Розглянуто різні типи механізмів повороту та складання лопатей, які можна використовувати з метою регулювання потужності та стабілізації частоти обертання горизонтально-осьових вітроустановок. Побудовано кінематичні схеми відповідних механізмів. Виведено аналітичні вирази для встановлення залежностей переміщень регулювальних повзунів і відцентрових тягарців від кута повороту лопаті. Наведено рекомендації щодо розрахунку їх кінематичних параметрів (аналогів швидкостей і пришвидшень).

Надано математичну модель динамічних процесів, які виникають у разі фрикційного зміцнення плоских поверхонь деталей машин з використанням інструмента з нарізаними поперечними пазами на його робочій частині.

Проаналізовано основні типи механізмів регулювання потужності горизонтально-осьових вітроустановок малої потужності. З метою підвищення точності регулювання потужності, ефективності та надійності функціонування вітроустановок у широкому діапазоні швидкостей вітру обгрунтовано необхідність подальшого вдосконалення існуючих механізмів регулювання. Розглянуто перспективи створення комбінованих механічних систем, у яких передбачено можливості одночасного повороту та складання лопатей, повороту (або складання) лопатей і виведення вітроколеса з-під вітру.

Розглянуто різні типи комбінованих механізмів одночасного повороту та складання лопатей, які можна використовувати з метою регулювання потужності та стабілізації частоти обертання горизонтально-осьових вітроустановок. Побудовано кінематичні схеми відповідних механізмів. Виведено аналітичні вирази для встановлення залежностей переміщень регулювальних повзунів від кутів повороту та складання лопаті.

The analysis of operation of vibrating conveyers with nonparallel placement of flat springs is carried out. The motion of mechanical oscillating system is investigated. The structure of the supporting unit for flat springs fastening is propounded. This structure allows simplifying of setting-up of two-mass vibrating conveyers with the aim to ensure the effective operation. The models of conveyers with nonparallel placement of springs, providing the accurate calculations of rigidities and angles of flat springs inclinations, considerably simplify the structures of conveyers and their setting-up to ensure the prescribed angles of vibrations. The proposed structure of fastening of flat springs ends allows increasing of operation efficiency of the two-mass vibrating conveyer. Due to such setting-up of the equipment it is possible to compensate some of its theoretical and structural faults. On the basis of presented investigations, it is planned to develop the three-mass models of conveyers-separators with transporting of separated components in different directions.

The analysis of structure diagrams of the two-mass tubular conveyer with two-cycle electromagnetic drive is carried out in the article. Two methods of designing of the elastic system are considered; calculation formulas for elastic system computation are deduced according to different requirements for the operating parameters of conveyers; the comparative analysis of two types of elastic systems is conducted. The recommendations for designing the lengthy tubular vibrating conveyers are presented. According to the considered structural diagrams of the elastic system the models of the lengthy vibrating conveyers with the transporting distances l = 1,5 - 4 m are developed. On the basis of these models the lengthy vibrotransporting systems with the transporting distance l = 5 - 30 m were developed, manufactured and applied in industry. The considered systems ensures the transportation of loose materials (porcelain composition, sand etc.) with maximal speeds up to 800 mm/sec and productivities (for tubes with internal diameter D = 100 mm) up to 30 tons per hour for. It is reasonable to use both considered schemes of elastic systems for development of vibrating tubular conveyers with electromagnetic drive. The conveyers may be designed in two modifications: overhead and supporting. The obtained dependencies allow optimization of the structure and considering the important technical parameters of conveyers (maximal permissible oscillations amplitude, springs stresses, productivity etc.) in the design phase.

