Theoretical and Experimental Study for An Improved Cycloid Drive Model

2019 ◽  
Vol 87 (1) ◽  
Author(s):  
Jean-Luc Dion ◽  
Zbigniew Pawelski ◽  
Vittorio Chianca ◽  
Zbigniew Zdziennicki ◽  
Nicolas Peyret ◽  
...  
Keyword(s):  
Gear Ratio ◽  
Rigid Bodies ◽  
Contact Dynamics ◽  
Operational Conditions ◽  
Input Shaft ◽  
Proposed Model ◽  
Output Load ◽  
Drive Model ◽  
Input Torque ◽  
Elasticity Effects

Abstract This paper describes an experimental and theoretical approach to evaluate cycloid drive reducer efficiency. The tests are carried out on 7.5 kW two-disc cycloid drive with a gear ratio of 19. The torque and speed are measured on the input and output shaft. The efficiency is calculated based on the obtained results. The main goal of the second part of the study is to deduce equations of cycloid reducer in order to predict and analyze experimental results. In this way, the following points are set for the simulation: a working condition in which the input speed and the output load are imposed; then, the output speed is determined by the gear ratio, and finally, the input torque is obtained by solving the dynamic problem. A new model for cycloidal reducers is proposed. This model is based on kinematics and dynamics of rigid bodies and a non-linear stiffness based on contact dynamics. The overall elasticity effects are all condensed between the input shaft and the cycloidal disk. The proposed model allows to predict the efficiency for several operational conditions and offer a drastic reduction of computational costs suitable for the optimization process.

scholarly journals An Efficient Contact Model for the Simulation of Cargo Airdrop Extraction Phase

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Leiming Ning ◽  
Jichang Chen ◽  
Mingbo Tong
Keyword(s):  
Degrees Of Freedom ◽  
Friction Model ◽  
Rigid Bodies ◽  
Contact Dynamics ◽  
Moving Frame ◽  
Contact Friction ◽  
Practical Implementation ◽  
Contact Formulation ◽  
Efficient Code ◽  
Extraction Phase

A high-fidelity cargo airdrop simulation requires the accurate modeling of the contact dynamics between an aircraft and its cargo. This paper presents a general and efficient contact-friction model for the simulation of aircraft-cargo coupling dynamics during an airdrop extraction phase. The proposed approach has the same essence as the finite element node-to-segment contact formulation, which leads to a flexible, straightforward, and efficient code implementation. The formulation is developed under an arbitrary moving frame with both aircraft and cargo treated as general six degrees-of-freedom rigid bodies, thus eliminating the restrictions of lateral symmetric assumptions in most existing methods. Moreover, the aircraft-cargo coupling algorithm is discussed in detail, and some practical implementation details are presented. The accuracy and capability of the present method are demonstrated through four numerical examples with increasing complexity and fidelity.

First Principle Based Control Oriented Gasoline Engine Model Including Lumped Cylinder Dynamics

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Ahmed Yar ◽  
A. I. Bhatti ◽  
Qadeer Ahmed
Keyword(s):  
Gasoline Engine ◽  
Angular Speed ◽  
Rigid Bodies ◽  
First Principle ◽  
Cylinder Pressure ◽  
Single Cylinder ◽  
Engine Model ◽  
Proposed Model ◽  
Engine Cylinder ◽  
Diagnostic Capabilities

A novel first principle based control oriented model of a gasoline engine is proposed which also carries diagnostic capabilities. Unlike existing control oriented models, the formulated model reflects dynamics of the faultless as well as faulty engine with high fidelity. In the proposed model, the torque production subsystem is obtained by integration of further two subsystems that is model of a single cylinder torque producing mechanism and an analytical gasoline engine cylinder pressure model. Model of a single cylinder torque producing mechanism is derived using constrained equation of motion (EOM) in Lagrangian mechanics. While cylinder pressure is evaluated using a closed form parametric analytical gasoline engine cylinder pressure model. Novel attributes of the proposed model include minimal usage of empirical relations and relatively wider region of model validity. Additionally, the model provides model based description of crankshaft angular speed fluctuations and tension in the rigid bodies. Capacity of the model to describe the system dynamics under fault conditions is elaborated with case study of an intermittent misfire condition. Model attains new capabilities based on the said novel attributes. The model is successfully validated against experimental data.

