Crank Mechanism Research Articles

JUSTIFICATION OF PARAMETERS AND DEVELOPMENT OF A LINEAR ASYNCHRONOUS ELECTRIC DRIVE OF A VIBROCENTER GRAIN SEPARATOR

The development of agriculture depends on the conditions of quality assurance and preservation of grown and produced products. To solve these problems, in particular, grain processing enterprises must have a well-equipped technical base capable of ensuring high-quality separation of grain, which arrives without losses in the short term. Separation of cereals is a key place not only in the processing process, but also is one of the main ways to increase the yield of cereals, as the separation process contributes to the selection of the highest quality (physiologically mature) seed. Work with grain is based on basic principles, which include advanced technology, flow processing methods and automation of the production process. Post-harvest processing of grain must ensure the timely organization and timely execution of all its stages while ensuring the minimum possible values ​​of energy and complexity of the process. The vast majority of separation machines used today in agriculture have a fairly low productivity, as most of them use gravitational forces to clean grain mixtures. Every year, production requirements are growing, and require new, most energy and technologically efficient methods of separation, as well as the creation or modernization of existing separating machines with higher productivity, quality and efficiency of separation of grain mixtures. Without theoretical and practical research, grain cleaning machines are impossible to further improve and create new, high-tech and energy-efficient structures. The main difficulty in considering improvements in temporary grain vibratory centrifugal separators is the lack of a basic design scheme of the vibrating drive, which will allow the implementation of a given law of oscillations with the required accuracy and ability to smoothly adjust the amplitude and frequency of oscillations in the vertical plane. Interesting and broad prospects for the development of electric drive are associated with the use of so-called linear motors. A large number of production mechanisms and devices have translational or reciprocating motion of the working bodies (lifting and transport machines, feed mechanisms of various machines, presses, hammers, etc.). As the drive of these mechanisms and devices, conventional electric motors were used in combination with special types of mechanical transmissions (crank mechanism, screw-nut transmission), transformed the rotational motion of the working body. Linear motors can be asynchronous, synchronous and direct current, repeating the principle of their operation of the corresponding motors of rotational motion.

Modelling and simulation of virtual NOx sensor for diesel engine using thermodynamic model

This paper presents a thermodynamic model for virtual NOx sensor which is capable of predicting nitrogen oxides (NOx) emissions in diesel engines. In-cylinder volume and pressure are the inputs from estimator. The proposed method is based on a two-zone thermodynamic model which divides the combustion chamber into burned and unburned gas zone. The contribution of proposed method arises from: In-cylinder volume and pressure are the inputs from estimator using slider crank mechanism. And the two-zone thermodynamic modeling framework is applied in a way that the thermodynamic equations can be solved in a closed form, which provides the basis for achieving high level of predictiveness using MATLAB which uses ADVISOR as prerequisite for the project. The model is validated using real data values. The model is suitable for two different direct injection diesel engines, i.e. a light and a heavy-duty engine. Also, it maintains a low pipe emission which minimizes fuel consumption.

A Crank Mechanism with Elastic Joints Having Preset Characteristics

A Crank Mechanism with Elastic Joints Having Preset Characteristics

Analysis of the combination of the slider-crank and cam mechanism to drive the automatic bandsaw blade grinder

A slide crank and cam mechanism can be combined and used to drive a bandsaw blade grinder. The movement of these mechanisms must ensure a harmonious combination to avoid the impacts of a collision and dynamic load that appears on the cam and roller surfaces. The technical parameters can be determined by methods of geometry, or 3D simulation, or analytical methods. In order to flexibly design the cam and slide crank mechanism, this study uses the analytic method. By setting up mathematical formulas and applying Mathcad software, it allows to quickly determine and change the initial parameters of the mechanisms, evaluates their changes to the stroke and structural profile. Simultaneously, the graphs of the stroke, velocity, and acceleration of the cam mechanism allow the designer to evaluate and select suitable parameters.

