scholarly journals Layout Guide for Design of a Novel Wheelchairs with Circumferential Linkage using Microsoft Word

2021 ◽  
Vol 2113 (1) ◽  
pp. 012031
Author(s):  
Zhilin Zhao
Keyword(s):  
Modular Design ◽  
Planetary Gear ◽  
The Elderly ◽  
Gear Train ◽  
Wheelchair Users ◽  
Microsoft Word ◽  
Steering Mechanism ◽  
Dimensional Parameters ◽  
Design Characteristics ◽  
Walking Mechanism

Abstract In recent decades, the aging of the world’s population has intensified, and the number of people with disabilities caused by various disasters and diseases has gradually increased. Most of the elderly, frail and disabled people will choose wheelchairs as their means of transportation. However, ordinary wheelchairs are unable to climb stairs, especially in cities, which seriously limits the range of activities of wheelchair users and affects their daily life. Hence, it is of great significance and value to design an intelligent building climbing wheelchair with appropriate price, stability and safety. This paper designs a multi-functional planetary height adjustable building climbing wheelchair with simple structure and low price. Firstly, a multi-functional building climbing wheelchair based on planetary gear train is designed by using modular design idea, including ground walking mechanism, in place steering mechanism, center of gravity adjustment mechanism and Seat leveling mechanism. The working principle and design characteristics of each mechanism are analyzed in detail. Then, through the analysis of the mathematical model of the climbing mechanism, the dimensional parameters of the three-star wheel set are determined. According to the power demand of wheelchair, the power system is selected and analyzed. It provided a new possibility for the wheelchair application and also for those in need.

Dynamic Analysis and Simulation of a New Steering Mechanism for Point-the-Bit Rotary Steerable System

2013 ◽  
Vol 712-715 ◽  
pp. 1401-1405
Author(s):  
Yuan Zhi Li ◽  
Wen Tie Niu ◽  
Hong Tao Li ◽  
Shuai Li
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
Design Procedure ◽  
Planetary Gear ◽  
Horizontal Wells ◽  
Gear Train ◽  
Force Analysis ◽  
Drilling Tools ◽  
Steering Mechanism ◽  
Extended Reach Drilling

In oilfield exploitation, automatically directional steering can only be achieved with rotary steerable system (RSS). The designed well trajectories have become more complicated e.g. horizontal wells, extended reach drilling wells and 3D multi-target wells. To drill these complicated wells, new drilling tools are urgently needed. This paper proposed a new steering mechanism for point-the-bit RSS. The new steering mechanism uses a set of universal joints to avoid the high alternative strain on drilling mandrel, and it uses a specific eccentric planetary gear train to offset the drilling mandrel to achieve directional steering. Design procedure, Solid modeling, Force analysis and dynamic simulation have been discussed for further dynamic analysis towards the confirmation of the steering performance.

scholarly journals Validation of an Instrumented Wheelchair Hand Rim

2017 ◽  
Author(s):  
Alan Gaglio ◽  
Scott Daigle ◽  
Elizabeth Gacek ◽  
Omid Jahanian ◽  
Brooke Slavens ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Joint Pain ◽  
Planetary Gear ◽  
The United States ◽  
Gear Ratio ◽  
Gear Train ◽  
Wheelchair Propulsion ◽  
Wheelchair Users ◽  
Manual Wheelchair ◽  
High Incidence

An estimated 3.26 million manual wheelchair users (MWUs) exist in the United States [1]. MWUs report a high incidence of upper extremity joint pain largely attributed to wheelchair propulsion, which exposes the upper limbs to high forces and torques repetitively over time [2]. There exists a clear need for assistive wheelchair technologies capable of reducing the loads experienced by the upper extremity joints during propulsion. IntelliWheels, Inc. has developed multi-geared wheel systems, including both low and high gear systems, where a planetary gear train connects the wheel hub to the wheel hand rim. Decreasing gear ratio, we hypothesize, may reduce the forces and torques required by the user during propulsion. To evaluate this claim, we constructed and validated an instrumented wheelchair hand rim system capable of use on either geared or standard wheelchair wheels. Commercially available devices exist to perform wheelchair kinetics, such as the SmartWheel (SW) (Three River Holdings LLC; Mesa, AZ, USA), however, these devices require the use of a manufacturer specified wheel. As a result, a custom solution was required to interface with the geared wheels used in this study.

Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

2015 ◽  
Author(s):  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Haofei Wang ◽  
Heyun Bao ◽  
Miaomiao Li
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Friction ◽  
Planetary Gear ◽  
Gear Train ◽  
Variable Step Size ◽  
Step Size ◽  
Planetary Gear Train ◽  
Gear Mesh ◽  
Meshing Stiffness ◽  
Nonlinear Dynamics Model

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.

