Capturing Assembly Constraints of Experimental Setups in a Virtual Laboratory Environment

Author(s):  
El-Sayed Aziz ◽  
Yizhe Chang ◽  
Sven K. Esche ◽  
Constantin Chassapis

Recently, multi-player game engines have been explored regarding their potential for implementing virtual laboratory environments for engineering and science education. In these developments, the virtual assembly process of the laboratory equipment is a critical step, and a detailed formalized description of how different components of the experimental equipment are to be joined in the assembly process is necessary. This description includes the joint types (lower and upper kinematic pairs) and the associated degrees of freedom, the resulting mobility of the assembly as well as the joint fit requirements. In this paper, a formalized representation of the assembly process that captures the information on the joint kinematics and the components’ degrees of freedom generated when assembling laboratory equipment in a virtual laboratory environment will be discussed. A planetary gear train system will be used as an example to illustrate the proposed method. In particular, the structure of the assembly of a planetary gear train system involves assembly constraints between a group of components (sun, planet and ring gears, shafts, planet carrier assembly, etc.) that generate the desired relationship between the input and output motions. This paper will identify important requirements for modeling different configurations of planetary gear train assemblies within a game-based virtual laboratory environment. These requirements include the positioning and the orienting of the components, the verification of the kinematic joints, the propagation of the mating constraints and the capturing of the joint attributes.

Author(s):  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Haofei Wang ◽  
Heyun Bao ◽  
Miaomiao Li

A new nonlinear dynamics model of the double helical planetary gear train with 44 degrees of freedom is developed, and the coupling effects of the sliding friction, time-varying meshing stiffness, gear backlashes, axial stagger as well as gear mesh errors, are taken into consideration. The solution of the differential governing equation of motion is solved by variable step-size Runge-Kutta numerical integration method. The influence of tooth friction on the periodic vibration and nonlinear vibration are investigated. The results show that tooth friction makes the system motion become stable by the effects of the periodic attractor under the specific meshing frequency and leads to the frequency delay for the bifurcation behavior and jump phenomenon in the system.


2015 ◽  
Vol 39 (3) ◽  
pp. 431-441 ◽  
Author(s):  
Yi-Chang Wu ◽  
Tze-Cheng Wu

This paper presents embodiment design of 5-speed rear drive hubs for bicycles. A 7-link, 2-degrees of freedom (DOF) compound planetary gear train as the main body of a rear drive hub is introduced. The relationship between the number of coaxial links of a planetary gear train and the number of gear stages that a drive hub can provide with is discussed. By means of kinematic analysis, four speed ratios of the planetary gear train are derived, which represents four forward gears of the rear drive hub. By adding a direct-drive gear, five forward gears can be provided and two feasible clutching sequence tables are synthesized. Manual translational-type gear-shifting mechanisms are further designed to incorporate with the planetary gear train for appropriately controlling the gear stage. The power-flow path at each gear stage is checked to verify the feasibility of the proposed design. Finally, two novel 5-speed bicycle rear drive hubs are presented.


2018 ◽  
Vol 211 ◽  
pp. 17003
Author(s):  
Heyun Bao ◽  
Guanghu Jin ◽  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Xiaozhu Zou

The planetary gear transmission with double moduli and pressure angles gearing is proposed for meeting the low weight high reliability requires. A dynamic differential equation of the NGW planetary gear train system with double and pressure angles is established. The 4-Order Runge-Kutta numerical integration method is used to solve the equations from which the result of the dynamic response is got. The dynamic load coefficients are formulated and are compared with those of the normal gear train.The double modulus planetary gear transmission is designed and manufactured. The experiment of operating and vibration are carried out and provides.