Kinematic Analysis and Design of Eccentric Rolling Transmission

2017 ◽  
Author(s):  
Stanislaw Pabiszczak ◽  
Adam Myszkowski ◽  
Roman Staniek ◽  
Lukasz Macyszyn
Keyword(s):  
Kinematic Analysis ◽  
Design Procedure ◽  
Gear Ratio ◽  
Output Shaft ◽  
Cad Model ◽  
The Novel ◽  
Rolling Bearings ◽  
Analysis And Design ◽  
Input Shaft ◽  
New Type

The paper shows an idea of a new type of mechanical gear — the eccentric rolling transmission. The main parts of that transmission are rolling bearings, mounted eccentrically on the input shaft which cooperate with the special-shaped cam wheels mounted on the output shaft. The number of rolling bearings is equal to the number of cam wheels. On the basis of kinematic analysis equations of the curve which describe a shape of cam wheels were determined for two different cases: in the first one the directions of shafts rotations were opposite, and in the second they were the same. Kinematic analysis of the novel transmission was carried out to determine maximum gear ratio depending on the adopted input parameters. As a result of analyses a design procedure of the eccentric rolling transmission and CAD model were prepared.

Linearization and Model Reduction of Contact Dynamics Simulation

2011 ◽  
Author(s):  
Jianxun Liang ◽  
Ou Ma ◽  
Caishan Liu
Keyword(s):  
Model Reduction ◽  
Multibody Systems ◽  
Reduction Method ◽  
Contact Dynamics ◽  
Dynamics Simulation ◽  
Dynamics Model ◽  
Time Step ◽  
Reduction Techniques ◽  
Proposed Model ◽  
Simulation Time

Finite element methods are widely used for simulations of contact dynamics of flexible multibody systems. Such a simulation is computationally very inefficient because the system’s dimension is usually very large and the simulation time step has to be very small in order to ensure numerical stability. A potential solution to the problem is to apply a model reduction method in the simulation. Although many model reduction techniques have been developed, most of them cannot be readily applied due to the high nonlinearity of the involved contact dynamics model. This paper presents a solution to the problem. The approach is based on a modified Lyapunov balanced truncation method. A numerical example is presented to demonstrate that, by applying the proposed model reduction method, the simulation process can be significantly speeded up while the resulting error caused by the model reduction is still within an acceptable level.

Optimization of Hydraulic Pressure for Continuously Variable Transmission

2011 ◽  
Vol 317-319 ◽  
pp. 529-532
Author(s):  
Kei Lin Kuo
Keyword(s):  
Torque Converter ◽  
Transmission Efficiency ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Hydraulic Pressure ◽  
Primary Input ◽  
Input Shaft ◽  
Variable Transmission ◽  
Labview Program ◽  
Set Up

Compared to conventional transmission layouts, Active continuously variable transmission (CVT) provides smoother gear shifting and gear ratio in smaller increments, and is, therefore, more accommodating the needs of both the driver and passengers. A few notable improvements are enhanced passenger comfort, higher transmission efficiency, and improved acceleration. Incorporating all of the above qualities has become a major developmental focus for the automotive industry, and the potential for improvement warrants further investigation. A CVT controls the gear ratio by changing the diameters of the primary (input) and the secondary (output) pulleys by adjusting the hydraulic pressure applied to each using valves. Hydraulic pressure in the channel is developed using a basic pump connected to the input shaft. Excess pressure produced at higher speed is wasted. This study aims to minimize this hydraulic pressure without affecting the transmission’s performance, in order to conserve energy. A user interface was set up and the CVT’s torque converter was modified such that the inner and outer shafts could be operated independently, allowing for full control of hydraulic pressure .This experiment successfully achieved, via a custom LabVIEW program, its goal of controlling the gear ratio between the primary and secondary pulleys whilst operating at lower pressures to those specified by the manufacturer. This proves that it is possible to fully control the CVT whilst operating at a reduced hydraulic pressure.

