The sealing of the high-pressure pump is carried out by means of a seal between the pump drive shaft and the front plate to keep the fuel inside them. The literature presents numerous studies carried out on how these ...
The sealing of the high-pressure pump is carried out by means of a seal between the pump drive shaft and the front plate to keep the fuel inside them. The literature presents numerous studies carried out on how these seals last in time and on their composition. Due to the fact that during assembly or during the mounting of the pump on the engine may occur accidental defects on the sealing area, our interest in this paper is to investigate their impact on pump operation. The damages were explored on a test bench a certain number of kilometres and later analysed their impact on the pump using an ultraviolet chamber in a dark room. The experimental analyses were carried out using the EvoCam optical microscope, but also with the help of computer tomography procedure.
Nowadays, 3D printing (3DP) has become a popular personal approach as it being able to produce a product more quickly and increased accessibility. 3DP was also known as Rapid Prototyping (RP) where it builds three-dim...
Nowadays, 3D printing (3DP) has become a popular personal approach as it being able to produce a product more quickly and increased accessibility. 3DP was also known as Rapid Prototyping (RP) where it builds three-dimensional (3D) products using layer by layer method from a Computer Aided Design (CAD) files. However, dimensional accuracy (DA) was one of the major problems of these technologies. Thus, it is important to evaluate the best parameter in order to find out the best adjustment to avoid the dimensional error. The objectives of this study were to find the best parameter setting and to evaluate the influence of the changing parameter in 3D part shrinkage error. This study only focused on desktop 3D printer machines, which was the Odyssex Designex X2 and the material used was Acrylonitrile Butadiene Stryrene (ABS). In investigate which factors that most significant to shrinkage, DOE approach was used with parameters such as layer thickness (LT), nozzle temperature (NT), print speed (PS), infill density (ID) and bed temperature (BT). Minitab software has been used for analysis purposes. The significant process parameter effect and the best setting of parameter were determined from ANOVA, Main Effect Plot (MEP) and regression method. Finally, from the results of this study, BT was the most significant effect to shrinkage (SK) and the best setting for achieving less value in SK in ABS materials was LT = 0.25mm, NT = 235°C, PS = 55mm/s, ID = 25% and BT = 100°C. The validation runs was conducted based on the best setting value and it shows that the different between predicted value and actual value was 2.56%. This means that the model was reasonably accurate and the best parameter setting was highly recommended. The results also proved the quality of products was improved by using the DOE approach.
Nowadays, most engines which equip agricultural machines, ships and cars are diesel ones with a common-rail high-pressure direct injection system. They are providing the advantages of fuel economy, low emission level,...
Nowadays, most engines which equip agricultural machines, ships and cars are diesel ones with a common-rail high-pressure direct injection system. They are providing the advantages of fuel economy, low emission level, and reduced noise in comparison to conventional direct or indirect injection systems. The heart and the most stressed part of the common-rail system is the high-pressure fuel pump which is driven by the engine camshaft, and its role key is to compress the fuel at pressures over 2000 bar. The high-pressure fuel is delivered from pump to the engine combustion chamber via high rail pipes, high-pressure accumulator (rail) and injectors. Compressing the fuel and sending it towards high-pressure accumulator (rail), in some specific cases the pump generates an audible disturbing noise that gets louder than the engine combustion noise. The paper first offers an overview of our experiments performed on common-rail high-pressure fuel pumps in order to find the noise contributor and to develop measures to reduce the disturbing noise. The experimental investigations have proved that the noise occurs when the fuel is compressed and the outlet valve is opening. Then, our experimental study focuses on outlet valve behaviour from design and noise emissions point of view at idle engine speed.
This paper aims to fabricate functionally graded dental crown using a multi-slurry tape casting additive manufacturing technology. The different luminescence of the dental crown was obtained with different composition...