2019 ◽  
Vol 287 ◽  
pp. 04001
Author(s):  
Kiril Arnaudov ◽  
Stefan Petrov ◽  
Emiliyan Hristov

Planetary gear trains can work differently, namely, with F=1 degree of freedom, i.e. as reducers or multipliers, and also with F=2 degrees of freedom, i.e. as differentials. Moreover, with a two-motor drive they work as a summation planetary gear train and with a one-motor drive, they work as a division planetary gear train. The most popular application of planetary gear trains is as a differential which is bevel and is produced globally in millions of pieces. Some of the cylindrical planetary gear trains can also be used as differentials. Although less often, they are used in heavy wheeled and chain vehicles such as trailer trucks, tractors and tanks. They are also very suitable for lifting machines with a two-motor drive which provides maximum security for the most responsible cranes, such as the metallurgical ones. Initially the paper presents some simple, i.e. single-carrier cylindrical planetary gear trains, both with external and internal meshing, driven by 2 motors. Their kinematic capabilities and velocity, respectively, are considered to realize the necessary gear ratio. Finally, the case of a compound two-carrier planetary gear train is considered, which is composed of 2 simple planetary gear trains. This shows that not only the simple planetary gear trains, i.e. the single-carrier ones, can work as differentials.


Author(s):  
Yizhe Chang ◽  
El-Sayed Aziz ◽  
Sven K. Esche ◽  
Constantin Chassapis

Current online laboratory systems based on either remotely operated hardware or pure software simulations are often criticized for lacking experimental setup experience and for being limited to the data collection and result analysis aspects of traditional hands-on laboratories. One possible solution for overcoming these shortcomings is to use a multi-player computer game engine for implementing interactive laboratory environments. Taking advantage of game technology, the students are enabled to simultaneously interact with laboratory equipment in the virtual laboratory and to communicate with each other through voice or chat. In particular, assembling the experimental equipment before using it in some experimental procedure can become part of the laboratory exercise. In this article, a virtual gear design laboratory environment for a junior-level undergraduate mechanical engineering course on mechanisms and machine dynamics is presented. This virtual laboratory environment implemented using a multiplayer computer game engine provides the students with the flexibility to perform various experiments related to the concepts of the fundamental law of gearing and to planetary motion of gears. In this environment, the students can work in teams to interactively select and cooperatively assemble gear train components piece by piece into a more complex experimental apparatus. This article describes the assembly logic that is used to combine individual components into experimental setups as part of the experimental procedure in student laboratories. Furthermore, the game environment can be equipped with functionality for monitoring the students’ progress and learning outcomes, thus enabling skill-based assessment.


Author(s):  
Yi Zhang ◽  
Zhi Wu

Abstract Planetary gear train systems are widely used in automotive transmissions due to their compactness, large reduction ratios and degrees of freedom available for the selection of gear ratios. The analysis of gear ratios and torque relations among the elements of a planetary train system is often difficult due to the complexity of the planetary train structure. This is especially the case for automotive transmissions using planetary train system where the members for input and output and the members that are fixed or interconnected must be changed in the clutch engagement schedule to obtain multiple transmission speeds. This paper proposes a systematic approach that simplifies the gear ratio and torque analysis based on the basic planetary train characteristics. The approach can be effectively used for the analysis of gear ratio and static torques for power transmissions consisting of parallel planetary trains. A case study of multi-speed automotive transmission based on the approach is included in the paper.


2011 ◽  
Vol 308-310 ◽  
pp. 307-310
Author(s):  
Xiao Mei You ◽  
Lei Meng ◽  
Xing Guo Ma ◽  
Bang Chun Wen

Based on the multi-body dynamics theory and visualization technology, a planetary gear train system is studied in RecurDyn. The multi-body dynamics model of the 2K-H planetary gear train system is built to do the visual analysis on dynamic characteristic of the planetary gear system severally in the ideal steady-state condition and the random-load condition, than the real-time dynamic contact stress and some other meaningful results of the key components are gained. Compared the related simulation results with that of the theoretical analysis, it is known that two kinds of results are consistent and the simulation analysis on the planetary gear train system is correct and accuracy. From the research above, the new idea and analytical tool are provided for the traditional, static, "redundancy" design method of the gear system, and also the effective technical mean is provided in conceptual design of complex mechanical products to predict the performance, then to reduce the "birth defects" in design stage and also an effective and efficient technical means for engineering applications is offered for optimal design and developing new product on gear train system.


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