Shaft Rotational Speed Research Articles

SYNCHRONOUS ELECTRIC MOTOR WITH HIGHER SPEED ROTATION AND BALANCED ROTOR

Increasing the speed of rotation of electric motors is an urgent task for turbine mechanisms – pumps, fans, compressors. Traditional synchronous motors have a rotation speed that is less than or equal to the frequency of the supply voltage. The article proposes a design and considers the principle of operation of a synchronous electric motor with double rotation speed. It has three reluctance rotors with one pole, for static and dynamic balancing, and the stator winding is supplied with voltages out of phase by π/6. The proposed design of a synchronous motor with eighteen phases of the stator winding and, with three rotors, the axes of which are offset relative to the axis of rotation of the output shaft. The use of such a design makes it possible to double the rotation speed of the output shaft in comparison with the frequency of the supply voltages. A description of the principle of operation of the motor and its mathematical description are given, taking into account the structural features of the stator-rotor magnetic circuit. The main advantage of the proposed engine in comparison with a high-speed engine is static and dynamic balancing.

Distribution-Independent Empirical Modeling of Particle Size Distributions—Coarse-Shredding of Mixed Commercial Waste

Particle size distributions (PSDs) belong to the most critical properties of particulate materials. They influence process behavior and product qualities. Standard methods for describing them are either too detailed for straightforward interpretation (i.e., lists of individual particles), hide too much information (summary values), or are distribution-dependent, limiting their applicability to distributions produced by a small number of processes. In this work the distribution-independent approach of modeling isometric log-ratio-transformed shares of an arbitrary number of discrete particle size classes is presented. It allows using standard empirical modeling techniques, and the mathematically proper calculation of confidence and prediction regions. The method is demonstrated on coarse-shredding of mixed commercial waste from Styria in Austria, resulting in a significant model for the influence of shredding parameters on produced particle sizes (with classes: >80 mm, 30–80 mm, 0–30 mm). It identifies the cutting tool geometry as significant, with a p-value < 10−5, while evaluating the gap width and shaft rotation speed as non-significant. In conclusion, the results question typically chosen operation parameters in practice, and the applied method has proven to be valuable addition to the mathematical toolbox of process engineers.

Modeling the dependence of the foam concrete structural quality coefficient on the speed and duration of mixing the foam concrete mixture

Experimental studies of the technological factors’ influence on the physical and mechanical properties of foam concrete were carried out. Additive Portland cement was used as a binder. Finely ground quartz sand of fractions 0.08-0.16 and 0.16-0.315 mm was used as a filler. Protein foaming agent Arecom-4 was used as a foaming agent. The porization time of the aerated concrete mixture was controlled using a stopwatch, and the rotation speed of the vertical rotor mixer shaft was controlled with a digital photo-tachometer. In the experiments, the following factors were varied: mixture porization time, mixing speed. The main characteristics of foam concrete were determined by testing the prototypes or their fragments according to the methods of the relevant regulatory documents using verified equipment. In the research laboratory of the DSTU, the studies on the influence of the speed and duration of mixing the foam concrete mixture on the density, strength and coefficient of the resulting foam concrete structural quality were carried out. The article presents the experimental dependences of the investigated characteristics on the speed and time of mixing the foam concrete mixture. The parameters of density and strength show a monotonic decline during pore formation, while the structural quality coefficient exhibits its maximum. The behavior of density, strength, coefficient of structural quality can be described in a single model using the parameters that reflect bonds loosening, a general decrease in the number of bonds in the material and the bonds’ change spatial distribution.

Investigation of the Tribological Performance of Heterogeneous Slip/No-Slip Journal Bearing Considering Thermo-Hydrodynamic Effects

The slip boundary has an important influence on hydrodynamic journal bearing. However, less attention has been paid to the positive effect of slip on thermal behaviour. In this study, a computational fluid dynamics (CFD) analysis investigating the thermo-hydrodynamic (THD) characteristics of heterogeneous slip/no-slip bearings running under steady, incompressible, and turbulent conditions is presented. A comprehensive analysis is made to investigate the THD behaviours of heterogeneous slip/no-slip bearings in terms of lubricant pressure, temperature distribution, volume fraction of vapor, and load-carrying capacity when they are running under different shaft rotational speeds. The multiphase cavitation model is adopted to represent the real operational condition of the journal bearing. Numerical results show that the load-carrying capacity of the heterogeneous slip/no-slip bearing can be significantly increased by up to 100% depending on the rotational speed. It is also observed that there is an optimal journal rotational speed for maximizing the load-carrying capacity. An insightful new finding is revealed in a numerical framework, wherein it is found that by introducing the heterogeneous slip/no-slip pattern, the maximum temperature can be reduced by up to 25% in comparison with a conventional bearing.

