scholarly journals DIRECTIONS OF IMPROVING THE EFFICIENCY OF VIBRATION TECHNOLOGICAL MACHINES

Author(s):  
Oleg Omelyanov ◽  
Mykhailo Zamriі

The article considers the directions of increasing the efficiency of vibrating technological machines. The processing of information on the development of vibration technologies is quite diverse and is represented by numerous scientific and technical developments related to improving the efficiency of vibration machines and ensuring the reliability of their work. The analytical basis for previous research in the creation of new technology are mathematical models that reflect the properties of mechanical oscillatory systems with several degrees of freedom, which perform small oscillations under the action of a system of periodic external perturbations that create vibration fields of one configuration. The dynamic properties of the working bodies of machines in a detailed form are revealed as the distribution of the amplitudes of oscillations of the points of the working bodies. In many cases, this distribution is linear, which is due to the manifestations of the properties of the simplest movements of the working bodies. Approaches are proposed in which the possible structural mathematical modeling is realized on the idea that a linear mechanical oscillatory system with concentrated parameters and several degrees of freedom can be compared with the structural scheme of the automatic control system. Particular attention is paid to the study and evaluation of the possibility of new dynamic effects associated with the simultaneous action of several working bodies of machines, as well as - modes of dynamic damping of oscillations. An important role in ensuring such developments is played by areas of research focused on the development of methods of mathematical modeling. Based on the research it is shown that the vibration field of the vibrating technological machine is formed under the influence of several factors, which are determined by the simultaneous action of several force perturbations, asymmetry of inertial and elastic properties of the mechanical system, the presence of additional connections. The introduction of additional links in the structure of the mechanical oscillating system of the vibrating machine, can significantly affect the structure of the vibration field, providing the choice of conditions for rational organization of the technological process of vibration processing, such as vibration hardening, crushing, transportation, screening.

2017 ◽  
Vol 2017 (1) ◽  
pp. 290-301 ◽  
Author(s):  
Андрей Николаев ◽  
Andrey Nikolaev ◽  
Владимир Кашуба ◽  
Vladimir Kashuba ◽  
Сергей Елисеев ◽  
...  

A method of dynamic vibration damping in mechanical oscillatory systems with several degrees of freedom is offered. The mathematical model of the system is represented in the form of structural scheme the equivalent in a dynamic relation to the automatic control system. The system contains device for con-verting the motion in the form of lever mechanisms containing focused additional masses. The possibilities of changing the dynamic properties of the system by using lever mechanisms and the additional ties in the form of gear connections of the elements system are shown. A method of constructing mathematical models and technology analysis of dynamic properties at kinematic excitation of system is proposed. The system of evaluation of the dynamic properties of the system in regimes of dynamic vibration damping simultaneously on two coordinates based on the use of transfer functions and analysis of structural scheme is offered. The results of computational modeling are given, confirming the manifestation the effects of dynamic blocking of external influences.


2018 ◽  
Vol 2018 (7) ◽  
pp. 44-55
Author(s):  
Куанг Выонг ◽  
Kuang Vyong

The paper reports the consideration of technolo-gical vibrating machine dynamic properties on the ba-sis of the model as a mechanical oscillating system with two degrees of freedom having in its structure a device for motion conversion (DMC) forming addi-tional inertial couplings at the simultaneous action of two external harmonic factors. The purpose of investi-gations consists in the development of the method for the formation of simulators ensuring possibilities for dynamic states assessments at the use of such parame-ters of a state as a relation of ties dynamic reactions between a supporting surface (source of kinematic dis-turbance) and a work apparatus. For investigations there is used a method of structural mathematical modeling within the limits of which the mechanical oscillating system is compared with a structural circuit equivalent dynamically a sys-tem of automatic control. There is offered a technology of starting simulators transformation ensuring a defini-tion of tie dynamic reactions in characteristic points of element contact connection of the system at the simul-taneous action of two factors. It is shown that the joint action of two external disturbances does not change frequencies of characteristic oscillations in the system, but affects considerably its dynamic properties. There are shown diagrams of the dependences of motion points and values of tie dynamic reactions in characteristic points upon a frequency of external im-pact. The manifestations of new dynamic effects in the interactions of system elements between each other as a formation of additional modes of oscillation dynamic damping and amplitude-frequency characteristics (AFC) of a certain type are shown. Dynamic effects predetermine potentialities of a purposeful tuning of vibration fields. It is shown that the value of the shown DMC mass of affect substantially dynamic properties of the system that can be used both for motion parame-ter control, and for the assessment of tie dynamic reac-tions arising at that in the system.