The operation of hopper devices, which are used in industry, civil engineering, agriculture and transport, is analyzed on the article. The external factors, which influence the process of charging, storing and discharging of loose cargo (freights) from hopper tanks, are overviewed. The subject of research of presented paper is the improvement of mechanisms of fracturing of products hangs-up (bridges) in hoppers at the stage of designing and setting up of hopper devices. In order to solve the stated problem the schemes of bridges fracturing and the structures of devices for debarment of products bridging and their uniform outflow from the hopper tank are proposed. The proposed schemes are based on the principles used in development of vibratory machinery with mechanical, cam and electromagnetic vibratory principles of structures forming. stiffness of elastic system and of the necessary forces for performing of technological process of bridges fracturing is presented and the recommendations for choosing of the stiffness of the system of elastic elements are suggested. For the hoppers with spring and electromagnetic blocks of bridges fracturing and of metered (batched) feeding of products the structural diagrams of devices are presented and the recommendations for usage of various modifications of devices are suggested. The influence of parameters of flat spring elements on the efficiency of devices operation is overviewed. The structural diagrams of devices with one-cycle and two-cycle electromagnetic vibration exciters and the modifications of elastic systems are considered. the structural diagram of the production prototype of the hopper feeder is presented. The materials of the article, the proposed structural diagrams, the operation scheme of the hopper feeder and the derived analytical formulas may be used by designers, researchers and technologists while improving of existent and developing of new devices.

The problem of substantiation of operational efficiency of vibratory separators designed on the basis of vibratory hopper feeders with electromagnetic vibrations exciters and with conic working bowls is considered in the article. The complex of factors influencing the accuracy and productiveness of separation of coins and disk-shaped products on two or more fractions is overviewed. New models of structures for the effective solution of separation problems are proposed. The design of a highly-efficient and high-performance separator with independent oscillations disturbance is described. The results of experimental investigations of vibratory transportation in elliptical modes of vibrations and of the study of separation efficiency are presented. The recommendations that developers and researchers of such devices may use are given.

The purpose of research. Substantiation of inertial, stiffness and excitation parameters of mechanical oscillatory system of mobile vibratory robot in order to maximize its motion speed. Methodology. The technique of the research is based on fundamental concepts of engineering mechanics and theory of mechanical vibrations. In order to deduce the differential equations of motion of the mechanical system of mobile vibratory robot the Lagrange second order equations were used. The computation modelling of the system's motion caused by periodic excitation forces was carried out using MathCAD software. Results. The design diagram (model) of the two-mass mobile vibratory system with electromagnetic drive was constructed. The mathematical model of its motion was developed and the parameters of the resonance vibro-impact mode of its operation were substantiated. The steady-state and transient conditions of operation of the system under the influence of periodic excitation force of various magnitude were investigated. Scientific novelty. The structure of mobile vibratory device designed on the basis of two-mass oscillatory system with vibro-impact operation mode was substantiated. The differential equations of motion of the proposed system were set up taking into account the nonlinear stiffness characteristic of the elastic element connecting two oscillating bodies. The influence of the system's excitation parameters on its motion speed was analysed. This allows to substantiate the rational magnitude and frequency of the excitation force. Practical value. The results of the carried-out investigations can be used while designing and developing control systems of mobile vibratory transporting and robotic devices in order to ensure the possibility of changing the speed of their motion without changing the inertial and stiffness parameters of their mechanical oscillating systems. Scopes of further investigations. While carrying out further investigations it is necessary to study the possibility of changing the nonlinearity of stiffness characteristic of the elastic element in order to change the kinematic parameters of the system's motion. In addition, it is necessary to substantiate the mechanisms of changing the direction of motion of mobile vibratory robot.

Problem statement. Designing and manufacturing of efficient resonant vibratory lapping machines with linear oscillations of laps demand an accurate and detailed calculation of parameters of their elastic systems and electromagnetic drives. Purpose. The main objective of this research consists in derivation of analytical dependencies for calculating the stiffness and excitation parameters of mechanical oscillatory system of vibratory finishing machine in order to ensure its resonance operation mode. Methodology. The technique of the research is based on fundamental concepts of engineering mechanics, strength of materials and theory of mechanical vibrations. Findings (results). The design diagram of mechanical oscillatory system of vibratory finishing machine with linear oscillations of laps is considered and corresponding equations of motion are presented. Analytical dependencies for calculating stiffness and excitation parameters of the system are deduced. The example of parameters calculation is given and time dependencies of the system's motion are constructed. Originality (novelty). The mathematical model of linear oscillations of the three-mass mechanical system of vibratory finishing machine was developed. The possibilities of performing the laps dressing using "lap over lap" method were substantiated. Practical value. The results of the performed investigations can be used during designing new designs and improving existing structures of vibratory finishing machines for lapping flat surfaces of cylindric and prismatic parts. Scopes of further investigations. In further investigations, it is necessary to analyse the influence of the viscous damping on the system's motion. In order to substantiate (justify) the obtained theoretical results, the experimental investigations should be carried out.