Robust adaptive observer-based finite control set model predictive current control for sensorless speed control of surface permanent magnet synchronous motor

The objective of the paper is to present the efficient and dynamic sensorless speed control of a surface permanent magnet synchronous motor (SPMSM) drive at a wide speed range. For high-performance speed sensorless control, a finite control set model predictive current control (FCS-MPCC) algorithm based on a model reference adaptive system (MRAS) is proposed. With the FCS-MPCC algorithm, the inner current control loop is eliminated, and the limitations of the cascaded linear controller are overcome. The proposed speed sensorless control algorithm provides an efficient speed control technique for the SPMSM drive owing to its fast dynamic response and simple principle. The adaptive mechanism is adopted to estimate the rotor shaft speed and position used in FCS-MPCC for dynamic sensorless control. FCS-MPCC uses a square cost function to determine the optimal output voltage vector (VV) from the switching states that give the low cost index. A discrete-time model of a system is used to predict future currents across all the feasible VVs produced by the voltage source inverter. The VV that reduced the cost function is adopted and utilized. Simulation results showed the efficacy of the presented scheme and the viability of the proposed sensorless speed control design under various load conditions at a wide speed operation range.

Design Optimization and Experiment of Four-Row Potato Seedling-Cutting Machine

HighlightsBased on the innovative analysis of the seedling-cutting operation mechanism, five shapes of seedling-cutting blades were designed, and a four-row potato seedling-cutting machine was developed.The kinematics and mechanics of seedling-cutting blades were analyzed, which can provide a theoretical basis for the selection of experimental factors.A regression orthogonal experiment and variance analysis were carried out to verify the performance of the four-row potato seedling-cutting machine. Finally, the main and secondary factors affecting the seedling-cutting performance and the optimal parameter combination were obtained.Compared with other studies, the structure of the seedling-cutting blades are more complete in this study. The test results show that the qualified rate of the broken length of the potato seedlings is significantly improved, the missed cutting rate of the potato seedlings is reduced, and the length of the stubble is more uniform, which greatly improves the quality of seedling-cutting.Abstract. A four-row potato seedling-cutting machine was designed to address the problems associated with potato seedling-cutting machines with low qualified rates of broken length and stubble length and high missed cutting rates. Based on the analysis of the seedling-cutting operation mechanism, key components were designed, and the kinematics and mechanics were analyzed. A regression orthogonal experiment was carried out, taking the rotation speed of the seedling-cutting blade shaft, forward speed of the seedling-cutting machine, and height of the short blade of the ridge top from the ridge platform as the experimental factors and the qualified rate of the broken length of the potato seedlings, missed cutting rate of the potato seedlings, rate of carrying potatoes, and length of the stubble as experimental indexes. The results showed that the prioritized impact of various factors on the qualified rate of the broken length of the potato seedlings ranked as follows: the rotation speed of the seedling-cutting blade shaft > the height of the short blade of the ridge top from the ridge platform > the forward speed of the seedling-cutting machine. The prioritized impact of various factors on the missed cutting rate of the potato seedlings ranked as follows: the forward speed of the seedling-cutting machine > the rotation speed of the seedling-cutting blade shaft > the height of the short blade of the ridge top from the ridge platform. The prioritized impact of various factors on the rate of carrying potatoes and the length of the stubble ranked as follows: the height of the short blade of the ridge top from the ridge platform > the rotation speed of the seedling-cutting blade shaft > the forward speed of the seedling-cutting machine. The optimal parameter combination was a rotation speed of the seedling-cutting blade shaft of 1400 r/min, forward speed of the seedling-cutting machine of 4.22 km/h, height of the short blade of the ridge top from the ridge platform of 62 mm. Based on this combination, the qualified rate of the broken length of potato seedlings was 94.1%, the missed cutting rate of the potato seedlings was 0.30%, the rate of carrying potatoes was 0.49%, and the length of the stubble was 54 mm. The index values of the verification experiments were 94.6%, 0.38%, 0.53%, and 56 mm, which were better than the standard values, indicating that this machine meets the basic operation requirements. The test results can provide theoretical support and technical reference for improving the parameter and structural design of a potato seedling-cutting machine. Keywords: Field experiment, Flail blade, Potato, Seedling-cutting machine.