Identification and Machine Learning Prediction of Nonlinear Behavior in a Robotic Arm System

In this study, the subject of investigation was the dynamic double pendulum crank mechanism used in a robotic arm. The arm is driven by a DC motor though the crank system and connected to a fixed side with a mount that includes a single spring and damping. Robotic arms are now widely used in industry, and the requirements for accuracy are stringent. There are many factors that can cause the induction of nonlinear or asymmetric behavior and even excite chaotic motion. In this study, bifurcation diagrams were used to analyze the dynamic response, including stable symmetric orbits and periodic and chaotic motions of the system under different damping and stiffness parameters. Behavior under different parameters was analyzed and verified by phase portraits, the maximum Lyapunov exponent, and Poincaré mapping. Firstly, to distinguish instability in the system, phase portraits and Poincaré maps were used for the identification of individual images, and the maximum Lyapunov exponents were used for prediction. GoogLeNet and ResNet-50 were used for image identification, and the results were compared using a convolutional neural network (CNN). This widens the convolutional layer and expands pooling to reduce network training time and thickening of the image; this deepens the network and strengthens performance. Secondly, the maximum Lyapunov exponent was used as the key index for the indication of chaos. Gaussian process regression (GPR) and the back propagation neural network (BPNN) were used with different amounts of data to quickly predict the maximum Lyapunov exponent under different parameters. The main finding of this study was that chaotic behavior occurs in the robotic arm system and can be more efficiently identified by ResNet-50 than by GoogLeNet; this was especially true for Poincaré map diagnosis. The results of GPR and BPNN model training on the three types of data show that GPR had a smaller error value, and the GPR-21 × 21 model was similar to the BPNN-51 × 51 model in terms of error and determination coefficient, showing that GPR prediction was better than that of BPNN. The results of this study allow the formation of a highly accurate prediction and identification model system for nonlinear and chaotic motion in robotic arms.

ANALYSIS OF RIGID AND FLEXIBLE DYNAMICS OF A SPACE-SLIDER-CRANK MECHANISM BASED ON FINITE ELEMENT METHOD

The investigation analyzes effects of clearance size in revolute and spherical joints with clearance on rigid-flexible dynamic of a space slider crank mechanism by finite element method. The model of the mechanism was designed by Solidworks and then velocity, acceleration, displacement, stress and contact force were determined by finite element analysis of rigid-transient dynamic in ANSYS. The results simulation indicated that the clearance size in revolute and spherical with clearance has sightly effected on the velocity of the slider, but has significantly effected on acceleration, contact force as journal and ball impact into bearing and socket with high peaks of acceleration and contact force as presented in the graph of acceleration and contact forces. The graph outlined that journal and ball motion with three types: free light, contact and impact motion. Clearance size created deviation for the displacement of the slider from 4.29 mm to 9.87 mm and maximum principal stress increases from 8.4 MPa to 10 MPa when clearance size increases from 0 mm to 0.3 mm.

Integrated Planting Machine with Metering Mechanism Suitable for Various Seeds

This study was conducted for the purpose of developing and manufacturing integrated planting machine with a disc metering device attached crank mechanism suitable for many seeds of different shapes and size. A (4.5 Hp) diesel engine as a source of power for machine ground wheel rotation and metering system parts motivation, machine was tested under three ground wheel revolutions GR (30, 45 and 55) rpm, three metering disc to ground wheel revolution ratios MG (0.25, 0.3 and 0.5) and three kinds of seeds variety SV (sun-flower seed, cowpea and black seed) .Experimental measurements were taken for the purpose of characterizing the experimental seed factors as follows:shape index (SI), weight of 1000 seeds (W), seeds moisture content (MC) determination, Actual seeds volume (V) and real density (γ). To evaluate the influence of previous factors there were procedural experiments on machine performance with main three measurements visible, invisible and total seeds damage (SD), actual seed feeding rate (SF) /10m of planting row distance and seeds lateral scattering frequency (L.S %) around the planting row centerline. The results showed that: experimental seeds tend to be oval in shape factor and have a low moisture content less than 18.5%, the highest (SD) at the higher value of ground wheel revolutions GR3=55 rpm. The best feeding rate for black seed (4 to 5 seed in feed-blot) obtained with MG2=0.3 while sun flower seed and cowpea (1 seed in feed-blot) with planting distance 20 cm at MG1=0.25 and GR1= 30 rpm.