Damage Detectability Model of Pitch-Catch Configuration in Composite Plates

2017 ◽  
Vol 754 ◽  
pp. 387-390 ◽  
Author(s):  
Nan Yue ◽  
Zahra Sharif Khodaei ◽  
Ferri M.H. Aliabadi
Keyword(s):  
Wave Propagation ◽  
Damage Detection ◽  
Health Monitoring ◽  
Lamb Waves ◽  
Composite Plates ◽  
Detection Algorithm ◽  
Probability Of Detection ◽  
Operational Conditions ◽  
Proposed Model ◽  
Lamb Wave Propagation

Detectability of damage using Lamb waves depends on many factors such as size and severity of damage, attenuation of the wave and distance to the transducers. This paper presents a detectability model for pitch-catch sensors configuration for structural health monitoring (SHM) applications. The proposed model considers the physical properties of lamb wave propagation and is independent of damage detection algorithm, which provides a generic solution for probability of detection. The applicability of the model in different environmental and operational conditions is also discussed.

Innovative Multi Exercise Self Weight Machine Using Gear Changing Mechanism

2021 ◽  
Vol 14 ◽  
Author(s):  
Jasdev Bhatti ◽  
Amitoj Singh Sethi ◽  
Bhavneet Singh Gujral
Keyword(s):  
Kidney Diseases ◽  
Low Cost ◽  
Age Groups ◽  
Cost Effective ◽  
Gear Ratio ◽  
Maintenance Cost ◽  
Input Shaft ◽  
Intermediate Shaft ◽  
Manual Adjustment ◽  
Innovation Approach

Background: Background: The increase rate in global obesity is presenting a major public health spate to peoples of every age groups or region. Obesity increases health risks such as cardiovascular disease, cancer, diabetes, osteoarthritis, and chronic kidney diseases. Now a days, we have all seen the damage been done in humanity through the biggest world problem naming Covid,19. All past researches and traditional weight machines are found to be either plate loaded, or weight-stack loaded. The plate loaded machine requires location of various load plates and manual adjustment of load. Machines based on such techniques always have chances for user injury and to be a cumbersome task. Objective: The objective of developing new gym machine presents an innovation that provides a load lifting apparatus which does not require weight stacks or weight plates for the user to exercise, adapted to adjust user of various height and weight, requiring lower maintenance cost and more important is it’s safe and easy handling nature that offers cost effective alternative to existing devices. Methods: The present papers provide an innovation approach in developing multi exercise self-weight gym machine. Machine includes unique design with new features for holding handle during load lifting exercise, an input shaft having one or more first pulleys coupled to the handle for rotating the input shaft. An intermediate shaft having a first set of gears configured for selective engagement with the input shaft. Output shaft includes second set of gears which was configured for selective engagement with the intermediate shaft, and one or more second pulleys coupled for lifting one or more loads. A weight-based exercise machine depending on user weight will adds to its independency on adding or withdrawal of weight that leads to its low cost and weight. Addition of parallelogram linkages in its design benefitted in providing non-swing motion. The concept of maintaining proper resistance has also been an important factor during the design of machine. Patents: The paper present the idea of designing the multi self-weight exercise machines as an innovation of involving the gear change mechanism for user having different weights and height. Results: The results concerning the gear ratio for first and second lever are computed for respective machine. Effective gear ratio and standardized load values had been obtained towards weight lifted for 78 Kilogram to achieve load less or more than weight of the user. Conclusion: The machine designed has been proved to be efficient by involving innovative ideas and design consisting of as each engagement configuration of input shaft and intermediate shaft that further provide different gear ratio between the input, output & intermediate shaft. The concept of movable chairs in change of weight through gear mechanism and the use of machine in different exercises had proved it to be an effective and beneficial for users and manufacturer for its easy handling nature.

