Smooth Overlap for Atomic Positions (SOAP) kernel to quantify the similarity between different low energy solute environments. From these data, we use sketch-map, a non-linear dimensionality reduction algorithm, to obtain a two-dimensional visual representation of the similarity between solute environments in differently sized microsolvated clusters. Without needing either dynamics simulations or an a priori knowledge of local solvation structure of the ions, this approach can be used to calculate solvation free energies with errors within five percent of experimental measurements for most cases.</p></div></div></div>

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