The calculation diagrams of oscillating systems and operation features of vibratory finishing machines are considered. The mathematical models of three-mass and four-mass oscillating systems are presented. The amplitude values of the oscillating masses displacements are derived. The functions of inertial and stiffness parameters optimization are formed. The optimization problems are solved with a help of MathCAD software. On the basis of synthesized inertial and stiffness parameters, the amplitude-frequency characteristics of the oscillating systems of vibratory finishing machines are formed and analyzed. In order to verify the validity of the proposed theoretical approaches, the simulation of the mathematical model of the oscillating system motion is carried out by means of numerical solving of the system of differential equations of the oscillating masses motion. The proposed structural diagrams and the operation schemes of the vibratory finishing machine, as well as the derived analytical formulas may be used by designers, researchers and technologists while improving existent and developing new equipment for vibro-finishing treatment.

Problem statement. The use of existing and the most widespread drives (wheeled and caterpillar one) is sometimes limited by complicated operational conditions while moving on rough terrain. The mentioned drives require relatively flat surface to be operated effectively. A rocky or a hilly terrain imposes the demand of the use of alternative types of drives, in particular, walking ones. Purpose. In this paper, there will be proposed and analysed one of the possible structures of the walking mechanism for mobile robotic system to be used on rough terrain. Methodology. While carrying out the investigations, the structural and kinematic synthesis of the eight-bar hinge-lever walking mechanism has been performed using the well-known methods of the Theory of Machines and Mechanisms, in particular, the method of closed vector loops. In order to conduct experimental investigations and simulation of the mechanism motion, the applied software SolidWorks and MapleSim has been used. Findings (results). The structure and geometrical parameters of the eight-bar walking mechanism have been synthesized with the aim to ensure the required trajectory and kinematic characteristics of the supporting foot motion. Originality (novelty). The analytical dependencies describing the trajectory of each hinge of the analysed walking mechanism have been derived and the kinematic optimization synthesis problem has been solved. This allowed to substantiate of the mechanism's geometrical parameters and to analyse its kinematic characteristics. Practical value. The proposed structure of the walking mechanism can be effectively used in various mobile robotic systems and in transporting and technological machines in order to ensure the possibility of their use on rough terrain where there is no ability to use wheeled and caterpillar drives. Scopes of further investigations. While carrying out further research, it is necessary to analyse the influence of the weight coefficients on the solution of the optimization problem, as well as to take into account the necessity of changing the step length and the foot lifting height during the process of walking according to the surface obstacles sizes.

The purpose of research. Analysis of influence of stiffness parameters of mobile vibratory device with two unbalanced vibration exciters on eigenfrequencies of its mechanical system and substantiation of stiffness parameters in order to ensure its energy-efficient resonance operation mode. Methodology. The technique of the research is based on fundamental concepts of engineering mechanics and theory of mechanical vibrations. In order to deduce the differential equations of motion of the mechanical system of mobile vibratory robot the d'Alambert - Lagrange principle was used. The computation modelling of the system's motion caused by periodic excitation forces was carried out using MathCAD software. Results. The design diagram (model) of the two-mass mobile vibratory system with two unbalanced vibration exciters was constructed. The mathematical model of its motion was developed and the parameters of the resonance mode of its operation were substantiated. In particular, the influence of stiffness parameters of mobile vibratory device with two unbalanced vibration exciters on eigenfrequencies of its mechanical system was analysed. The steady-state and transient conditions of operation of the system under the influence of periodic excitation force were investigated. Scientific novelty. The analytical dependencies for determination of stiffness parameters of the mechanical oscillating system of two-mass mobile vibratory device with two unbalanced vibration exciters were derived in order to ensure its operation in energy-efficient resonance mode. The value of the phase shift of the unbalanced exciters' rotation was substantiated in order to maximize the device's motion speed. Practical value. The results of the carried out investigations can be used while designing and developing control systems of mobile vibratory transporting and robotic devices in order to ensure the possibility of changing the speed of their motion without changing the frequency and direction of rotation of unbalanced vibration exciters.

