scholarly journals STUDY OF THE EFFECTIVENESS OF VIBRATION ISOLATION OF UNCONVENTIONAL TOROIDAL ROPE VIBRATION ISOLATORS IN DIESEL UNITS VIBRATION ISOLATION SYSTEM

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 110-114
Author(s):  
Minas Minasyan ◽  
Armen Minasyan ◽  
Aung Thant
Keyword(s):  
Power Plants ◽  
Vibration Isolation ◽  
Steel Wire ◽  
Experimental Studies ◽  
Wire Rope ◽  
Diesel Generator ◽  
Isolation System ◽  
Vibration Isolators ◽  
Before And After ◽  
Materials Used

The paper notes that the structure of the wire rope is one of the most suitable materials used as a fire-resistant elastic element of vibration-insulating structures and fasteners (vibration isolators). To solve the problems of vibration isolation of marine diesel power plants in the framework of development and improvement of the shock absorption system, the original patented elastic supports with elastic elements made of steel wire rope in the form of a torus are presented. When commercially available vibration isolators do not meet the relevant requirements of vibration protection of a particular object, the solution to the existing problem can be achieved by using the proposed wire rope vibration isolators. The technical results of the original patented inventions are: - equal stiffness in the horizontal plane - ensuring the reliability and high vibration efficiency of protection against impacts and shocks. The proposed designs of vibration isolators are easy (technological in manufacturing) to manufacture and assemble, reliable and durable - the service life is 10 years or more. Vibration efficiency is confirmed by the vibration acceleration spectra before and after the vibration isolator of the damping system of the ship diesel-generator DGA-500 and the diesel unit with a 2H 8.5/11 engine and water brake on a common sub-frame. The three-year trial life of the DGA-500 and experimental studies on a diesel unit with a 2H 8.5/11 engine and water brake on a common sub-frame confirms their efficiency and effectiveness.

scholarly journals INCREASED VIBRATION ON REFRIGERATOR SHIPS OF B437/11 PROJECT AND TECHNICAL PROPOSALS ON ITS REDUCTION

2018 ◽  
pp. 58-69
Author(s):  
Minas Armenakovich Minasyan ◽  
Aung Myo Thant ◽  
Armen Minasovich Minasyan
Keyword(s):  
Service Life ◽  
Vibration Isolation ◽  
Steel Wire ◽  
Modern Technology ◽  
Wire Rope ◽  
Diesel Generator ◽  
Vibration Isolators ◽  
Wide Range ◽  
Isolation Systems ◽  
The Impact

The paper considers the causes of increased vibration of four auxiliary diesel-generator sets of "Sulzer" 5АL25 type on board nine refrigerated vessels of B437 / 11 project after 15 years of operation. The proposed wide range of possible applications to address the problem of high vibration of diesel generators and motor vessels there were generally implemented upgraded turbocharger brackets, engine sub-frame and supporting spiral-rope vibration isolators in the shock absorption system of the diesel-generator. Four original patented technical solutions have been presented, among which one solution is implemented in 5AL25 diesel generator and 2H 8.5/11 diesel damping systems. There has been offered wide application both wire rope vibration isolators and combined isolators, in which elastic elements are made of nonflammable materials. Wire rope vibration isolators combine high bearing capacity (static loads within 1 N - 50 kN) with high elasticity under dynamic effects; their natural frequencies can drop to 2.5 Hz. Under the worst conditions 75% of the free moving weakens the impact to values that ensure the necessary safety of the object. Experience in designing vibration isolation systems allows to set the maximum range of loads within 15 - 25 g. The vibration isolators made of steel wire rope are practically not affected by the environment, they are made of stainless steel. They effectively operate at temperatures -200°C - +370°C in the presence of oil, dirt, sand, salt fog, etc. They usually have a service life comparable with the service life of the insulated object. Wire rope vibration isolators and combined vibration isolators can be used in all fields of modern technology: shipbuilding, power engineering, automotive, aviation and space industries, etc.