Mathematical modeling of centrifugal machines rotors seals for the purpose of assessing their influence on dynamic characteristics

With an increase of equipment parameters, such as the pressure of the sealing medium and the speed of shaft rotation, the problems ensuring its hermetization efficiency are rising up. In addition to hermetization itself, the sealing system affect the overall operational safety of the equipment, especially vibratory. Groove seals are considered as hydrostatodynamic supports capable of effectively damping rotor oscillations. To determine the dynamic characteristics, models of grooved seals and single-disc rotors with grooved seals are examined. The obtained analytical dependences for computation of dynamic characteristics for the hydromechanical rotor-seals system, describing radial-angular oscillations of the centrifugal machine rotor in groove seals are presented as well as the formulas for computation of amplitude frequency characteristics. An example for the computation dynamic characteristics of one of the centrifugal machine rotor models is drawn.

Experimental studies of the efficiency of high-speed ESPs

The purpose of the present research paper is to estimate the energy efficiency of ESP-operated low production rate wells (up to 100 m3/d).The data on pumps energy efficiency, including the high-speed ESPs, were consolidated and analyzed. The bench test of high-speed ESPs and comparison with field tests allowed to determine the efficiency adjustment factors and establish functional dependencies of energy parameters on shaft rotation speed;theobtainedcorrelations were suggested for recalculation of nominalvalues in bench tests. The paper also indicates that the average efficiency for the high speed ESPs is 12-17% higher in absolute values and 40-68% higher in relative values, compared with the efficiency of pumps with a nominal rotation speed of 3000 rpm. The suggested approach can be expanded as a methodology for wells with more complex operational conditions and more complex pump systems.

Design and Experiment of Stubble Chopping and Scattering Device Based on 2BMFJ-12 No-tillage Precision Planter

HighlightsA stubble chopping and scattering device based on 2BMFJ-12 no-tillage precision planter was modelled and developed.The optimal working parameters were obtained through theoretical analysis, flow field simulation, field test, and optimization combination test,The device improves the straw chopping and scattering ability of no-tillage planter.Technical support is provided for the development of conservation tillage equipment.Abstract.Aiming at the problems of poor stubble chopping quality of 2BMFJ-12 no-tillage precision planter, leading to slow stubble degradation rate, inconsistent seedlings emergence, and partial surface exposure, affecting tillage and crop yield at seedling stage, the stubble chopping and dispersal device was designed. The theoretical analysis of the corn stubble picking and chopping processes was carried out. The flow field characteristics in the volute were simulated by SolidWorks Flow Simulation. The main parameters and value range affecting the working performance of the device were determined. The orthogonal experiment method of three factors and three levels was used to carry out the field experiment with the angle of broken cutter, the rotation speed of cutter shaft and the inclination angle of negative pressure blade as the experiment factors, and the qualified broken rate, the uneven coverage, the scattering distance and the power consumption as the evaluation indexes. The variance analysis and optimization of the experiment results were carried out by Design-Expert 6.0.10. The optimized combination of parameters is that when the inclination angle of the chopping knife is -10.5°, the rotational speed of the knife shaft is 1120 r·min-1, and the inclination angle of the negative pressure blade is -15°, the qualified rate of chopping is greater than 93.01%, the coverage unevenness is less than 17.11%, the scattering distance is greater than 6.80 m, and the power consumption is less than 6.79 kW. The research results provide technical support for 2BMFJ no-tillage precision planter to improve stubble chopping and covering quality. Keywords: Corn stubble, No-tillage sowing, Scattering distance, Stubble broken, Uniform coverage.