The purpose of the paper. Substantiation of structure (design), parameters and operation modes of the improved vibratory finishing machine. Analysis of dynamical processes which occur during "lap over lap" dressing. Investigation methodology. Mathematical model of motion of the mechanical system of vibratory finishing machine was developed on the basis of Lagrange differential equations of the second order. For the purpose of describing friction between the working surfaces of the laps, the Coulomb friction model was used. Stiffness parameters of all elastic elements were modeled in accordance with the Hooke's law. Energy losses in elastic elements during their tension-compression were taken into account by corresponding coefficients of dissipation (damping). Simulation modelling of motion of the machine's mechanical oscillatory system was carried out in MathCAD software by means of solving the derived differential equations of the system's motion using the numerical methods of Runge - Kutta. Obtained results. Structural and functional peculiarities of the improved vibratory finishing machine for lapping flat surfaces of cylindric and prismatic parts were considered. Design (calculation) diagram of its mechanical oscillatory system was substantiated and differential equations of motion of oscillating masses were derived. Simulation modelling of the laps' motion during their dressing was carried out and the correspondence of the obtained results to the input modelling parameters (operation in near-resonance mode with the given oscillation amplitudes) was analyzed. Scientific novelty. For the first time we obtained following results: spatial design (calculation) diagram of mechanical oscillatory system of the improved vibratory finishing machine was proposed; mathematical model of plane-parallel motion of oscillating masses (with circular trajectories of oscillations) was developed; possibilities of performing the laps dressing using "lap over lap" method were substantiated by means of ensuring their circular oscillations. Practical value. The results of the performed investigations can be used during designing new and improving existing structures of vibratory finishing machines for finishing treatment (lapping) of flat surfaces of cylindric and prismatic parts.

Індекс рубрикатора НБУВ: З252.8

Рубрики:

Сонячні батареї

Шифр НБУВ: Ж44086 Пошук видання у каталогах НБУВ 

Problem statement. Mobile robots have awoken a large interest between scientists and designers in the last few years. One of the prospective drives of such robots is based on pneumatically operated system with no use of electric, heat, magnetic or other types of energy. Purpose. The main purpose of this research consists in substantiation of structure and parameters of pneumatic system of mobile robot with orthogonal walking drive. Methodology. The research is carried out using the basic laws and principles of mechanics, pneumatics and automation. The numerical experiment is conducted in MathCAD software and computer simulation of the robot's motion is performed using SolidWorks software. Findings (results) and originality (novelty). The improved structure of the mobile robot with orthogonal walking drive is proposed. The pneumatically operated system ensuring the robot's motion is substantiated. Practical value. The proposed design of walking robot can be used while designing industrial (production) prototypes of mobile robotic systems for performing various activities in the environments that are not suitable for using electric power. Scopes of further investigations. While carrying out further investigations, it is necessary to ensure the possibility of changing motion direction of mobile robot by means of pneumatic drive. In addition, it is expedient to design the devices for changing motion speed of the robot and the height of lifting of its feet.