STUDY OF THE VIBRATION ISOLATION SYSTEM OF MARINE POWER PLANTS WITH A 5AL 25/30 DIESEL DRIVE

Akustika ◽  
2021 ◽  
pp. 112
Author(s):  
Minas Minasyan ◽  
Armen Minasyan ◽  
Kyaw Thet Naing
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Power Plants ◽  
Vibration Isolation ◽  
Field Studies ◽  
Absorption System ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
The Impact

The article is devoted to the study of the support and side stop vibration isolation system of two marine power plants DGA- 500 with a 5AL 25/30 drive diesel engine, in which a hypothesis is put forward about the imperfection of the shock absorption system. The purpose of the research is to substantiate the imperfection of the support and side stop vibration isolation system of marine power plants with a 5 AL 25/30 drive diesel engine. The confirmation of this hypothesis and the achievement of this goal is justified on the basis of presentation of the results of field studies on the project’s courts B437/11 and the personal presence during the preparation of DGA-500 to repair at the shipyard. For the use of unbalanced engines as a drive for ship power plants, the authors, on the basis of a full-scale experimental study and analysis of known works, recommend initially assessing the possibility and purpose of depreciation of the unit according to the Katz unbalance criterion [1]. The objective of fixing the unit with diesel 5AL 25/30 on the criterion of imbalance Katz is soundproof, and the calculation of depreciation should be based on the impact of side stop vibration isolators. A significant improvement is recommended to the support 36-40 and side stop 41-52 vibration isolation system, elastic pipe fittings 8, support frame 2 and turbocharger bracket 4 (Fig. 1).

Design and analysis of a vibration isolation system with cam–roller–spring–rod mechanism

2021 ◽  
pp. 107754632110005
Author(s):  
Yonglei Zhang ◽  
Guo Wei ◽  
Hao Wen ◽  
Dongping Jin ◽  
Haiyan Hu
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Experimental Studies ◽  
Excitation Amplitude ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Stiffness Characteristic ◽  
Negative Stiffness Mechanism ◽  
Isolation Systems ◽  
Vibration Isolation Performance

The vibration isolation system using a pair of oblique springs or a spring-rod mechanism as a negative stiffness mechanism exhibits a high-static low-dynamic stiffness characteristic and a nonlinear jump phenomenon when the system damping is light and the excitation amplitude is large. It is possible to remove the jump via adjusting the end trajectories of the above springs or rods. To realize this idea, the article presents a vibration isolation system with a cam–roller–spring–rod mechanism and gives the detailed numerical and experimental studies on the effects of the above mechanism on the vibration isolation performance. The comparative studies demonstrate that the vibration isolation system proposed works well and outperforms some other vibration isolation systems.

A Variable Stiffness Vibration Isolation System Based on Magneto-Rheological Elastomer

2012 ◽  
Vol 452-453 ◽  
pp. 659-662
Author(s):  
Wei Wang ◽  
Yi Min Deng
Keyword(s):  
Shear Modulus ◽  
Vibration Isolation ◽  
Variable Stiffness ◽  
Control Area ◽  
Frequency Range ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Magneto Rheological ◽  
Conventional Type

Vibration isolation is a most widely used vibration protection method.The stiffness of vibration isolators in existing conventional type of vibration isolation system is usually of fixed value. This limits the system in exhibiting its vibration isolation effect in that, it has poor results for lower frequency vibration, especially for resonance frequency. Magneto-rheological elastomer is a new branch of Magneto-rheological materials. It’s an intelligent materials in that it’s shear modulus can be controlled by a magnetic field. It has wide application prospects in the vibration control area. This paper proposes using adjustable stiffness of magneto-rheological elastomer vibration isolation in vibration isolation system. By changing the current of vibration isolators coil to control the shear modulus of magneto-rheological elastomer, it can adjust the stiffness of the isolation system, making the system obtain wider vibration isolation frequency range. By exploying SimuLink software to analyze the vibration isolation system, it is found that such a design is effective and applicable.

Method of experimental evaluation of the efficiency coefficient of vibration protection of the rope-rod coupling "MAMSAR+A" of the diesel generator set DGA-8.83

2021 ◽  
pp. 88-95
Author(s):  
М.А. Минасян ◽  
А.М. Минасян ◽  
Ц. Цзэн
Keyword(s):  
Experimental Evaluation ◽  
Vibration Isolation ◽  
Experimental Studies ◽  
Original Method ◽  
Efficiency Coefficient ◽  
Diesel Generator ◽  
Vibration Protection ◽  
Rigid Connection ◽  
Two Stages

