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.

A review of graph theory application research in gears

2015 ◽  
Vol 230 (10) ◽  
pp. 1697-1714 ◽  
Author(s):  
Hui-Ling Xue ◽  
Geng Liu ◽  
Xiao-Hui Yang
Keyword(s):  
Graph Theory ◽  
Power Flow ◽  
Planetary Gear ◽  
Mechanical Efficiency ◽  
Gear Train ◽  
Synthesis Process ◽  
Epicyclic Gear ◽  
Analysis And Synthesis ◽  
Theory Application ◽  
Gear Trains

Graph theory has been applied to gear train analysis and synthesis for many years, and it is an effective and systematic modeling approach in the design process of gear transmission. Based on more than 100 references listed in this paper, a review about the graph-based method for kinematic and static force analysis, power flow, and mechanical efficiency computation is presented. The method is based on the concept of fundamental circuit corresponding to a basic epicyclic gear train. A 1-dof epicyclic gear train and a two-stage planetary gear train are used to illustrate the application of this method. Besides, isomorphism identification in the synthesis process and enumeration of 1-dof epicyclic gear train graphs are surveyed particularly. Also, the computerized methods for detection of redundant gears and degenerate structures in epicyclic gear trains are reviewed, respectively.

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.

Meshing Efficiency Analysis of Two Degree-of-Freedom Epicyclic Gear Trains

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Essam Lauibi Esmail
Keyword(s):  
Reference Frame ◽  
Power Efficiency ◽  
Power Flow ◽  
Flow Direction ◽  
Efficiency Analysis ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
Two Degree Of Freedom

The concept of potential power efficiency is introduced as the efficiency of an epicyclic gear train (EGT) measured in any moving reference frame. The conventional efficiency can be computed in a carrier-moving reference frame in which the gear carrier appears relatively fixed. In principle, by attaching the reference frame to an appropriate link, torques can be calculated with respect to each input, output, or (relatively) fixed link in the EGT. Once the power flow direction is obtained from the potential power ratio, the torque ratios are obtained from the potential power efficiencies, the particular expression of the efficiency of the EGT is found in a simple manner. A systematic methodology for the efficiency analysis of one and two degree-of-freedom (DOF) EGTs is described, and 14 ready-to-use efficiency formulas are derived for 2DOF gear pair entities (GPEs). This paper includes also a discussion on the redundancy of the efficiency formulas used for 1DOF GPEs. An incomplete in the efficiency formulas in previous literature, which make them susceptible to wrong application, is brought to light.

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.

Nomographs for Kinematics, Statics and Power Flow Analysis of Epicyclic Gear Trains

2009 ◽  
Author(s):  
Essam L. Esmail ◽  
Hamed A. Hussen
Keyword(s):  
Electric Motor ◽  
Power Flow ◽  
Automatic Transmission ◽  
Flow Analysis ◽  
Gear Train ◽  
Innovative Design ◽  
Epicyclic Gear ◽  
Power Split ◽  
Gear Trains ◽  
Flow Through

A new methodology for constructing multi-axes nomographs is developed. Using this methodology, a unified general formulation for computing velocities and torques of any epicyclic-type transmission train is presented. To demonstrate and apply the new technique, Ravigneaux automatic transmission is used to show how the velocities, the torques and the power flow through the train can be simultaneously visualized on a single nomograph. The present methodology is judged to be more efficient than other methods and than the three-ax nomograph methodology. Using this methodology an innovative design of two-input transmission with only one electric motor/generator (MG) and without any rotating clutches is presented. The proposed design provides some of the benefits and flexibility of a power-split design by using the conventionally available Ravigneaux gear train in a simpler mechanical layout which makes the design compact, mechanically simple, and operationally flexible.

Mechanical Efficiency Analysis of a 16-Speed Bicycle Transmission Hub

2013 ◽  
Vol 284-287 ◽  
pp. 810-814 ◽  
Author(s):  
Yi Chang Wu ◽  
Pei Wun Ren
Keyword(s):  
Analytical Method ◽  
Power Flow ◽  
Planetary Gear ◽  
Mechanical Efficiency ◽  
Angular Speed ◽  
Efficiency Analysis ◽  
Gear Train ◽  
Flow Diagram ◽  
Gear Mesh ◽  
Analysis Process

This paper proposes an analytical method to evaluate the mechanical efficiency of the bicycle transmission hub. A 16-speed transmission hub, which consists of two transmission units and one differential unit, is presented first. By applying the concept of fundamental circuits, a step by step analysis process is then described to numerically calculate the angular speed, ideal torque and power flow, and actual torque and power flow by considering the gear-mesh loss of each link of the planetary gear train. Based on the power flow diagram, the mechanical efficiency at each speed of the transmission hub can be estimated.