An Active Control Excitation Method of Three-Stage Brushless Synchronous Starter/Generator in Electric Starting Mode for MEA

More electric aircraft (MEA) and all electric aircraft (AEA) are the development trends of new generation aircraft. With the increasing dependency on electrical power in MEA, dual-function electrical machinery technology is the inevitable trend of the aircraft engine-driven generator. This paper proposes an active control excitation method to the S/G to produce enough electromagnetic torque and realize the smooth electric starting of aircraft engine. The main DC/AC invertion module in the DC/AC inverter supplies a three-phase current to the main S/G stator windings. The module adopts an active control method that the current is adjusted by a reference three-phase current which varies as a function of rotor shaft position and rotation speed. Meanwhile, the exciter power supply module in the DC/AC inverter supplies a single-phase AC current to the auxiliary exciter stator winding. This part also adopts an active control method that a current hysteresis tracking control strategy is taken and the scheduled current is adjusted as a function of the rotor rotation speed. Simulation results verify the effectiveness of the electric starting excitation strategy. The two magnetic fields generated by the stator and rotor windings of the main S/G interacts each other which produces enough electromagnetic torque to drive the starter from the stationary state.

Laboratory Scale of Seed Damage of Coarse-Grain Depending on Groove Diameter and Depth in Roller Devices

HighlightsThe rate of damage to the bean seed by the grooved roller planter was determinedThe effects of planting speed, seed rate, groove diameter, and groove depth on seed damageThe most suitable groove diameter and depth were determined in bean plantingAbstract. Grooved roller planters can be used in the planting of small and large seeds when they are produced in the appropriate groove diameter and groove depth depending on the seed dimensions. In this study, the rate of damage to the dry bean seeds of the grooved roller device, which was modified and placed on the bottom of the warehouse of a grain planter, was investigated. Nine grooved rollers manufactured in different groove diameters (18, 20, and 22 mm) and groove depths (5, 8, and 11 mm) were tested at 80, 120, and 160 kg ha-1 seed rates and 8, 13, and 18 min-1 feed shaft rotation speeds. Breakage, crushing, and cracking in dry bean seeds were considered as damaged seeds. According to the results, the increase in the seed rate, feed shaft rotation speed, and groove depth reduced the seed damage rate. The increase in groove diameter increased the rate of seed damage. The lowest seed damage rate values were obtained at 160 kg ha-1 seed rate, 2 m s-1 forward speed, 18 mm groove diameter, and 11 mm groove depth. Keywords: Active groove length, Dry bean seed, Forward speed, Grooved roller, Seed rate.

Stepper Motor Control System for XY Module for IC Production

The presented in the paper control system of the stepper motor of the two-coordinate printing module is developed on the basis of modern elements and allows you to control the stepper motor, providing the required shaft rotation speed and adjusting the number of rotation steps. This system realizes the processing of a moving object in several coordinates simultaneously without kinematic elements that convert rotary motion into linear, which makes it possible to speed up the time and accuracy of the processing tool. A forked optical sensor is used as workpiece position sensors. UART and USB bus are used for communication with the computer.

Preparation of avocado leaf simplicia macro/nano particles by using high energy ball mill

Taguchi method was used to examine high energy ball mill characteristics when producing micro/nano-particles of Simplicia powder using Orthogonal Array (OA) L25. Two factors and five levels were selected for the smallest diameter. The average fineness of the powder produced by high energy ball mill was calculated using the ASTM E11 standard Retsch vibrating sieve machine. The smoothest’s fineness value was obtained at a working time of 30 minutes and a shaft rotation speed of 578 rpm with a powder fineness of 181μm. The coarsest fineness value was obtained at 10 minutes of working time and 488 rpm rotating speed with 336μm powder fineness. Obtained the smallest particle diameter has the potential for better absorption of nutrients into the body.

