scholarly journals Structural and kinematic analysis of a shutter from monocoque trailer

2019 ◽  
Vol 112 ◽  
pp. 03021
Author(s):  
Lucreţia Popa ◽  
Ştefan-Iulian Moise ◽  
Victor Moise ◽  
Vasilica Ştefan ◽  
Iulian Tabără
Keyword(s):  
Kinematic Analysis ◽  
Hydraulic Cylinder ◽  
Agricultural Products ◽  
High Speeds ◽  
Hydraulic Cylinders ◽  
Active Motor ◽  
Computational Procedures ◽  
Shutter Mechanism ◽  
Pneumatic Cylinders

The bodies of trucks or trailers are provided with automatic folding shutters to ease the discharge of the transported materials. Typically, these shutters are powered by mechanisms that have active motor groups such as RRTaR or RR-RR-RTaR (i.e. motor dice or triads) and passive motor groups such as RRR, RR-RR-RR etc. If the technological forces are high and the relative speeds between the elements forming the steering coupler are small, the motor groups are formed by rigid bars and hydraulic cylinders. If relatively high gear ratios are required, then pneumatic cylinders may be used. If required relatively high speeds in the driving couplings, then you can use pneumatic cylinders. This paper presents structural and kinematic analysis of a shutter from a trailer used to transport bulk agricultural products, discharge towards the back. For the kinematic analysis of the folding shutter mechanism, computational procedures written in the Matlab syntax are used. The results of the calculations are presented in tabular and diagrams. After the cinematic analysis of the mechanism, it is possible to perform its cinetostatic analysis, i.e. the determination of the reactions from the kinematic couplers, as well as the hydraulic force in the hydraulic cylinder. Results can be used for the dimensional verification of the chosen elements.

scholarly journals Structural, kinematic and kinetostatic analysis of a manure spreader equipped by a mobile platform with articulated elements

2020 ◽  
Vol 180 ◽  
pp. 03009
Author(s):  
Lucretia Popa ◽  
Stefan-Iulian Moise ◽  
Victor Moise ◽  
Vasilica Stefan ◽  
Ioan Ganea-Christu
Keyword(s):  
Kinematic Analysis ◽  
Mobile Element ◽  
Hydraulic Cylinder ◽  
Mobile Platform ◽  
Organic Fertilization ◽  
Physical Effort ◽  
Special Construction ◽  
Hydraulic Cylinders ◽  
Calculation Procedures

Organic fertilization involves working with machines by a special construction, suitable for the material to be spread, machines that have, in most cases, chain conveyors with scrapers attached to the chains. In some cases, the conveyor chain may break, due to the jams, and the need for manual unloading of the bunker (bucket) appears, which requires a great physical effort, the unloading being made by the operator, using a shovel. The construction of the platform using mobile, articulated elements would greatly facilitate the unloading at the bottom of the bunker and would eliminate the physical effort of the operator. This article presents the structural, kinematic and kinetostatic analysis of a mechanism designed for actuating a mobile platform, which is part of a manure spreader, composed of articulated elements driven by hydraulic cylinders. For the kinematic analysis of the mobile element platform’s mechanism, calculation procedures written in the Matlab syntax are used. After the kinematic analysis of the mechanism, the kinetostatic analysis is performed, i.e. the determination of the reactions from the kinematic couplings, as well as the hydraulic force from the hydraulic cylinder. The results can be used for dimensional verification of the mechanism components, thus contributing to the optimization of the mechanism.

An analytical approach to evaluate the maximum load carrying capacity for pin-mounted telescopic hydraulic cylinder

2020 ◽  
Vol 234 (19) ◽  
pp. 3919-3934
Author(s):  
Jatin Prakash ◽  
Sumit Kumar Gupta ◽  
PK Kankar
Keyword(s):  
Finite Element ◽  
Analytical Approach ◽  
Maximum Load ◽  
Hydraulic Cylinder ◽  
Buckling Load ◽  
Two Stage ◽  
Element Analysis ◽  
Load Carrying ◽  
Hydraulic Cylinders

The hydraulic cylinder is an actuating mechanical maneuver used to transfer the power from one station to another. For industrial purposes, various types of cylinders are employed as per the requirement. Telescopic hydraulic cylinder, also known as the two-stage hydraulic cylinder is one of the widely used hydraulic cylinders in the industry. The closed center length of a telescopic cylinder is 20% to 40% of the open center length depending on the number of stages. The safe operation of such telescopic hydraulic cylinder is highly essential. One of the prominent failures includes the buckling failure of the hydraulic cylinder. Once the system fails, the operating parameters change abruptly and thus the proper working gets affected. In literature, there is no significant standard that governs the buckling load determination of two-stage hydraulic cylinder. Existing technical standard ISO/TS 13725 : 2016 approach is only prescribed for the single-stage cylinder. In this manuscript, the emphasis is kept upon the determination of the buckling load for the two-stage pin-mounted telescopic hydraulic cylinder. The buckling governing equation has been derived to obtain the buckling load using an analytical approach. Additionally, the stress condition of cylinder barrels of different stages has been discussed per thick cylinder theory. The finite element analysis has been performed for various dimensions of the hydraulic cylinder. The results obtained from analytical results show close vicinity with the finite element results.