Development and research of the press operating mechanism, made in the form of the wedge-joint mechanism with a curving wedge for separation operations

The applicability of a wedge-joint mechanism with a curving wedge in presses for the implementation of metal forming separation processes was substantiated. The paper states the fact that the wedge-joint mechanism graph of the deformation force change is the closest to the technological typical graph of the force change during separation. At the same time, the wedge-joint mechanism with a curving wedge has a lower height of the parts in comparison with the traditional crank mechanisms, which provides less elastic deformation and press dynamics. The use of the additional wedge mechanism in a press with the wedge-joint mechanism with a curving wedge to ensure the approximation motion is proved. This makes it possible to reduce the energy consumption for elastic deformation and further reduce the dynamic force. The mathematical models of the wedge-joint mechanism with a curving wedge, presented in the form of a two-slide link mechanism, were developed, allowing to perform its structural, kinematic, and dynamic analysis. Based on the analysis of the proposed mathematical models, dependencies were identified and a procedure for calculating the geometric, kinematic, and power parameters of wedge-joint mechanisms with a curving wedge for separation processes was developed. Comparison of the kinematic and dynamic analyses results carried out by analytical and graphic-analytical methods confirms the reliability of estimates, since their discrepancy is not more than 2.5%. Experimental studies have confirmed the adequacy of mathematical models. The error between the calculated and measured values of the forces on the slide does not exceed 10%.

Innovative solutions to increase productivity, safety and reliability of agricultural products processing equipment

It is noted that the agro-industrial complex is a stable supplier of food for the population and raw materials for various types of economic activities. In addition, works related to sawing of various solid materials (wood, plastic masses, frozen meat and fish products, bones and others are characteristic. The equipment used in this case is characterized by metal capacity, insufficient productivity and low reliability, increased injury hazard. In addition, wood sawing equipment is expensive and high-energy. In connection with the present, based on the study and analysis of the situation, the authors proposed an author's solution that allows reducing the shortcomings of existing equipment by half, providing an increase in productivity, reliability and safety in operation. This is facilitated by innovative design solutions, providing, in particular, sawing of materials when the saw block moves not only downwards, but also upwards according to the principle of a crank mechanism. The following material is devoted to the presentation of the design and principle of the proposed innovative solution.

Solid Edge 3D Model of Synthesized Geared Slider Crank Mechanism with Variable Topology Features

The paper introduces solid edge 3D model of synthesized geared slider crank mechanism. The synthesized mechanism exhibits the features of variable topology mechanism. This mechanism is modeled in solid edge software and presented. The gear connected to the crank provides the possibility of using it as an input and as well as output to the mechanism. The mechanism showcases the single input to multiple output variable topology features.

Kinematic Synthesis of 3R-1P Geared Slider Crank Mechanism with Variable Topology Features for Motion Generation

The paper focuses on synthesis of slider crank mechanism consisting of a single gear as a part of input and output of the mechanism. Complex number method is used as one of the synthesis criteria. This is a planar four link gear slider mechanism having one degree of freedom which is considered for synthesis using variable topology method for the task of motion generation. The mechanism consists of three revolute and one slider joints. Synthesized mechanism exhibits the features of variable topology mechanism in different modes of operation.

The Use of MATLAB in Learning the Velocity Analysis with Relative Velocity Method on Slider Crank Mechanism

In the subject of kinematics, velocity analysis is the fundamental concepts in studying motions in the machines. Graphically velocity analysis, might be difficult to understand by the students, especially if the concepts is explained by conventional teaching method. In this study, development a computer program for velocity analysis of slider crank mechanism is presented. The purpose is to assist the learning process of slider crank kinematics, so the students will easily understand the concept. The computer program is written by using MATLAB. Graphical User Interface is used, so the users are allowed to change the input parameters such as angle of linkage bar, the magnitude and direction of angular velocity etc. Based on the inputs, the computer program displays the outputs such as linear and angular velocity, steps of velocity analysis graphically and its mathematical computations. This computer program has been validated by theoretical calculations. In the future, the application will be developed for other complex mechanism and be implemented in learning of kinematics.

GSM Base Automated CPR Device Using Scotch-Yoke Mechanism

Cardiopulmonary resuscitation (CPR) is another lifesaving technique which will increase the chances of survival after getting cardiac arrest but when done manually it comes with Many problems like knowledge about CPR technique amongst the general population and inability of human to provide CPR as per WHO guideline and as long it needed. The main objective is to make automated CPR device which will provide strokes on chest through motor best scotch yoke mechanism and will give artificial ventilation through resuscitation bag true motor base side crank mechanism with the pulse sensor which will monitor the pulse and give signal to start and stop CPR device. GSM module which will send emergency message to the near hospital after confirming cardiac arrest.