Large-Scale Parallel Multibody Dynamics With Frictional Contact on the GPU

2008 ◽  
Author(s):  
Dan Negrut ◽  
Alessandro Tasora ◽  
Mihai Anitescu
Keyword(s):  
Large Scale ◽  
Frictional Contact ◽  
Complementarity Problems ◽  
Linear Complementarity Problems ◽  
Rigid Bodies ◽  
Contact Dynamics ◽  
Iteration Algorithm ◽  
Symmetric Convex ◽  
Processing Unit ◽  
Multiple Data

In the context of simulating the frictional contact dynamics of large systems of rigid bodies, this paper reviews a novel method for solving large cone complementarity problems by means of a fixed-point iteration algorithm. The method is an extension of the Gauss-Seidel and Gauss-Jacobi methods with overrelaxation for symmetric convex linear complementarity problems. Convergent under fairly standard assumptions, the method is implemented in a parallel framework by using a single instruction multiple data (SIMD) computation paradigm promoted by the Compute Unified Device Architecture (CUDA) library for graphical processing unit (GPU) programming. The framework is anticipated to become a viable tool for investigating the dynamics of complex systems such as ground vehicles running on sand, powder composites, and granular material flow.

Advanced Seismic Analyses of “Apennine Churches” Stroked by the Central Italy Earthquakes of 2016 by the Non-Smooth Contact Dynamics Method

2019 ◽  
Vol 817 ◽  
pp. 309-316 ◽  
Author(s):  
Angela Ferrante ◽  
Elisa Ribilotta ◽  
Ersilia Giordano ◽  
Francesco Clementi ◽  
Stefano Lenci
Keyword(s):  
Seismic Vulnerability ◽  
Dynamic Properties ◽  
Central Italy ◽  
Rigid Bodies ◽  
Masonry Structure ◽  
Contact Dynamics ◽  
Numerical Analyses ◽  
Structural Behaviour ◽  
Major Purpose ◽  
Historical Masonry

The dynamic behaviour and the seismic vulnerability of different masonry “Apennine Churches”, dramatically damaged by the last shocks sequence of 2016 that occurred in Central Italy, have been studied in this paper by means of advanced 3D numerical analyses with the Discrete Element Method (DEM). Thus, a discontinuous approach has been used to assess the dynamic properties and the vulnerability of the masonry structure, through large deformations regulated by the Signorini’s law, concerning the impenetrability between the rigid bodies, and by the Coulomb’s law, regarding the dry-friction model. The major purpose of this study is to highlight that relevant data on the real structural behaviour of historical masonry can be provided through advanced numerical analyses. The comparison between the results of the numerical simulation and the survey of the existing crack pattern of the churches permitted to validate the used approach. Finally, from the results and conclusions of these cases study, it is possible to affirm that the used methodology can be applied to a wide variety of historical masonry structure in Europe.

A Self-Adaptively Loading Mechanism for Planetary Cylindrical Roller Traction Drives

2012 ◽  
Vol 479-481 ◽  
pp. 865-871
Author(s):  
De Sheng Chen ◽  
Xue Wen Du
Keyword(s):  
Normal Load ◽  
Logarithmic Spiral ◽  
Appreciable Amount ◽  
The Sun ◽  
Spin Motion ◽  
Traction Drive ◽  
Input Shaft ◽  
Traction Drives ◽  
Cylindrical Roller ◽  
Input Torque

A planetary cylindrical roller traction drive was developed. It is comprised of a sun roller, three planet rollers, an outer ring, a planet carrier and an input shaft. The sun roller is hollow, and is connected through three segments of logarithmic spiral profile to the input shaft. As the input shaft rotates relative to the sun roller, a wedging action takes place between the input shaft and the sun roller; this makes the sun roller produce a certain amount of radial displacement, so an appreciable amount of normal load is thus generated between the rollers of the planetary traction-drive device. The greater the input torque is, the stronger the strength of the wedging action, and the greater the contact load, and vice versa; so this device is self-actuating. Here, as cylindrical rollers are used in the planetary traction-drive device, the spin motion as would present in the case that tapered rollers are used will not occur. This design offers an alternative way to solve the problem of self-adaptively loading of planetary cylindrical roller traction-drive devices.

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