scholarly journals Dynamic Analysis of Intermittent-Motion Conveyor Actuator

Actuators ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 174
Author(s):  
Alexander Prikhodko
Keyword(s):  
Gear Ratio ◽  
Transport Systems ◽  
Mechanical Transmission ◽  
Initial Link ◽  
Input Shaft ◽  
Single Mass ◽  
The Masses ◽  
Almost All ◽  
Design And Manufacture ◽  
Intermittent Motion

Conveyors are one of the important components of transport systems and are used in almost all branches of mechanical engineering. This paper investigates the dynamics of the intermittent motion conveyor mechanical system. The mechanical transmission is a planetary mechanism with elliptical gears, in which the intermittent motion of the output shaft is provided by a variable gear ratio of non-circular gears. A single-mass dynamic model is built by reducing the masses, forces and moments to the initial link, which is the input shaft of the mechanism. The solutions of the equations of initial link motion were obtained using two methods, the energy-mass method and the third-order Hermite method. Dynamic studies by the energy-mass method made it possible to determine flywheel moment of inertia to reduce the coefficient of initial link rotation irregularity. The convergence of the functions of the initial link angular velocity obtained by both methods was confirmed. The results can be used for further force analysis, strength calculations, design and manufacture of the conveyor.

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.

scholarly journals Design solutions overview of single-stage universal gear reducers

2020 ◽  
Vol 317 ◽  
pp. 01005
Author(s):  
Milan Rackov ◽  
Siniša Kuzmanović ◽  
Ivan Knežević ◽  
Maja Čavić ◽  
Marko Penčić ◽  
...  
Keyword(s):  
Graphic Design ◽  
Gear Ratio ◽  
Single Stage ◽  
Not Given ◽  
Housing Design ◽  
Different Dimensions ◽  
Complex Construction ◽  
Design Solutions ◽  
Almost All ◽  
Further Development

Today, for almost all products, the appearance is very important. Thus, for example, the appearance of universal gear reducers was not given so much attention, but today there are many very interesting solutions of shape, colour and graphic design. It should have in mind that universal gear reducers have much complex construction comparing them with special gear reducers. In the same time, they have to provide different positions and way of mounting and different speeds with different powers (torques) at the output shaft. Particularly, it should be noticed, that within all universal gear reducers single-stage gear units are nowadays increasingly used because their gear ratio values are increased (values of gear ratio can go up to 15) so that these reducers largely cover most of the two-stage gear reducers with their gear ratio values, so thereby their exploitation is significantly increased. Single-stage gear reducers are very simple products, and today there is a large number of manufacturers of such product. However, their mounting dimensions and way of mounting are not defined by a standard, so there is a variety of units with different dimensions and way of mounting. Although, most manufacturers look up to dimensions of leading manufacturers (usually SEW) in order to ensure greater exchangeability of their gear units. It is interesting to note, that most manufacturers tend to adopt the design of housing that will be substantially different from competing solutions. The reason is probably to avoid the possibility of being accused of copying someone else’s solution. However, there are manufacturers that retain almost identical housing design as a competing solution (probably they bought the licence or the solution is copied without permission). This paper considers only the design solutions of single-stage gear reducer in order to indicate the expected directions of their further development.

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.

scholarly journals RESEARCH FEATURES OF AEROELASTIC OSCILLATIONS OF UNMANNED AERIAL VEHICLES WITH ELECTRIC ACTUATOR OF RUDDERS

2018 ◽  
Vol 21 (4) ◽  
pp. 73-83
Author(s):  
A. V. Bykov ◽  
S. G. Parafes ◽  
V. I. Smyslov
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Modular Design ◽  
Experimental Studies ◽  
Operation Time ◽  
Gear Ratio ◽  
Elastic Structure ◽  
Normal Operation ◽  
Technical Problems ◽  
Aerial Vehicles ◽  
Almost All

Designing a modern flight vehicle is associated with the need to solve many scientific and technical problems. These tasks include the prevention of insecure self-oscillations in flight, taking into account the elasticity of the structure. These problems relate to dynamic aeroelasticity, a science that examines the interaction of an elastic structure (at its oscillation) with an air flow. Maneuverable unmanned aerial vehicles (UAVs) are considered. Since UAVs are essentially not used without an automatic control system (ACS), its presence must be taken into account when considering the vibrations of an elastic structure in flight. The influence of the elasticity of UAV design on the operation of ACS in flight is manifested in the possibility of self-oscillations in the loop "elastic UAV – ACS". Self-oscillations lead to disruption of normal operation of the onboard equipment or its failure. The complexity of the problem requires its consideration at almost all stages of UAV’s development, including the creation of a prototype and testing. The computational and experimental studies of the characteristics of elastic oscillations in the UAV flight of the cross-shaped scheme are considered. The features of these UAVs (options with a modular design, the nonlinearity of the airframe, rudders, ACS, and others) due to a significant amount of testing that is the basis for the calculations. Electric actuators have a small continuous operation time, and resource use, there are gearboxes with a large gear ratio and backlashes. This determines the dependence of the rotation rigidity of the rudders on the amplitude and frequency, as well as a significant increase in the total moments of inertia. The technique of bench experiment with obtaining data to assess the boundaries of the flutter and the boundaries of the stability of the loop "elastic UAV – ACS" is given. The questions of improvement of the stabilization system of UAV required for the study of its stability at frequencies of elastic oscillations are considered, as well as the evaluation of the limiting cycles of self-oscillations is given.

