Design of a new mechanism for jetting dispenser featuring piezoactuator

Author(s):  
Q H Nguyen ◽  
Y M Han ◽  
S B Choi ◽  
S M Hong

This work presents both the static and dynamic models for a new type of jetting dispenser featuring a piezostack actuator, which is applicable to electronic packaging assembly. After describing the configuration of the dispensing mechanism and operational principle of the proposed piezostack-driven jetting dispenser, a static modelling for mechanical part is analysed by considering the piezostack behaviour, fluid compressibility, and structural deflection. Both linear and non-linear behaviours of the structural plate are analysed and incorporated. The dynamic modelling of the mechanical part is also performed by considering the dynamic behaviour of the piston and needle. After optimizing the design parameters, such as piston radius and so on, the behaviour of the needle motion is obtained and checked for adhesive dispensing applicability. In order to demonstrate the effectiveness of the proposed static and dynamic models, an experimental test is undertaken by showing needle displacement.

2019 ◽  
Vol 287 ◽  
pp. 01018 ◽  
Author(s):  
Nikolaos Rogkas ◽  
Georgios Vasileiou ◽  
Efstratios Tsolakis ◽  
Vasileios Spitas ◽  
Pavlos Zalimidis

In recent years multidisc wet friction clutches are of great importance to manufacturers of automatic transmissions (ATs) for the automotive industry, particularly since the introduction of double-clutched ATs. Their main advantage compared to their dry-friction counterparts is that they ensure smooth engagement, high reliability and long service life. Their progressive engagement due to the developed Couette flow between the discs enables them to be used both as clutches and as brakes in order to control power flow in simultaneously engaged geared shafts in the AT. Due to the coupled nature between the mechanical and the fluid dynamics regimes governing their operation, these systems are highly complex to be treated analytically and instead numerical approaches have proven to provide better results. However, the numerical treatment of such problems provides only case-specific results, which cannot be generalised and are not able to provide a general insight in the complex dynamics of the device. Furthermore the computational cost and the associated modelling and simulation effort during the design phase is high, making the incorporation of such methods in iterative design processes and algorithms counterproductive. In this paper the modelling of the dynamic behaviour of a wet multidisc clutch during the engagement phase is performed, via the combination of analytical and numerical methods and conclusions are drawn about the effect of the main geometric, kinematic and dynamic design parameters on the clutch’s response. The dynamic modelling is performed by applying the principle of linear and angular momentum on each disc. The effect of the fluid film is taken into account through the solution of the governing Navier-Stokes equations via CFD analysis or by the use of semi-analytical solutions with high accuracy, where applicable. Therefore both the developed pressure field and the torque of the fluid film are calculated efficiently and used in the simulation of the system. The flow is assumed to be laminar and the discs rigid and flat.


Author(s):  
Pengfei Yuan ◽  
Baiyan He ◽  
Lianhong Zhang

Round link chain drives can be sorted into the transmission, parallel conveyor and non-parallel conveyor systems according to their applications and guide rail’s layouts. The polygonal action in these systems is irregular. Compared with the literature, this paper proposes a more accurate modelling approach to capture the dynamic behaviour of round link chain drives, which can consider both the irregular polygonal action and non-parallel guide rail’s layout. The dynamic models of the three types of round link chain drives are developed based on the finite segment method. The chain is divided into multiple discrete segments that are connected by Kelvin models. To account for the irregular polygonal action, the sprocket is equivalent to an irregular polygon. To consider the non-parallel guide rail’s layout in the conveyor system, the chain segment out of the guide rail and the corresponding sprocket are treated as a swinging-block mechanism. The proposed approach is applied to model a scraper conveyor. Simulation results show that the irregular polygonal action and non-parallel guide rail’s layout greatly increase the fluctuation of the chain tension force.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Hengqing Tian ◽  
Dimitrios Tzelepis ◽  
Panagiotis N. Papadopoulos

Electric Vehicles (EVs) are becoming increasingly available and are expected to be a large part of the load in future power systems. EV chargers are a relatively new type of load and are mainly interfaced with the grid through power electronics. It is therefore important to investigate the impact they have on power system dynamic behaviour. In this paper, two detailed EV charger models (representing a typical slow and fast charger) were investigated. The aim was to test the capability of standard static—and more importantly, dynamic—load models, commonly used in power system studies, to represent the static and dynamic behaviour of EV chargers. Different control parameter settings for two types of EV chargers were investigated, as were the limits of standard power system dynamic load model structures’ accurate representation. Typical parameter sets have also been provided for cases where proper representation was possible.


