The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Ryszard Jasiński - One of the best experts on this subject based on the ideXlab platform.
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PROBLEMS OF THE STARTING AND OPERATING OF Hydraulic ComponentS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF Hydraulic ComponentS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
Polish Maritime Research, 2017Co-Authors: Ryszard JasińskiAbstract:Designers of Hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold Components). In order to put such devices into operation appropriate investigations, including experimental ones - usually very expensive and time-consuming, are carried out. For this reason numerical calculations can be used to determine serviceability of a Hydraulic Component or system operating in thermal shock conditions. Application of numerical calculation methods is much less expensive in comparison to experimental ones. This paper presents a numerical calculation method which makes it possible to solve issues of heat exchange in elements of investigated Hydraulic Components by using finite elements method. For performing the simulations the following data are necessary: ambient temperature, oil temperature, heat transfer coefficient between oil and surfaces of elements, as well as areas of surfaces being in contact with oil. By means of computer simulation method values of clearance between cooperating elements as well as ranges of parameters of correct and incorrect operation of Hydraulic Components have been determined. In this paper results of computer simulation of some experimentally tested Hydraulic Components such as axial piston pump and proportional spool valve, are presented. The computer simulation results were compared with the experimental ones and high conformity was obtained.
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Influence of Type of Material on Performance of Hydraulic Components in Thermal Shock Conditions
Solid State Phenomena, 2011Co-Authors: Ryszard JasińskiAbstract:During the start-up of a Hydraulic system in low ambient temperatures an incorrect operation may occur. The principles and conditions of safely operating Hydraulic driven machines and devices are essential to designers and operators. For this reason the author of this article has conducted a series of tests on Hydraulic Components and systems in thermal shock conditions (cooled-down Components were supplied with hot working medium). In such conditions, the initial parameters of the Hydraulic Components and systems determine their correct operation. During the start-up of a Hydraulic system in thermal shock conditions, elements of Hydraulic Components warm up in a non-uniform way, due to various material properties and shapes of parts. Differences in clearances between elements and may lead to the faulty performance of Hydraulic Components and machine break-down. The selection of appropriate materials for various Hydraulic Component parts should increase machine safety during start-up in thermal shock conditions.
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Influence of Design of Hydraulic Components on their Operation in Low Ambient Temperatures
Key Engineering Materials, 2011Co-Authors: Ryszard JasińskiAbstract:In many machines and devices there are Hydraulic drives. They should operate well in various weather conditions, also in low ambient temperatures. Some malfunctions may occur during operation of Hydraulic system in a so called “thermal shock condition”, which happens when frozen Hydraulic Component (e.g. Hydraulic pump, motor or directional spool valve) is suddenly supplied with hot oil. Transient thermal state emerges in these conditions. Particular elements of Component warm up differently. This results in different thermal expansion of Components during warm up, which is changing the size of clearance between cooperating elements. Experimental tests of Hydraulic Components in low ambient temperatures were conducted in the Hydraulic laboratory of the Faculty of Mechanical Engineering of Gdansk University of Technology. They concerned: orbital motors, satellite motors, gear pumps, spool valves (also proportional), piston pumps, and Hydraulic cylinders. It was proved, that in thermal shock conditions some malfunctions may occur, especially with large temperature differences between oil and Component. Based on results of the tests of Hydraulic Components and systems start-up in low ambient temperatures, one can perform a change in Components design, change the type of material of Components elements, and even prepare a proper procedure to be followed during start-up of cold Hydraulic Components and systems. In the article discusses some designs of Hydraulic Components resistant to thermal shock, and how to prepare Components to work in low temperatures, e.g. by providing system with an additional heater to ensure uniform heating of elements in Components. Change in design of Hydraulic Components resistant to thermal shock conditions can be obtained through computer simulation method. Analytic and computer simulation methods can be used by engineers who design machines and devices that work in low ambient temperatures.
Liu Mei-xia - One of the best experts on this subject based on the ideXlab platform.
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The Lubrication and Seal of Water Hydraulic Component
Mechanical Engineer, 2001Co-Authors: Liu Mei-xiaAbstract:Recently,the Hydraulic system based on water medium is commonly concerned with the former a new task in the field of Hydraulics.The characteristics of lubrication and seal for water Hydraulic Component are de-scribed in this paper,as well as its types of lubrication and seal for water Hydraulic pump in home and abroad.
Yang Yan-ping - One of the best experts on this subject based on the ideXlab platform.
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Analysis and Research on Water Hydraulic Component Material
Journal of Hunan Institute of Engineering, 2004Co-Authors: Yang Yan-pingAbstract:The anti-corrosion and anti-wear properties and applicable conditions of present water Hydraulic Component material are analyzed in accordance with the special requirement of water Hydraulic Components material in water Hydraulic transmission system.The application of QPQ salt bath composite treatment technology applied to water Hydraulic Components is introduced.A new way of choosing material of water Hydraulic Components has been provided.
Bai Ping - One of the best experts on this subject based on the ideXlab platform.
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Experiment Research on New Ceramic Technique for Water Hydraulic Components
Machine Tool & Hydraulics, 2007Co-Authors: Bai PingAbstract:Modern water Hydraulics has been the most important research subject in fluid power.Developing water power Components are the prerequisite for the application.Different kind of pumps and valves for water Hydraulic system has been designed at home and broad by now.A new method to deposit ceramic coating on the surface of Component was introduced based on the analysis of ceramic materials in water Hydraulics.By the using of microarc oxidation technology, a good performance ceramic coating was developed on the surface of a water Hydraulic Component which is made of aluminum.Experiments result shows that there is no strip and corrosion on the ceramic coating from the testing result.This kind of ceramic coating has good wear resistance and it could be applied to improve the performance of water Hydraulic Component.
Liu Shouf - One of the best experts on this subject based on the ideXlab platform.
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Numerical Simulation on Leakage of Straight-through Labyrinth Seals for Hydraulic Cylinder
Machine Tool & Hydraulics, 2013Co-Authors: Liu ShoufAbstract:In order to solve the leakage analysis problem of straight-through labyrinth seals for Hydraulic cylinder,a numerical analysis method was presented,in which k- e turbulent model of incompressible fluid was used to calculate the leakage of the labyrinth seal in piston edge based on PHOENICS software,the influences of groove number,groove depth,groove width and linear velocity on leakage were analyzed. It is shown that under laminar condition,the labyrinth seal not only cannot prevent leaking,but also brings negative influence. Comparing with other methods,the simulation method is more economical and practical,and it supplies valuable reference for Hydraulic Component designer.