Author(s):  
А. V. Eliseev ◽  

The paper is devoted to a new approach to the formation of the methodological basis of system analysis in application to problems of the dynamics of mechanical oscillatory systems taking into account the forces of viscous friction. A mechanical oscillatory system with two mass-inertia elements connected to the support surfaces and to each other by elastic-dissipative elements is considered. A method for estimating the free movements of a mechanical oscillatory system is developed based on the characteristics expressed in terms of the parameters of the lever connections between the partial blocks in the form of a gear ratio. Mathematical models are built on the basis of Lagrange formalism, algebraic methods, and the theory of functions of a complex variable. A matrix method is proposed for constructing frequency functions and damping functions for mechanical oscillatory systems with two degrees of freedom based on the ratio of the potential and kinetic energy of the system, taking into account the forces of viscous friction. For a mechanical system in which the connection of elements with a single reference surface is reset, a graphic analytic analysis of the extreme properties of the corresponding frequency functions and damping functions is performed. A topological approach is proposed.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 444
Author(s):  
Guoning Si ◽  
Liangying Sun ◽  
Zhuo Zhang ◽  
Xuping Zhang

This paper presents the design, fabrication, and testing of a novel three-dimensional (3D) three-fingered electrothermal microgripper with multiple degrees of freedom (multi DOFs). Each finger of the microgripper is composed of a V-shaped electrothermal actuator providing one DOF, and a 3D U-shaped electrothermal actuator offering two DOFs in the plane perpendicular to the movement of the V-shaped actuator. As a result, each finger possesses 3D mobilities with three DOFs. Each beam of the actuators is heated externally with the polyimide film. The durability of the polyimide film is tested under different voltages. The static and dynamic properties of the finger are also tested. Experiments show that not only can the microgripper pick and place microobjects, such as micro balls and even highly deformable zebrafish embryos, but can also rotate them in 3D space.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2562
Author(s):  
Tomasz Dzitkowski ◽  
Andrzej Dymarek ◽  
Jerzy Margielewicz ◽  
Damian Gąska ◽  
Lukasz Orzech ◽  
...  

A method for selecting dynamic parameters and structures of drive systems using the synthesis algorithm is presented. The dynamic parameters of the system with six degrees of freedom, consisting of a power component (motor) and a two-speed gearbox, were determined, based on a formalized methodology. The required gearbox is to work in specific resonance zones, i.e., meet the required dynamic properties such as the required resonance frequencies. In the result of the tests, a series of parameters of the drive system, defining the required dynamic properties such as the resonance and anti-resonance frequencies were recorded. Mass moments of inertia of the wheels and elastic components, contained in the required structure of the driving system, were determined for the selected parameters obtained during the synthesis.


Author(s):  
I.P. POPOV

A mechanical oscillatory system with homogeneous elements, namely, with n massive loads (multi– inert oscillator), is considered. The possibility of the appearance of free harmonic oscillations of loads in such a system is shown. Unlike the classical spring pendulum, the oscillations of which are due to the mutual conversion of the kinetic energy of the load into the potential energy of the spring, in a multi–inert oscillator, the oscillations are due to the mutual conversion of only the kinetic energies of the goods. In this case, the acceleration of some loads occurs due to the braking of others. A feature of the multi–inert oscillator is that its free oscillation frequency is not fixed and is determined mainly by the initial conditions. This feature can be very useful for technical applications, for example, for self–neutralization of mechanical reactive (inertial) power in oscillatory systems.


2004 ◽  
Vol 127 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Yongjun Lai ◽  
Marek Kujath ◽  
Ted Hubbard

A micro-machined manipulator with three kinematic degrees-of-freedom (DOF): x, y, and φ is presented. The manipulator is driven by three thermal actuators. A six DOF discrete spring-mass model of the compliant mechanism is developed which manifests the dynamic properties of the device. Numerical simulations are compared with experimental results.


2012 ◽  
Vol 629 ◽  
pp. 171-175
Author(s):  
Wen Zhong Jin ◽  
Su Fang Li ◽  
Wei Zhang

The new technology of superalloy vacuum-electromagnetic casting was developed and the feeding mathematical model melt in vacuum-electromagnetic casting was established. The availability of mathematical model was approved by the experiments of the IN100 superalloy. The experimental results indicate that the feeding capacity of melt in vacuum casting can be greatly increased by imposing the 50Hz, 60A rotating electromagnetic stirring, which can decrease the central shrinkage cavity in superalloy ingots, so the quality of the superalloy ingots can be wide-range improved.


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