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.

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.

Experimentally Validated Models of O-Ring Seals for Tiny Hydraulic Cylinders

2014 ◽  
Author(s):  
Jicheng Xia ◽  
William K. Durfee
Keyword(s):  
Simulation Models ◽  
Hydraulic Cylinder ◽  
Operating Conditions ◽  
System Level ◽  
Needle Valve ◽  
Hydraulic Systems ◽  
System Level Simulation ◽  
Piston Seal ◽  
Cylinder Piston ◽  
Hydraulic Cylinders

To enable simulation of tiny hydraulic systems, including predicting system efficiency, it is necessary to determine the effect of the hydraulic cylinder piston seal. For tiny cylinders whose bore is less than 10 mm, O-ring seals are convenient. Simplified models for the O-ring were used to describe piston leakage and friction and based on the models, the force and volumetric efficiencies for tiny cylinders were predicted for a range of steady state operating conditions. To validate the models, a test stand was constructed to collect experimental data for 4, 6 and 9 mm bore cylinders, which were in the form of a vertical ram with a single O-ring seal. The ram was fully extended and put under load. A needle valve was then cracked to cause the ram to descend at different speeds. Pressure, load and velocity were recorded and the data used to calculate cylinder efficiencies, which were then compared to model predictions. The model and the experiment showed essentially zero leakage. The experimental force efficiency had good agreement with the model over a range of operating conditions. The study showed that simple O-ring models for tiny hydraulic cylinders suffice for building system level simulation models.

scholarly journals STRESSED-DEFORMED STATUS OF THE HANGING HYDROCYLINDER: INFLUENCE OF THE CONJUGATED ELEMENTS’ PAIRS

2020 ◽  
Vol 17 (1) ◽  
pp. 44-56
Author(s):  
D. A. Potakhov
Keyword(s):  
Contact Interaction ◽  
Three Dimensional ◽  
Road Construction ◽  
Hydraulic Cylinder ◽  
Hydraulic Motor ◽  
The Road ◽  
Spatial Design ◽  
Urgent Task ◽  
Cylinder Piston ◽  
Hydraulic Cylinders

Introduction. The contact interaction of the associated elements of the hydraulic cylinder (piston with sleeve, guide sleeve with cylinder and rod) determines the reliability of the reciprocating hydraulic motor. Assessing the effect of gaps of articulated hydraulic cylinder elements is an urgent task in view of the fact that the formation of gaps is inevitable, since friction is always accompanied by tribological wear processes. The paper investigates the determination and assessment of the influence of the gaps of the hydraulic cylinders’ mating elements on the stress-strain state of the contacting bodies on the example of the hydraulic cylinder for the Sokol 80.01 railway crane.Materials and methods. The author used the finite element method implemented in the Simulation SolidWorks module. Moreover, the author applied the Huber–Mises criterion as a criterion for the material plasticity. The paper also considered theoretically possible spatial design schemes of loading and depending on the type of the mating elements’ contacting of the hydraulic cylinder.Results. As a result, the author presented plots and graphical dependences, which were three-dimensional surfaces constructed according to the results of numerical experiments. The calculations took into account the joint deformation of the piston, sleeve, rod, guide sleeve and supporting guide rings of the hydraulic cylinder. The author carried out the analysis of the obtained diagrams and dependences of the contact interaction of the hydraulic cylinder for various options of the elements contacting. The paper presented the results that were useful for studying all types of hydraulic cylinders and working equipment of the road, construction and hoisting-andtransport machines.Financial transparency: the author has no financial interest in the presented materials or methods. There is no conflict of interest.

The Design of Hydraulic Cylinder for Measuring the Contact Stress of the Bud Type Seal Ring

2013 ◽  
Vol 834-836 ◽  
pp. 1365-1368
Author(s):  
Xi Zhang ◽  
Zhi Min Zhao ◽  
Miao Yu ◽  
Yan Yan Wang
Keyword(s):  
Contact Stress ◽  
Detection Method ◽  
Hydraulic Cylinder ◽  
Seal Ring ◽  
Test Cylinder ◽  
Cylinder Piston ◽  
Selection Of

At present, the bud type rings are widely used in the hydraulic cylinder piston rod seal, but there is no corresponding detection method to measure the contact stress when the seals are in the dynamic sealing condition. However, the contact stress is very important for analyzing the performance of the seals. A method for measuring the contact stress is presented in this paper, and the design of major parts of the test cylinder and the selection of seals are emphatically introduced.

scholarly journals The Selection of Hydraulic Cylinder using multi-attribute decision-making methods

2021 ◽  
Author(s):  
Satywan Khatke ◽  
Satyam Fulzele ◽  
Shubham Kadam ◽  
Avinash Kamble
Keyword(s):  
Decision Making ◽  
High Pressure ◽  
Manufacturing Industry ◽  
Hydraulic Cylinder ◽  
Hydraulic Motor ◽  
Current Case ◽  
Hydraulic Cylinders ◽  
Multi Attribute Decision Making ◽  
Selection Methodology ◽  
Selection Of

Abstract A hydraulic cylinder has an important role in the manufacturing industry for producing unidirectional force through the unidirectional direction. Generally, hydraulic cylinders are used where high-pressure applications are required. It is also called a linear hydraulic motor or mechanical actuator. It is manufactured with closer precisions; thus, it involves higher costs and also, it is desired that hydraulic cylinder work as mentioned design. The main purpose of a hydraulic cylinder is to apply force unidirectional with high pressure. The selection of appropriate Hydraulic Cylinders is a critical task for designers. Designers need to find out precise and required properties of it to fulfil industry demand with desired specifications. Different cylinders possess different properties, so by using an optimization tool we can solve such problems. A systematic approach must be used for the selection of hydraulic cylinders. Thus, in current case study work concentrate on the selection methodology for the best Hydraulic cylinder using four different multi-attribute decision-making methods. The decision-making methods help to predict and rank different hydraulic cylinders.

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 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.

Synergy of surface textures on a hydraulic cylinder piston

2019 ◽  
Vol 14 (4) ◽  
pp. 424-429 ◽  
Author(s):  
Ying Zhang ◽  
Liangcai Zeng ◽  
Zhenpeng Wu ◽  
Xianzhong Ding ◽  
Kuisheng Chen
Keyword(s):  
Hydraulic Cylinder ◽  
Surface Textures ◽  
Cylinder Piston
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