scholarly journals Tribological Behavior of Hydraulic Cylinder Coaxial Sealing Systems Made from PTFE and PTFE Compounds

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 155
Author(s):  
Andrea Deaconescu ◽  
Tudor Deaconescu
Keyword(s):  
Film Thickness ◽  
Working Conditions ◽  
Tribological Behavior ◽  
Hydraulic Cylinder ◽  
Current Trends ◽  
Cylinder Piston ◽  
Hydraulic Cylinders ◽  
Fluid Film Thickness ◽  
Selection Of

Current trends concerning hydraulic cylinder sealing systems are aimed at decreasing energy consumption which can be materialized by minimizing leaks and reducing friction. The latest developments in the field of materials and sealing system geometries as well as modern simulation possibilities allow maximum performance levels of hydraulic cylinders. Reducing friction is possible by hydro-dynamic separation of the sliding and sealing points already at very low velocities and by using materials, such as plastomers, from polytetrafluoroethylene (PTFE) (virgin PTFE and filled PTFE). It is within this context that this paper discusses a theoretical and experimental study focused on the tribological behavior of coaxial sealing systems mounted on the pistons of hydraulic cylinders. It presents a methodology for the theoretical determination of the lubricant film thickness between the cylinder piston and the seal. The experimental installation used for measuring fluid film thickness is presented, and the results obtained under various working conditions are compared to the theoretical ones. For the analyzed working conditions related to pressure, speed, and temperature, the paper concludes with a set of criteria for the selection of the optimum seal material so as to maximize energy efficiency.

Kinematic Approximations in TED and RHEED Analysis of Reconstructed Surfaces

1990 ◽  
Vol 48 (2) ◽  
pp. 396-397
Author(s):  
L. -M. Peng ◽  
M. J. Whelan
Keyword(s):  
Electron Diffraction ◽  
Kinematic Analysis ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
Great Success ◽  
High Energy Electron ◽  
Kinematic Approximation ◽  
Reconstructed Surfaces

In recent years there has been a trend in the structure determination of reconstructed surfaces to use high energy electron diffraction techniques, and to employ a kinematic approximation in analyzing the intensities of surface superlattice reflections. Experimentally this is motivated by the great success of the determination of the dimer adatom stacking fault (DAS) structure of the Si(111) 7 × 7 reconstructed surface.While in the case of transmission electron diffraction (TED) the validity of the kinematic approximation has been examined by using multislice calculations for Si and certain incident beam directions, far less has been done in the reflection high energy electron diffraction (RHEED) case. In this paper we aim to provide a thorough Bloch wave analysis of the various diffraction processes involved, and to set criteria on the validity for the kinematic analysis of the intensities of the surface superlattice reflections.The validity of the kinematic analysis, being common to both the TED and RHEED case, relies primarily on two underlying observations, namely (l)the surface superlattice scattering in the selvedge is kinematically dominating, and (2)the superlattice diffracted beams are uncoupled from the fundamental diffracted beams within the bulk.

The Lower Extremity Exoskeleton Coordinated Control Method Based on Human Electromechanical Coupling

2012 ◽  
Vol 220-223 ◽  
pp. 1012-1017
Author(s):  
Qing Guo ◽  
Dan Jiang
Keyword(s):  
Lower Extremity ◽  
Electromechanical Coupling ◽  
Position Control ◽  
Control Method ◽  
Angular Displacement ◽  
Stability Margin ◽  
Hydraulic Cylinder ◽  
Load Force ◽  
Hydraulic Cylinders ◽  
Coupling Characteristics

This paper has introduced electromechanical coupling characteristics in the lower extremity exoskeleton systems, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain exoskeleton boost effect, at the same time, met the needs of human-machine coordinated motion.

Development of hydraulic cylinder diagnostic methods by modeling methods

2021 ◽  
pp. 41-45
Author(s):  
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Technical Condition ◽  
Diagnostic Methods ◽  
Technical Diagnostics ◽  
Remaining Service Life ◽  
Construction Machine ◽  
Piston Speed ◽  
Variable Nature ◽  
Hydraulic Cylinders

The hydraulic drive of a construction machine is a complex dynamic system that is subjected to many dynamic loads of a variable nature and operates under conditions of variable external influences caused by various factors. During operation, these loads cause failure of the hydraulic transmission elements. To prevent these malfunctions, technical diagnostics should be applied by determining their current technical condition and remaining service life. The article assesses the working condition of hydraulic cylinders using a mathematical model. Using matlab/simulink software to simulate the hydraulic cylinder and hydraulic piston speed when changing the hydraulic cylinder clearance. The simulation results are presented. Keywords: diagnostic, hydraulic cylinder, simulation, development

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