Efficient derivation of significant results from mechanical processing experiments with mixed solid waste: Coarse-shredding of commercial waste

Deriving significant experiment-based conclusions on mechanical processing of mixed solid waste is challenging: the input material cannot be downscaled in a way that enables drawing transferable conclusions from lab-scale experiments. Hence experiments need to be conducted in industry-scale, using real waste. Besides the enormous resulting experimental efforts and costs, which economically limit the number of experimental runs, identifying and quantifying significant effects is complicated by the distortion of the data introduced by the waste’s variability. The distortion is particularly high for cases where sampling is necessary and in experiments where material cannot be re-used from one run to the next. In the latter case, inter-experimental differences of the waste add to the distortion of the data. In this work, a systematic approach for deriving representative and significant results at the minimum possible effort is described and evaluated, based on the method of Design of Experiments. It is applied to a 32 runs D-optimal industry-scale coarse-shredding experiment with mixed commercial solid waste, based on a reduced cubic design model, examining the influence of the gap width, shaft rotation speed, and cutting tool geometry on the throughput behavior and energy demand. The resulting models are highly significant (model p-values < 0.0001), proving the ability to extract reliable information from industry-scale waste processing experiments. Concerning commercial waste shredding, the models provide new insights into process behavior, for example, the quadratic dependence of the mass flow on the shaft rotation speed, with the highest hourly mass flows at 84% of the maximum shaft rotation speed.

Construction of a Sensitive and Speed Invariant Gearbox Fault Diagnosis Model Using an Incorporated Utilizing Adaptive Noise Control and a Stacked Sparse Autoencoder-Based Deep Neural Network.

Gearbox fault diagnosis based on the analysis of vibration signals has been a major research topic for a few decades due to the advantages of vibration characteristics. Such characteristics are used for early fault detection to guarantee the enhanced safety of complex systems and their cost-effective operation. There exist many fault diagnosis models that have been developed for classifying various fault types in gearboxes. However, the classification results of the conventional fault classification models degrade when they are applied to gearbox systems with multi-level tooth cut gear (MTCG) faults operating under variable shaft speeds. These conditions cause difficulty in discriminating the gear fault types. Due to the improved computational capabilities of modern systems, the application of deep neural networks (DNNs) is getting popular in a variety of research fields, such as image and natural language processing. DNNs are capable of improving the classification results even when addressing complex problems such as diagnosing gearbox MTCG faults. In this research, an adaptive noise control (ANC) and a stacked sparse autoencoder–based deep neural network (SSA-DNN) are used to construct a sensitive fault diagnosis model that can diagnose a gearbox system with MTCG fault types under varying shaft rotation speeds, despite its complicatedness. An ANC is applied to gear vibration characteristics to remove a significant level of noise along the frequency spectrum of vibration signals to fix the most fault-informative components of each fault case. Next, the autoencoder learns the gear faults characteristic features from these fault-informative components to separate the fault types considered in this study. Furthermore, the implementation of the SSA-DNN is substituted for feature extraction, feature selection, and the classification processes in traditional fault diagnosis schemes by high-performance unity. The experimental results show that the proposed model outperforms conventional methodologies with higher classification accuracy.

Influence of blade vibration on part-span rotating stall

This paper presents the interaction between blade vibration and part-span rotating stall in a multi-stage high speed compressor. Unsteady aerodynamic and aeroelastic simulations were conducted using URANS CFD. Steady state computations showed short length scale disturbances formed local to the tip of a front stage rotor. Using a full annulus model, these disturbances were shown to coalesce into flow structures rotating around the annulus at approximately 76% of the shaft rotational speed. Natural evolution of the rotating stall did not result in a coherent spatial pattern. Sensitivity studies showed that operating point and tip clearance have significant impact on the developed state of rotating stall. Subsequent analyses carried out with prescribed rotor blade vibration showed a spatial ‘lock-in’ event where the circumferential order of the part-span rotating stall shifted to match that induced by the vibration mode. Moreover, in contrast to its natural form in the absence of vibration, the fully developed rotating stall showed a coherent stall signal. More importantly, it was found that numerical boundary conditions such as mixing plane and sliding planes can significantly influence the outcome of prediction.

The effect of porous round on waves produced on the wave simulation tool, laboratory scale

Bangka Island is one of the islands that has beautiful beach tourism destinations but also has the largest tin reserves in the offshore area. This causes a very significant difference and can be a gift or a curse. Waste from the results of offshore tin mining activities carried out by production suction vessels (KIP) in the form of mud and changes in seawater quality. Then the sludge produced by mining causes waste/mud to be carried by the waves of the sea and settles along the shore and imposes silting and causes seawater on the shore to become turbid. One way to determine the effect of waves on the deposition of mud, among others, with a wave simulation tool. The study aims to determine the length and height of the waves produced on a laboratory scale Floating Breakwater Simulation. From the results of the study it can be concluded that the shaft rotation speed affects the waves produced, the higher the shaft rotation the higher the resulting waves. The frequency of the simulation tool also increases while the wave period decreases as the rotation of the shaft rotates, which means that the resulting wave appears more frequently and with a high propagation speed at the highest rotation of the shaft.