Объектом исследования является опытный образец запатентованной канатностержневой муфты (КСМ) «MAMSAR+А» в качестве привода дизель-генераторного агрегата ДГА-8,83 мощностью 9,56 кВт при частоте вращения 1500 мин-1 с дизелем 2Ч 8,5/11 и генератором «ГК-5,6». Целью исследования является экспериментальная оценка коэффициента эффективности вибрационной защиты КСМ. Поставленная цель достигается разработкой и реализацией оригинальной методики экспериментальной оценки коэффициента эффективности КСМ с анализом и выводами результатов экспериментальных исследований. Экспериментальные исследования проводятся в два этапа. Первый этап – с упругим соединением КСМ, второй этап – с жестким соединением. Оригинальность методики экспериментальной оценки коэффициента эффективности вибрационной защиты КСМ главным образом заключается в том, что между двумя этапами экспериментальных исследований КСМ не демонтируется. Следовательно, качество центровки не нарушается. Усредненный коэффициент эффективности виброизоляции КСМ составляет от 3 до 8 дБ. The object of this research is a prototype of the patented wire rope coupling (KSM) "MAMSAR+A" as a drive for a diesel-generator unit DGA-8.83 with a power of 9.56 kW at a speed of 1500 min-1 with a 2CH 8.5/11 diesel engine and a generator "KG-5.6". The aim of the research is to experimentally evaluate the efficiency coefficient of vibration protection of the KSM. This goal is achieved by developing and implementing an original method for experimental evaluation the efficiency coefficient of the KSM with analysis and conclusions of the results of experimental studies. Experimental studies are conducted in two stages. The first stage - with an elastic connection of the coupling, the second stage - with a rigid connection. The originality of the method of experimental evaluation of the efficiency coefficient of vibration protection of the KSM mainly lies in the fact that the KSM is not dismantled between the two stages of experimental research. Therefore, the quality of alignment is not violated. The average coefficient of vibration isolation efficiency of the KSM is from 3 to 8 dB.

scholarly journals Reconstruction of Input Excitation Acting on Vibration Isolation System

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Pan Zhou ◽  
Wen L. Li ◽  
Wanyou Li ◽  
Zhijun Shuai
Keyword(s):  
Vibration Isolation ◽  
Mechanical Design ◽  
Spectral Density Function ◽  
Dynamic Responses ◽  
Accurate Estimation ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Supporting Structure ◽  
Vibration Prediction

Vibration isolation systems are widely employed in automotive, marine, aerospace, and other engineering fields. Accurate input forces are of great significance for mechanical design, vibration prediction, and structure modification and optimization. One-stage vibration isolation system including engine, vibration isolators, and flexible supporting structure is modeled theoretically in this paper. Input excitation acting on the vibration isolation system is reconstructed using dynamic responses measured on engine and supporting structure under in-suit condition. The reconstructed forces reveal that dynamic responses on rigid body are likely to provide more accurate estimation results. Moreover, in order to improve the accuracy of excitation reconstructed by dynamic responses on flexible supporting structure, auto/cross-power spectral density function is utilized to reduce measurement noise.

scholarly journals Vibration Test and Shock Absorption of Coal Crusher Chambers in Thermal Power Plants (I): Field Test and Assessment

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lihua Zhu ◽  
Hanquan Yuan ◽  
Haoyi Zhou ◽  
Dong Jiang ◽  
Baoquan Liu ◽  
...  
Keyword(s):  
Power Plants ◽  
Vibration Isolation ◽  
Thermal Power ◽  
Vibration Test ◽  
Thermal Power Plants ◽  
Test Results ◽  
Vibration Displacement ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Performance

A field vibration test was conducted on the coal crusher chamber of a thermal power plant to evaluate its vibration performance. The vibration displacements and velocities of the structure, coal crusher body, and vibration-isolation platform were tested. The vibration safety of the coal crusher chamber and the vibration-isolation efficiency of the spring vibration-isolation system were evaluated based on the test results, and the reason the vibration exceeded the limit was analyzed. This study showed that the vibration displacement of a coal crusher with a spring vibration-isolation system met the code requirements, but the equipment had greater vibration displacements, which were related to the connection between the equipment and the platform. Compared to a steel platform, the vibration displacement of a concrete platform was smaller, and the vibration-isolation efficiency was greater. The vibration displacements of the coal crusher body could be reduced by controlling the vibration displacements of the platform.