Justification and selection of design parameters of the eccentric gear mechanism of the piston lubrication and filling unit for the mining machines maintenance

Piston pumps are widely used in the lubrication systems of mining machines. When carrying out technical maintenance (MOT), including lubrication and filling works, at the site of operation of mining machines due to the remoteness from repair shops and warehouses of fuels and lubricants (FAL), mobile repair shops (MRS), maintenance units (MU) and mechanized filling units (MFU) are used. The specificity of carrying out maintenance is to create conditions for the supply of oils, working fluids and lubricants to the corresponding systems of mining machines for their refueling. Existing piston pumps and pumping units, as a rule, are single-flow, and the piston is driven by a crank mechanism driven from the engine through a worm gear. The emergence of unique, hydraulic, low-mobility mining machines in open pit mining required a significant increase in the power of the MU and MFU oil pumping units, primarily for greases. However, the traditional design of the drive design of a crank-type piston pump unit at a power of over 80 kW does not allow achieving the specified operating time, it is accompanied by intensive wear of the drive elements and increased dynamics during operation. In addition, it is necessary to apply various designs of pumping units for the supply of liquid and grease lubricants. Thus, it is necessary to develop new circuit solutions for pumping units of the crank type, to improve mobile refueling facilities with a modernized design of the pump unit drive of the mobile lubrication and filling station MRS.

Deep learning of multibody minimal coordinates for state and input estimation with Kalman filtering

In general, multibody models are described with a set of redundant coordinates and additional constraints. Their dynamics is thus expressed through differential algebraic equations. As an alternative, the minimal coordinate formulation permits to describe a rigid system with the minimal number of variables leading to ordinary differential equations which can be employed in a coupled state/input estimation scheme. However, in some cases the explicit relation between the full-system coordinates and the minimal coordinates may not be available or analytically obtainable, as for closed-loop mechanisms. In this work, a previously presented deep learning framework to find the non-linear mapping and reduce a generic multibody model from redundant to minimal coordinates is employed. The resulting equations are then exploited in an extended Kalman filter where the unknown inputs are considered as augmented states and jointly estimated. The necessary derivatives are given and it is shown that acceleration measurements are sufficient for the estimation. The method is experimentally validated on a slider–crank mechanism.

Frequency response of a cantilevered rectangular sheet under harmonic forced excitation in three-dimensional uniform flow

Flexible thin manufactures (sheets) are used in numerous engineering applications. In their manufacturing processes, the sheets are subjected to a fluid flow, and external disturbances can induce vibrations. The vibrations cause severe damage to the sheets. Therefore, an in-depth understanding of the vibration characteristics and excitation mechanism of a sheet in a fluid flow is essential. In this study, the vibration characteristics and excitation mechanism of a sheet under a harmonic forced excitation are investigated by both theoretical calculations and experiments. In the experiments, a harmonic displacement excitation is inputted at the leading edge of a sheet in a wind-tunnel by an exciter using the slider–crank mechanism. In the theoretical analysis, the sheet is modeled as a cantilevered beam, and the fluid force acting on the sheet surface is calculated using three-dimensional theory. The frequency response of the sheet in a uniform flow is investigated with changing the flow velocities and forcing frequencies inputted to the sheet. Finally, the work done by the fluid force acting on the sheet under the harmonic excitation is determined, and the excitation mechanism is discussed.It is found that the flow velocity considerably affects the sheet response. As the flow velocity increases, the amplitude of the second peak of the response becomes larger than that of the first peak. Moreover, the vibration mode of the second peak of the response transforms into a traveling-wave-type mode due to the modal coupling caused by the fluid force.

Development of Multi-Axis Crank Linkage Motion System for Synchronized Flight Simulation with VR Immersion

This paper developed a rotatable multi-axis motion platform combined with virtual reality (VR) immersion for flight simulation purposes. The system could simulate the state of the flight operation. The platform was mainly comprised of three crank linkage mechanisms to replace an expensive six degrees of freedom (DoF) Stewart platform. Then, an independent subsystem which could rotate ±180° was installed at the center of the platform. Therefore, this platform exhibited 4-DoF movement, such as heave, roll, pitch, and yaw. In the servo motor control unit, Visual Studio C# was applied as the software to establish a motion control system to interact with the motion controller and four sets of servo motors. Ethernet Control Automation Technology (EtherCAT) was utilized to communicate the commands and orders between a PC and each servo motor. The optimum controller parameters of this system were obtained using Simulink simulation and verified by experiment. The multiple sets of servo motors and crank linkage mechanisms were synchronized with flight VR imagery. For VR imagery, the software Unity was used to design the flying digital content. The controller was used to transmit the platform’s spatial information to meet the direction of the pilot commands and to compensate the direction of the deviation in spatial coordinates. To achieve synchronized response and motion with respect to the three crank linkage mechanism platform and VR imagery on the tester’s goggle view, the relation of the spatial coordinate of VR imagery and three crank linkage mechanisms was transformed to angular displacement, speed and acceleration which were used to command the motor drive system. As soon as the position of the VR imagery changed, the computer instantly synchronized the VR imagery information to the multi-axis platform and performed multi-axis dynamic motion synchronously according to its commanded information. The testers can thus immerse in the VR image environment by watching the VR content, and obtain a flying experience.