A New Technique Based on Loops to Investigate Displacement Isomorphism in Planetary Gear Trains

2002 ◽  
Vol 124 (4) ◽  
pp. 662-675 ◽  
Author(s):  
V. V. N. R. Prasad Raju Pathapati ◽  
A. C. Rao
Keyword(s):  
Graph Isomorphism ◽  
Planetary Gear ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Graph Representation ◽  
Kinematic Structure ◽  
Graph Representations ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
A New Technique

The most important step in the structural synthesis of planetary gear trains (PGTs) requires the identification of isomorphism (rotational as well as displacement) between the graphs which represent the kinematic structure of planetary gear train. Previously used methods for identifying graph isomorphism yielded incorrect results. Literature review in this area shows there is inconsistency in results from six link, one degree-of-freedom onwards. The purpose of this paper is to present an efficient methodology through the use of Loop concept and Hamming number concept to detect displacement and rotational isomorphism in PGTs in an unambiguous way. New invariants for rotational graphs and displacement graphs called geared chain hamming strings and geared chain loop hamming strings are developed respectively to identify rotational and displacement isomorphism. This paper also presents a procedure to redraw conventional graph representation that not only clarifies the kinematic structure of a PGT but also averts the problem of pseudo isomorphism. Finally a thorough analysis of existing methods is carried out using the proposed technique and the results in the category of six links one degree-of-freedom are established and an Atlas comprises of graph representations in conventional form as well as in new form is presented.

Dynamics of the Gear Train Set in Wind Turbine

2011 ◽  
Vol 697-698 ◽  
pp. 701-705
Author(s):  
D.D. Ji ◽  
Y.M. Song ◽  
J. Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Harmonic Balance Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Cartesian Coordinate ◽  
The Impact

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

Analysis of Models for Torsional Vibration of Shaft System With Planetary Gearing

1997 ◽  
Author(s):  
Jinghui Sun ◽  
Lee Liu ◽  
William N. Patten
Keyword(s):  
Torsional Vibration ◽  
Planetary Gear ◽  
Gear Train ◽  
Mathematical Treatment ◽  
Dynamic Parameters ◽  
Mass Model ◽  
Planar Model ◽  
Shaft System ◽  
Effective Dynamic ◽  
Single Mass

Abstract The kinematics of planetary gearing are complex; thus, making it difficult to build an effective dynamic model. In this paper, a single-mass model of a planetary gear and shaft system is developed to study the torsional vibration of the mechanism. Two new models of the system are proposed: (a) a fictitious co-planar model and (b) an equivalent shaft model. The results from the calculations and analyses using these models indicate that: 1) the single-mass model and the general rotary model are both limited, either mathematically or geometrically; 2) the fictitious co-planar model includes all of the geometric and dynamic parameters of the general rotary model, and it can be connected with the shaft system easily; and 3) using a mathematical treatment, the equivalent shaft model is demonstrated to be the most useful and most effective model for the calculation of torsional vibration of a shaft and planetary gear train.

Vibrational Monitoring of Nested Planetary Geartrain with Unground Pinion

2021 ◽  
Vol 263 (5) ◽  
pp. 1471-1487
Author(s):  
Jianxiong Feng ◽  
Yangfan Liu ◽  
Kai Ming Li
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Time History ◽  
Critical Factor ◽  
Planetary Gear ◽  
Gear Train ◽  
Frequency Spectrum Analysis ◽  
Vibration Strength ◽  
Automobile Transmissions ◽  
Modulation Sideband

The nested planetary gear train, which has two integrated single-stage planetary gearsets, is one of the newly developed compound gear train that has been successfully applied to the automobile transmissions. In the current study, a certain type of gear fault in the nested gear train, ungrounded pinion, is investigated using a non-destructive approach monitoring its vibration levels. A novel experimental test stand with open and vertical setup has been designed to collect the vibrational data by mounting the accelerometer directly to the gear clutches. Each of the two layers of the compound gear was tested separately. The measured vibrational data were processed with several signal processing techniques, which includes (a) frequency spectrum analysis, (b) time synchronous averaging (TSA) and (c) modulation sideband analysis. The experimental results show that the existence of the ungrounded pinion can be identified with the frequency spectrum analysis of the vibrational data. In addition, the modulation sidebands are also modeled using a modified version of the traditional technique of physical signal modeling. It is shown that the relative phase of the planet and the meshing vibration strength changed by the unground gear is the critical factor for determining the modulation sideband behavior. In addition, the location of the ungrounded pinion can also be determined by the time history processed by TSA.

Specific Conditions of A I ¯ -Planetary Gear Train

2019 ◽  
pp. 27-30
Author(s):  
Kiril Arnaudov ◽  
Dimitar Petkov Karaivanov
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Planetary Gear Train
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