Active Vibration Isolation System Using the Piezoelectric Unimorph With Mechanically Pre-Stressed Substrate

2010 ◽  
Author(s):  
Dae-Oen Lee ◽  
Lae-Hyong Kang ◽  
Jae-Hung Han
Keyword(s):  
Vibration Control ◽  
Vibration Isolation ◽  
Load Capacity ◽  
Active Vibration Control ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Before And After ◽  
Active Vibration ◽  
Piezoelectric Unimorph ◽  
Active Vibration Isolation

In this paper, a pre-stressed piezoelectric unimorph made by a new fabrication method in room temperature, and an active vibration isolation system using the pre-stressed unimorph actuators are introduced. The fabricated piezoelectric unimorph, called PUMPS (piezoelectric unimorph with mechanically pre-stressed substrate), is an actuator in which actuation level is enhanced by displacement amplification mechanism that converts piezoelectric extension and contraction to large bending/pumping motion without sacrificing the actuation force. Preliminary vibration tests were performed to check the performance of PUMPS as actuators for active vibration control in a lab environment. Two feedback control schemes, the positive position feedback (PPF) and negative velocity feedback (NVF), were applied for active vibration control. Using a smart vibration isolation system with improved load capacity obtained by stacking pre-stressed piezoelectric unimorph actuators, about 10dB vibration reduction of the system was achieved near the resonant frequency region. With the preliminary vibration test results showing promising performance of PUMPS actuator in active vibration control, an integrated active vibration isolation system composed of PUMPS actuators is developed. The developed system contains compact analogue circuits and a sensor for PUMPS actuation and control, and power is supplied by Li-Polymer battery which means the system is completely standalone and portable. In addition, an integrated jitter isolation demonstration system was developed to demonstrate the degrading effect of jitter and the effectiveness of the developed integrated active vibration isolation system in improving the performance of optical payloads. Comparison of image qualities taken before and after the operation of vibration control system indicates that effective suppression of vibration disturbances can be achieved using the developed vibration isolation system with PUMPS actuators.

Dynamic Analysis of Nonlinear Vibration Isolation System Based on Flexible Foundation

2014 ◽  
Vol 1030-1032 ◽  
pp. 766-769
Author(s):  
Shu Ying Li ◽  
Rui Huo ◽  
Xing Ke Cui ◽  
Cui Ping Liu ◽  
Dao Kun Zhang
Keyword(s):  
Nonlinear Vibration ◽  
Power Flow ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Coupled System ◽  
Optimized Design ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Vibration Isolators ◽  
Flexible Foundation

In this paper,a general dynamic model of the isolation coupled system which is composed of isolation object,nonlinear vibration isolation support,and flexible foundation is established,calculated method of applying vibration power flow to analyze isolation effectiveness is studied.Further more,as an calculation example,a air spring vibration isolation system of HS-700 engines is numerically simulated.Designs several low-frequency nonlinear vibration isolators and analyzes its vibration isolation effect.It discusses the effect of the vibration isolator parameters on the transmitted power flow of the system.The results provide a theoretical basis for the optimized design of nonlinear vibration isolation system.

Research on Active Vibration Isolation System for Precision Instrument Based on Four Piezoelectric Stack Actuators

2010 ◽  
Vol 44-47 ◽  
pp. 1034-1038
Author(s):  
Qing Song Cao ◽  
Yun Yun Hong
Keyword(s):  
Smart Materials ◽  
Vibration Isolation ◽  
Piezoelectric Materials ◽  
Rapid Development ◽  
Precision Instrument ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
Materials Used ◽  
Active Vibration Isolation

With the rapid development of smart materials, piezoelectric materials used as actuators in vibration isolation platform have been widely applied in precision machining, precision measurement and precision positioning, etc. This paper investigates active vibration isolation system of precision instrument based on four piezoelectric stack actuators, which is consisted of four bases, four piezoelectric stack actuators and precision instrument. Piezoelectric stack actuators are laid between the bases and precision instrument as active isolation components to suppress the vibration from the vibrating bases. Model of the active vibration isolation system is derived based on Newton's second law. Then the active controller is designed with LQR control algorithm. The simulation using MATLAB software show that this method is feasible and LQR controller designed can effectively suppresses the vibration of precision instrument.

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