Проаналізовано конструктивні та функціональні особливості тримасового вібротранспортера (ВТ) із напрямленими коливаннями та розглянуто можливі сфери його використання. Проаналізовано основні навантаження на елементи механічної коливальної системи (МКС) ВТ і на базі диференціальних рівнянь Лагранжа II роду розроблено її математичну модель, яка описує рух системи за прикладання синусоїдальної збурювальної сили між проміжною та реактивною масами системи. Використовуючи загальні методи розв'язування систем лінійних неоднорідних диференціальних рівнянь зі сталими коефіцієнтами, отримано вирази для знаходження амплітуд коливань усіх мас системи за усталених режимів роботи. Наведено алгоритм розрахунку інерційно-жорсткісних параметрів МКС ВТ із напрямленими коливаннями. Відповідно до заданих мас робочого органу та рами транспортера визначено жорсткості відповідних пружних елементів і віброізоляторів, величину реактивної (збурювальної) маси та підібрано характеристики електромагнітного віброзбуджувача. На базі виведених залежностей амплітуд коливань робочих мас в усталених режимах роботи та з урахуванням розрахованих інерційних, жорсткісних і силових параметрів коливної системи ВТ побудовано відповідні амплітудно-частотні характеристики та часові залежності переміщень коливальних мас. Встановлено, що номінальна амплітуда коливань робочих тіл ВТ в усталеному режимі роботи досягає 3 мм. За розрахованими параметрами коливної системи та параметрами збурення за допомогою побудованої математичної моделі тримасової коливної системи ВТ змодельовано її рух. За результатами імітаційного моделювання зроблено висновки про збіжність результатів аналітичних досліджень і віртуального експерименту. Обгрунтовано наявність синфазного руху проміжної та реактивної мас, зумовленого реалізацією ефекту "нульової жорсткості" з метою забезпечення високоефективного резонансного режиму роботи. З метою оцінювання адекватності запропонованої математичної моделі механічної системи ВТ проаналізовано вплив частоти та амплітуди збурювального зусилля на характеристики руху коливних мас. Зокрема, проаналізовано випадки збільшення та зменшення збурювальної частоти вдвічі та збільшення амплітуди в 1,5 разу та її зменшення вдвічі. Обгрунтовано, що зміна амплітуди збурювального зусилля зумовлює пропорційну зміну амплітуди відхилень робочих мас від їх положень рівноваги, тоді як зміна частоти збурення зумовлює суттєве зменшення амплітуди коливань проміжної та активної мас, оскільки має місце "зсув" системи від резонансного режиму роботи.

The tutorial covers the main issues of three-dimensional design of spatial objects. Considerable attention is paid lo the concept uf using 3D modelling in modern SAD systems, ihe principles of modern 3D modelling in industrial design, features of its implementation in educational process. The modern technologies of 3D scanning and 3D priming are described. Practical 3D-modelling exercises in SolidWorks CAD system are presented.

Problems and prospects of using the walking mode for producing motion of robotic systems are considered. Advantages and spheres of the use of mobile robotic systems equipped with walking movers are substantiated. Preferences of cyclic (lever) walking mechanisms are analyzed. The kinematic parameters of four-bar crank-rocker walking mechanism, constructed on the basis of Chebyshov - Umnov mechanism, are accepted as the subject of research. The process of motion of the supporting foot of the walking mechanism is accepted as the object of research. The main aim of the investigation consists in carrying out structure and kinematics analysis of the mentioned mechanism with further derivation of analytical dependencies for calculating kinematic parameters of the supporting foot motion. The special features of the structure of four-bar walking mechanism and theoretical foot loci (paths) are considered. The form of the most reasonable path for further research is established. As a result of carried out structure analysis, it is ascertained that the mechanism consists of two structural groups: that of the first class and that of the second class second order first type. As a result of kinematics analysis, the analytical expressions for calculation of coordinates of the supporting foot hinge of the walking mechanism depending on geometric parameters of the mechanism and the angle of the crank rotation are deduced. The prospects of further investigation under the themes of the paper are analyzed. In particular, the goal function, which may be used for further optimization of structural parameters of the mechanism, is considered and the use of applied software for solving optimization problem is suggested. The optimization problem consists in evaluating such geometric parameters of the walking mechanism which allow the motion of the supporting foot in accordance with the prescribed (specified) path.

Індекс рубрикатора НБУВ: З252.8

Рубрики:

Сонячні батареї

Шифр НБУВ: Ж44086 Пошук видання у каталогах НБУВ