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作者:
D ZaharieaC M HusaruD E HusaruFluid Mechanics
Fluid Machinery and Fluid Power Systems Department 'Gheorghe Asachi' Technical University of Iasi Iasi Romania Mechanical Engineering
Mechatronics and Robotics Department 'Gheorghe Asachi' Technical University of Iasi Iasi Romania
In this paper a power supply system based on a 10-kW wind turbine on-grid connected used for two different consumers is analysed. The proposed wind turbine site is located at coordinates 46°57'41'N 25...
In this paper a power supply system based on a 10-kW wind turbine on-grid connected used for two different consumers is analysed. The proposed wind turbine site is located at coordinates 46°57'41'N 25°56'36' E, in the Ceahlau National Park, on the plateau of Ceahlau Mountain. Nearby there are located the two consumers: the Ceahlau Monastery and the Dochia Chalet. The site wind resource is obtained mainly from NASA Surface meteorology and Solar Energy database. The load demand curves, the annual energy consumption and the peak load are obtained considering the standard load profile for these two particular types of consumers. The on-grid power supply system is analysed using HOMER Energy microgrid modelling software for different tourist's occupancy. Two different wind turbines (XZ and XL) with rated power of 10 kW are comparatively analysed. Selection of the most suitable wind turbine is realized using the Weighted Product Method (WPM), for which nine attributes are used: annual energy production, capacity factor, renewable fraction, grid purchase, grid sales, initial investment, net present cost, levelized cost of energy, and simple payback. For a given criteria weights, the XL model is found to be the most suitable wind turbine.
The high-pressure pump is a component of the automotive common-rail system and has as main assemblies: housing, driveshaft, gaskets and front plate. Literature presents analyses of the threaded fastening assemblies, e...
The high-pressure pump is a component of the automotive common-rail system and has as main assemblies: housing, driveshaft, gaskets and front plate. Literature presents analyses of the threaded fastening assemblies, especially for those with the critical joints with screws, those involving torque and angle. The assembly process that we have studied performs the sealing of the components with the gasket through the screws, thus preventing the fuel from leaking from the pump. Our paper presents an analysis of the influence of the tightening process with screws of the housing, gasket and front plate. The experiment was conducted using the Zeiss measuring system and the screwdriver Janome. The tests analysis demonstrates that screwing process can influence the distortion.
The paper presents a method for finding the characteristics of rolling friction between two cylindrical external surfaces. By choosing the motion between two parallel cylinders it results that a point from one of the ...
The paper presents a method for finding the characteristics of rolling friction between two cylindrical external surfaces. By choosing the motion between two parallel cylinders it results that a point from one of the cylinders describes a hyper-cycloidal curve when rolling over the other cylinder. The study is focused on the friction in ball bearings. Parts of the ball bearings to be studied are directly involved in materializing the hyper-cycloidal contact. Thus, the immobile circles are materialized by the outer surface of the external ring and the mobile circles are materialized by the spherical surfaces of the balls. The motion of a laser stick attached to the pendulum is filmed. Analyzing the movie, the numerical time dependence of angular amplitude decrease is obtained. The concordance between the experimental and theoretical angular amplitude damping directs to the value of coefficient of rolling friction.
— Robotic grasping in the open world is a critical component of manufacturing and automation processes. While numerous existing approaches depend on 2D segmentation output to facilitate the grasping procedure, accura...
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This article presents a survey on a Head/Neck mechanism adapted for humanoid robot are studied, humanoid robots require more humanly motion of the head/neck motions to make human comfortable while interacting. The hum...
This article presents a survey on a Head/Neck mechanism adapted for humanoid robot are studied, humanoid robots require more humanly motion of the head/neck motions to make human comfortable while interacting. The humanoid robot head is incorporated with vision and other sensory receptors to provide feedback of the environment; it is essential to stabilize the head positioning while the robot is commuting. Desynchronized feedback from the vision sensors might lead the robot to collide and damage the system. Hence, for synchronized head/neck motions, sustain the load of robot head, and for positioning and orientation of a humanoid robot head a standalone mechanism is required to address these complications.
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