ТЕОРЕТИЧЕСКОЕ ОБОСНОВАНИЕ ОЦЕНКИ ТЕХНИЧЕСКОГО СОСТОЯНИЯ ДВИГАТЕЛЯ ВНУТРЕННЕГО СГОРАНИЯ ПО ВЕЛИЧИНЕ СУММАРНОЙ ЭДС В ПАРАХ ТРЕНИЯ

The research was carried out in order to determine the possibility of assessing the technical condition of an internal combustion engine (ICE) by the value of the total electromotive force (EMF) that occurs in its friction pairs. The contact area of the rubbing parts and the gap between them affects the electrical resistance in contact, and, accordingly, the value of the resulting EMF according to the established dependence. To confirm the theoretical results, studies were carried out on the UMP-417 engine using a developed measuring complex and a manufactured current-collecting device mounted on the output end of the engine crankshaft. With the operating mode corresponding to the speed of the crankshaft 800 min-1, the total value of the EMF in the measurement circuit cylinder liner-engine block-crankshaft-current collector (TSU) was 83...95 mV. At the same time, in the piston–cylinder liner friction pair, it was equal to 37 ... 47 mV, and in the crank mechanism friction pairs - 46...48 mV. The correspondence of the results of the theoretical calculation and bench studies of the values of the EMF value for a real internal combustion engine was: when measured using the Fluke device for the friction unit of the cylinder liner-piston – 62.1 %, for the friction units of the crank mechanism (root neck-connecting rod, connecting rod neck-connecting rod, root neck-engine block) - 15.1 %. When measured by the V1net device, for the cylinder liner – piston friction unit-85.5 %, for the crank mechanism friction units (root neck-connecting rod, connecting rod neck-connecting rod, root necks-engine block) - 93.2 %. The proposed method for determining the state of the engine by the value that occurs in its EMF friction nodes can be used in the technical diagnostics of engines

Simulation and test of a very efficient friction brake actuator with a statically balanced spring mechanism

Current automotive brake systems (pneumatic/hydraulic) are based on a split design: a central unit providing pressure and brake calipers transforming this pressure into clamping forces. Existing electromechanical brake calipers work without a central unit; but despite their simplicity they are not yet used. One major reason is the need of high forces and high electrical power for loading brake pads and calipers during braking. A possible solution is the application of a statically balanced spring mechanism; it stores elastic energy in a preloaded reversible spring mechanism integrated in the caliper. Using a nonlinear linkage mechanism, the stored energy transfers back and forth to and from the elastic parts of the brake caliper. Consequently, the additional power needed for applying and releasing the brake reduces significantly. The article analyzes the basic feasibility of such an actuator based on a double slider crank mechanism, which is determined for an application in a typical automotive disk brake caliper with high clamping forces of 20 kN. Experimental results from a demonstrator under real friction and stiffness conditions are presented and analyzed based on a theoretical model. The results prove the benefits of reducing driving power and also reveal critical points of the design.

Design And Analysis Of Modified Four Stroke Four Revolution Engine

In today’s world, one of the important tasks is to handle the energy available and to minimize the heat losses. In automotive sector, engine is the primary energy source and there are many losses associated with an engine out of which engine cooling and exhaust losses takes major share. In four-stroke SI/CI engines, four strokes of reciprocating cylinder involve two rotations of the crankshaft. These strokes are suction, compression, power and exhaust respectively. A large amount of fuel energy is wasted when fuel is not compressed completely and also at the exhaust of internal combustion engines. This paper focusses on minimizing losses of internal combustion engine by secondary expansion of exhaust gases through 180 ° of crank revolution. For this purpose, four stroke four revolution mechanism is proposed and this is achieved by modifying current slider crank mechanism with double connecting rod arrangement. This modified engine shows an increase in the air standard cycle efficiency by 4.10% where as fuel air cycle efficiency rise is observed to be 5.25%. There is also significant rise observed in the modified engine over conventional engine in terms of gross indicated thermal efficiency and brake thermal efficiency as well.