Author(s):  
Oluwole K. Bowoto ◽  
Omonigho P. Emenuvwe ◽  
Meysam N. Azadani

AbstractThis study proposes a design model for conserving and utilizing energy affordably and intermittently considering the wind rush experienced in the patronage of renewable energy sources for cheaper generation of electricity and the solar energy potential especially in continents of Africa and Asia. Essentially, the global quest for sustainable development across every sector is on the rise; hence, the need for a sustainable method of extracting energy cheaply with less wastage and pollution is on the priority list. This research, integrates and formulates different ideologies, factors and variables that have been adopted in previous research studies to create an efficient system. Some of the aforementioned researches includes pumped hydro gravity storage system, Compressed air gravity storage system, suspended weight in abandoned mine shaft, dynamic modelling of gravity energy storage coupled with a PV energy plant and deep ocean gravity energy storage. As an alternative and a modification to these systems, this research is proposing a Combined solar and gravity energy storage system. The design synthesis and computational modelling of the proposed system model were investigated using a constant height and but varying mass. Efficiencies reaching up to 62% was achieved using the chosen design experimental parameters adopted in this work. However, this efficiency can be tremendously improved upon if the design parameters are modified putting certain key factors which are highlighted in the limitation aspect of this research into consideration. Also, it was observed that for a test load of 50 × 103 mA running for 10 h (3600 s), the proposed system will only need to provide a torque of 3.27Nm and a height range of 66.1 × 104 m when a mass of 10 kg is lifted to give out power of 48 kwh. Since gravity storage requires intermittent actions and structured motions, mathematical models were used to analyse the system performance characteristics amongst other important parameters using tools like MATLAB Simscape modelling toolbox, Microsoft excel and Sysml Model software.


2011 ◽  
Vol 71-78 ◽  
pp. 4634-4637
Author(s):  
Tian Lin Cui ◽  
Jing Kun Pi ◽  
Yong Hui Liu ◽  
Zhen Hua He

In order to optimize the design of flexible pressurized anchor, this paper gives a further analysis on structural features of the new type of flexible pressurized anchor and carries out a contact analysis on anchor system by using the finite element method. It calculates as well as researches the contact stress relation of interactional anchor rod and surrounding rock under the circumstance of anchoring, obtaining the law of all major design parameters of anchor rod structure and pressure from surrounding rock influencing the anchoring performance and arriving at the conclusion that the anchor rod is adapted to various conditions of surrounding rock. They not only serve as important references for optimized design and application of anchor rod, but also provide a basis for the experiment of new type of anchor rod.


Author(s):  
Hashem Ashrafiuon

Abstract This paper presents the effect of foundation flexibility on the optimum design of vibration absorbers. Flexibility of the base is incorporated into the absorber system equations of motion through an equivalent damping ratio and stiffness value in the direction of motion at the connection point. The optimum values of the uncoupled natural frequency and damping ratio of the absorber are determined over a range of excitation frequencies and the primary system damping ratio. The design parameters are computed and compared for the rigid, static, and dynamic models of the base as well as different levels of base flexibility.


Author(s):  
Tingting Wei ◽  
Dengji Zhou ◽  
Jinwei Chen ◽  
Yaoxin Cui ◽  
Huisheng Zhang

Since the late 1930s, gas turbine has begun to develop rapidly. To improve the economic and safety of gas turbine, new types were generated frequently by Original Equipment Manufacture (OEM). In this paper, a hybrid GRA-SVM prediction model is established to predict the main design parameters of new type gas turbines, based on the combination of Grey Relational Analysis (GRA) and Support Vector Machine (SVM). The parameters are classified into two types, system performance parameters reflecting market demands and technology development, and component performance parameters reflecting technology development and coupling connections. The regularity based on GRA determines the prediction order, then new type gas turbine parameters can be predicted with known system parameters. The model is verified by the application to SGT600. In this way, the evolution rule can be obtained with the development of gas turbine technology, and the improvement potential of several components can be predicted which will provide supports for overall performance design.


2011 ◽  
Vol 299-300 ◽  
pp. 936-939
Author(s):  
Li Xu ◽  
Liang Yang ◽  
Zhi Hui Shi

The multi-facet drill shows good performance during materials are difficultly machined. However, for a new type of the drilling point, the grinding has been the main problem that restricts its application. To properly grinding the drill point confirms the design parameters, the relationship between design parameters and grinding parameters must be resolved. The mathematical model is the key to solve this problem. In this paper, according to the design of the high manganese steel drilling tool, a mathematical model has been established by the plane grinding method to solve grinding parameters, and to achieve improved mechanical grinding of drill point.


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