Stochastic-resonance based fault diagnosis for rolling element bearings subjected to low rotational speed

Despite been introduced about more than 30 years ago, the Stochastic-Resonance (SR) theory has only been gaining considerable attention in the field of condition based maintenance (CBM) in recent years. SR is a nonlinear physical phenomenon where weak signals (i.e. signals with low signalto- noise ratio) can be enhanced by a cooperative interaction of noise and periodic excitation (stimulus) in particular nonlinear systems, e.g. “bistable” systems. In other words, SR serves as a non-linear filter that can amplify a (periodic) signal of interest heavily masked by a large background noise by adjusting both the parameters of the nonlinear bi-stable system and the intensity of artificially generated noise to be added to the measurement signal. This paper discusses an improvement of SR filtering with multi scale noise tuning recently published for multi-fault diagnosis of a rolling element bearing subjected to low rotational speed and low load. Prior to application of the SR filtering, gear-related signals are removed from a measured acceleration vibration signal (i.e. signal pre-whitening) by means of the cepstra-based discrete components removal. The pre-whitened signal is further processed by employing an optimized SR filter in which the filter parameters are pre-determined based on the faulty data. Finally, features defined as the ratio between the peaks around the corresponding bearing fault frequencies and the background noise level are extracted from the spectrum of the output signal obtained from the SR filtering. A number of experiments have been carried out on a gearbox dynamics simulator with healthy and faulty bearings in order to demonstrate and verify the effectiveness of the proposed approach for bearing fault detection under low shaft rotational speed (348 rpm) and low load (1.2 Nm). For comparison purpose, the experimental data have been analyzed both with the well known “envelope” method and the proposed framework. The experimental results show that the proposed framework outperforms the envelope method.

The Effect of Misalignment to Vibration, Electric Current and Shaft Rotation Speed on The Coupling Transmision

Coupling is one of the components are widely used in various industries. Coupling is widely used as a power transfer transmission. Coupling have a long life time, it mean coupling was damage if out of the maintenance. The one factor is misalignment. This study aim to determine the effect of misalignment on the coupling transmission to vibration, electric current and shaft rotation speed. In this study, was done alignment process with variations of misalignment on the coupling transmission and was done measurement value of vibration, electric current and shaft rotation speed. The study results show that the changed of misalignment would give a positive impact to vibration and electric current. For the effect misalignment to shaft rotation speed, the study results show that the changed of misalignment would give a negative impact to shaft rotation speed.

Rancang Bangun Sistem Kontrol dan Monitoring Data Turbin Angin Berbasis Website Menggunakan Raspberry Pi 3B+

Indonesia has considerable wind energy potential. Energy generation system performance can be monitored and controlled through the Internet of Things (IoT) technology. However, research and development of IoT technology in wind turbines in Indonesia is still low. Therefore, in this study, the author seeks to conduct research related to the development of a website-based wind turbine control and data monitoring system. This research uses a 3 blade horizontal axis wind turbine (NACA 2410). The monitoring system uses the Raspberry Pi 3B + microcontroller and several sensor devices such as the IR LM393 speed sensor to measure wind speed and shaft rotation speed, and the INA219 current-voltage sensor to measure the voltage and current of a 350 Watt DC generator. The website was created using the Laravel 5.8 PHP framework and Chart.js. Furthermore, the sensor calibration process and system testing are carried out. Based on the test results, it was found that the monitoring data system was functioning properly. The data has been successfully sent to the server and can be monitored in real-time via the website. Based on the results of the IR LM393 sensor calibration test, the linear regression equation y = 0.7881x + 13.837, and the value of R2 = 0.9934 is obtained. And the value of R2 = 0.9934 indicates that the sensor calibration process is well correlated. The results of testing the control system and monitoring of wind turbine data monitored through the website for 1 x24 show that the highest wind potential occurs at 13.00 to 14.00 WIB, namely at a wind speed of 3.74 m / s.