Utilization of FPAA Technology for Emulation of Multiscale Power System Dynamics in Smart Grids

2011 ◽  
Vol 2 (2) ◽  
pp. 606-614 ◽  
Author(s):  
Anthony S. Deese ◽  
Chika O. Nwankpa
Keyword(s):  
Steady State ◽  
Power Systems ◽  
System Dynamics ◽  
Smart Grids ◽  
Power Flow ◽  
Transient Fault ◽  
Programmable Analog ◽  
Field Programmable ◽  
Physical Prototype ◽  
Field Programmable Analog Array

In this paper, the authors address computational issues associated with implementation of VLSI technologies-specifically, the utilization of field programmable analog array (FPAA) technology to analyze the steady-state as well dynamic behavior of nonlinear, multiscale power systems. Emphasis is placed on the following issues: adaptation of FPAA hardware for power flow analyses, design and construction of physical prototype, optimal hardware scaling, and application of emulation to transient fault analyses.

Torque and Power-Flow Analyses of Two Input Epicyclic-Type Transmission Trains

2008 ◽  
Author(s):  
Essam L. Esmail ◽  
Shaker S. Hassan
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Gear Train ◽  
Root Cause ◽  
Transmission Design ◽  
Epicyclic Gear ◽  
Systematic Methodology ◽  
Hybrid Transmission ◽  
The Given ◽  
Input Torque

This study contributes to the development of a systematic methodology for the torque and power flow analyses of two-input epicyclic gear mechanisms (EGMs) with or without reaction link, based upon the concept of fundamental circuit. The studies on power flow analysis of EGMs are mostly done in the context of efficiency formulations. In the opinion of the authors, the design process of two-input mechanism involves not only finding the configuration that provides the correct velocity ratios, but also meets other dynamic and kinematic requirements and ensures that the two inputs have a mutually constructive nature. To demonstrate the analysis, a new motor/generator integrated hybrid transmission design is used to show how the torque acting on each link of an epicyclic gear train (EGT) can be systematically solved in terms of input torque(s) and/or controlled output torque. This paper presents a unification of kinematic and torque balance approaches for the analysis of two-input epicyclic-type transmission trains. The results presented are meant to deepen the knowledge as to how and why a two-input epicyclic-type transmission should operate in a certain way under the given conditions. In the process, this paper explores the theoretical bases of operation of the Toyota Hybrid System (THS) and the root cause of some confusion in the field of EGTs.

Modeling and Simulation of an Inertia-Type Infinitely Variable Transmission

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Giovanni Berselli
Keyword(s):  
Mathematical Model ◽  
Modeling And Simulation ◽  
Numerical Simulations ◽  
Gear Train ◽  
Linkage Mechanism ◽  
Manual Gearbox ◽  
Epicyclic Gear ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Four Bar Linkage

A fully mechanical, infinitely variable transmission (IVT) based on the use of an oscillating inertia is described. The system includes a four-bar linkage mechanism, an epicyclic gear train, and a pair of one-way clutches. The IVT can be used in place of both gearbox and clutch in self-propelled vehicles. A mathematical model is presented. Numerical simulations compare the behavior of a car fitted with a manual gearbox and the same car fitted with the IVT.

scholarly journals A Generalized Approach to the Steady-State Efficiency Analysis of Torque-Adding Transmissions Used in Renewable Energy Systems

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4568 ◽  
Author(s):  
Mircea Neagoe ◽  
Radu Saulescu ◽  
Codruta Jaliu ◽  
Petru A. Simionescu
Keyword(s):  
Steady State ◽  
Power Flow ◽  
Planetary Gear ◽  
Mechanical Efficiency ◽  
Efficiency Analysis ◽  
Mechanical Power ◽  
Electric Generator ◽  
Rotor Systems ◽  
Marine Current ◽  
State Regime

The paper presents a general approach to the steady-state efficiency analysis of one degree of freedom (1-DOF) speed increasers with one or two inputs, and one or two outputs, applicable to wind, hydro and marine-current power generating systems. The mechanical power flow, and the efficiency of this type of complex speed increasers, are important issues in the design and development of new power-generating systems. It is revealed that speed increases, with in-parallel transmission of the mechanical power from the wind or water rotors to the electric generator, have better efficiency than serial transmissions, but their efficiency calculus is still a challenging problem, solved in the paper by applying the decomposition method of complex speed increasers into simpler component planetary gear sets. Therefore, kinematic, steady-state torque and efficiency equations are derived for a generic 1-DOF speed increasers with two inputs and two outputs, obtained by connecting in parallel two gear mechanisms. These equations allow any speed increaser to be analysed with two inputs and one output, with one input and two outputs, and with one input and one output. We discuss a novel design of a patent-pending planetary-gear speed increaser, equipped with a two-way clutch, which can operate (in combination with the pitch adjustment of the rotors blades) in four distinct configurations. It was found that the mechanical efficiency of this speed increaser in the steady-state regime is influenced by the interior kinematic ratios, the input-torque ratio and by the meshing efficiency of its individual gear pairs. The efficiency of counter-rotating dual-rotor systems was found to be the highest, followed by systems with counter-rotating electric generator, and both have higher efficiency than conventional systems with one rotor and one electric generator with fixed-stator.

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