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During the process of curve section or long radius drilling in the horizontal well, between the drilling string and wellbore, the phenomenon of friction, sticking and backing pressure is very serious. The newly developed Hydro-oscillator could make vibration in radial direction and axial ones. So the tool could reduce the sliding friction and increase the effective drilling weight of the bit(WOB)...
The article reviews the design of actuators of vibrations seismic sources, their advantages and disadvantages. The conclusion about the prospects of the elastic sheaths use is made.
To meet the requirements of increasing off-highway vehicle productivity and of higher safety requirements, an improvement on boom/bucket stability of off-high way vehicles has been commanded in industry on multiple platforms. Various control algorithms have been developed to deal with the motion compensation problem. Developing and implementing the controllers directly on a vehicle is challenging...
Tamping devices have a common problem that the amplitude and frequency of the tamping tool cannot be adjusted and, thus, are too inflexible to satisfy different working demands. In order to solve this problem, mathematical modeling and analysis of a new tamping arm are developed according to the technical parameters of the existing tamping devices, and the configuration of the new tamping exciter...
In order to study the dynamic characterization of a new type zero leakage valve with double direction, in this paper, we simplify the model of the new type zero leakage valve with double direction and establish a mathematical dynamic model of single degree of freedom torsion system. Based on the theory, the software of Adams was adopted to establish the dynamic model of virtual prototype, and the...
Molecular techniques are transforming our understanding of cellular function and disease. However, accurate molecular analysis methods will be limited if the input DNA, RNA, or protein is not derived from pure population of cells or is contaminated by the wrong cells. This paper will introduce a design of a micro-to-nano manipulation device. It was an automatic, rapid, accurate separation and extraction...
In order to get an electro-hydraulic vibrator with high frequency, great exciting force and large flow, a new type of rotary valve with four-way commutation was designed. The rotary valve is worked under special environment, so the characteristic of the valve must be studied. Based on the structure and working principle of this valve, the mathematical expressions of steady-state axial flow force and...
A new electro-hydraulic high-frequency flutter generator is designed and simulated. This paper introduced the structure and the working principle of the flutter generator firstly, then established the mathematical model of the generator. From the simulation waveform, the cutting force as the tool to withstand 8000N, the amplitude reaches 6μm, which is fully meet the requirements of VAM, and provide...
New approaches to fairly old noninvasive cardiology tools, based on studying low frequency vibrations created by the heart on the body, were reviewed. These signals were divided and studied in two categories and compared in their capability for estimation of hemodynamic parameters. In particular one representative signal of each category, seismocardiogram and ultra-low frequency ballistocardiogram,...
The requirements of higher train speed, safety and more smooth and comfortable travelLing are increasing strongly. This leads the need of predictive maintenance. Tamping machines have been used for this purpose. Tamping machines on the market are mostly mechanically driven. A new hydrauLically driven tamping device is proposed to overcome the Limitations of mechanically driven machines. A new type...
Active pneumatic vibration isolation system (APVIS) is widely used in IC equipments and high precision metrology devices. Proportional spool valves are normally used as its actuator. However, it exhibits strong non-Linearity, such as dead zone and stick-sLip effect, which results in flux fluctuation, to greatly degrade the vibration isolation performance. In this paper, a dynamic model for air spring...
The damping of a common cabin of a commercial vehicle is realized with hydraulic based dampers integrated inside the air springs of the suspension. For the suspension proposed in this paper, the damping forces are generated by varying the mass of air inside the air spring volume. To achieve a high bandwidth of vibration suppression, the mass flow of compressed air is controlled using fast switching...
This paper is to build a reliable simulation model which is useful for the design of hydro-pneumatic suspension. To get a right simulation model, a test platform based on hydro-pneumatic suspension was set, several damping pores with different sizes are used in the experiment, pressures on both sides of damping pore and force on piston rod were collected. The simulation model of hydro-pneumatic suspension...
An operation mode called hybrid sliding pressure operation mode, which considered the valve point and operation load together, was proposed in this paper based on the analysis and study of a large number of unit operation optimization methods. In addition, according to the steam-excited vibration occurred during the optimization process when the nozzle governing steam turbine switch single valve to...
We discuss an empirical based design of Active Strobe Imager (ASI) that enables us to visualize the dynamic behavior of tissue, even under a high frequency vibration that cannot be followed by the naked eye. A pneumatic actuator imparts a vibration for the target object. By flashing light with slightly different frequency, we can see the dynamics by the naked eye. We discuss an approach for determining...
An excitation means of electrohydraulic vibrator is proposed and aimed to enhance the working frequency. The vibrator is a symmetrical hydraulic cylinder controlled by a 2D valve, in which both rotary and linear motions of a single spool are used to vary the frequency and the amplitude independently. The frequency of the vibrator is proportional to the rotary speed of the spool and thus the high-frequency...
Damping changeability design and evaluation is the most fundamental issue at the beginning of any new semi active hydraulic damper or its control system development. In this study, the changeable damping strategy for the sky-hook control of a rail vehicle semi-active hydraulic damper, which has three parallel orifices, is designed. Fluid formulae for the changeable damping calculation under different...
We present a lumped-parameter dynamic model for a planar poly(dimethylsiloxane) (PDMS) micropump using in-contact, virtually zero-leakage check valves to provide critical insights into the dynamic characteristics of the planar micropump operation. The model features a single-plane microfluidic chamber sandwiched between two check valves, which allows for reliable operation and easy system integration...
This paper presents a novel design for demand dependent active suspension (DDAS) focusing on vehicle rollover control. Active suspensions take credit for improving ride comfort and handling performance, but to use active suspension in vehicle rollover control has not been widely investigated. The proposed active suspension design consists of four double direction hydraulic actuators, hydraulically...
In this paper, we propose a novel master-slave system for micro-manipulation of the mechanical contact type. In the proposed system, suck and blow movements in the master side are scaled and transmitted to the slave side, i.e., we generate the air flow at the tip of the micro-straw in the slave side according to operator's suck and blow in the master side. The air flows by operator's suck and blow...
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