scholarly journals Cell-division pattern and phylogenetic analyses of a new ciliate genus Parasincirra n. g. (Protista, Ciliophora, Hypotrichia), with report of a new soil species, P. sinica n. sp. found from northwest China

2020 ◽  
Author(s):  
Chen Shao ◽  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Khaled A.S. Al-Rasheid ◽  
...  
Keyword(s):  
New Genus ◽  
Phylogenetic Analyses ◽  
Posterior Part ◽  
Northwest China ◽  
Molecular Data ◽  
New Taxon ◽  
Division Pattern ◽  
Exact Position ◽  
Single Mass ◽  
Almost All

Abstract Background: Ciliated protists, a huge assemblage of unicellular eukaryotes, are extremely diverse and play important roles in ecosystem in almost all kinds of habitats. Even though there is a growing recognition that those organisms associate with many ecological or environmental processes, their biodiversity, due to many reasons, is poorly understood and many biotopes (e.g. the soil in desert area in Asia) remain largely unknown or unconsidered. Here we document an undescribed form found in sludge soil in a halt-desert inland in China and the taxonomic/ morphogenetic surveys indicate that it represents a new genus and new species, Parasincirra sinica n. g., n. sp. which is supported also by molecular data.Results: This new, monotypic genus Parasincirra n. g. is defined by having three frontal cirri, an amphisiellid median cirral row about as long as the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) frontoventral-transverse cirral anlagen II to VI are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellidae Jankowski, 1979. The morphological/ morphogenetical differences between the new genus/species and Uroleptoides Wenzel, 1953/ Parabistichella Jiang et al., 2013, as well as other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra.

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.

STOL Aircraft—A Perspective

1968 ◽  
Vol 72 (685) ◽  
pp. 11-33 ◽  
Author(s):  
R. D. Hiscocks
Keyword(s):  
High Performance ◽  
Transport Systems ◽  
Total System ◽  
Operating Environment ◽  
Surface Transport ◽  
Transport Aircraft ◽  
Air Space ◽  
The Cost ◽  
Lifting System ◽  
Design And Manufacture

Summary The interest in Canada in the design and manufacture of utility aircraft with a short take-off and landing (STOL) performance may be traced back to the difficulties of surface transport in the early development of the country and the widespread use of bush aircraft. The leading characteristics of the STOL aircraft are examined with particular reference to design features essential to a short take-off and landing. The choice of powerplants and lifting systems is discussed with emphasis on the requirements for powered lift in the larger sizes of aircraft. The augmentor-wing is described as an example of an integrated propulsion lifting system with promise of a high performance. The phases of the take-off, transition, climb and landing manoeuvre are reviewed to illustrate the relative importance of various parameters in design and operation. The importance is stressed of good stability characteristics and effective controls for manoeuvring in a confined air space and a consistent landing performance. The requirements of a para-military mobile force tor a rapid response, deployment overseas and transportation in an area are examined. Some estimates are given of the probability of finding suitable airstrips in a particular region and the cost of constructing new airfields in a dynamic situation. The operating environment in potentially troubled areas of the world is examined briefly to provide guidance in design. The costs of a military supply system are discussed using various modes of transport which include trucks, helicopters, STOL and conventional transport aircraft with results which suggest that the system employing STOL aircraft in the tactical theatre has advantages in cost and effectiveness. Attention is drawn to the growing requirement for shorthaul, commuter and air taxi aircraft with STOL characteristics. Reference is made to the increases in air travel and the widespread use of large transport aircraft which have encouraged the movement of airports from urban centres at a time when city growth and congestion render surface transport increasingly difficult. The relative costs of commercial systems using the helicopter and STOL aircraft are examined. It is shown that the cost of STOL ports is not an excessive portion of total system costs when all factors are taken into account. Some forecasts are made as to future development trends in transport systems using STOL aircraft.

A study of the physical properties of SB2s with both the visual and spectroscopic orbits

2020 ◽  
Vol 492 (2) ◽  
pp. 2709-2721
Author(s):  
Luca Piccotti ◽  
José Ángel Docobo ◽  
Roberta Carini ◽  
Vakhtang S Tamazian ◽  
Enzo Brocato ◽  
...  
Keyword(s):  
Stellar Model ◽  
Spectroscopic Binaries ◽  
Adopted Model ◽  
Magnitude Diagram ◽  
Trigonometric Parallaxes ◽  
The One ◽  
The Masses ◽  
Almost All ◽  
Unique Mass ◽  
Good Agreement

ABSTRACT The study of a selected set of 69 double-lined spectroscopic binaries (SB2) with well-defined visual and spectroscopic orbits was carried out. The orbital parallax, the mass, the colour, and the luminosity of each component were derived from observational data for almost all of these systems. We have also obtained an independent estimation of the component masses by comparing the colour–magnitude diagram (CMD) to the stellar evolution tracks reported by Pietrinferni. Nearly all of the observational points on the CMD are located between two tracks of slightly different mass or which fall very close to the one corresponding to a unique mass value. The masses obtained from the stellar model are in good agreement with their empirical values determined by parallax techniques (orbital, Gaia, and dynamical). This means that our adopted model is rather reliable and can therefore be used to infer further information, such as the age of each component in the studied systems. Our results indicate a fair correspondence between the age of primaries and secondary stars within 3σ. Nevertheless, we caution that these age indications suffer of uncertainties due to both inhomogeneities/low precision of the adopted photometric data and possible systematics. Finally, it is statistically shown that along with the orbital and trigonometric parallaxes, the dynamical parallax can serve as a reliable tool for distance estimates.

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.

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