High Load Torque Research Articles

A design study on 20 kW class axial flux motor with HTS field winding for 100 MPa liquid hydrogen pump

This paper presents a design study of a low-speed, high torque 20 kW class motor with a high-temperature superconductor (HTS) field coil for a liquid hydrogen centrifugal pump. The motor is designed based on three key concepts: 1) employing an axial-flux motor topology that can increase torque density by reducing the axial length together with a centrifugal pump; 2) using liquid hydrogen in a pump as a coolant for HTS coil; 3) adopting no-insulation (NI) YBCO solenoid coils as field coils of the motor to improve coil protection as well as mechanical stability. In the design process, first, an electromagnetic design of the axial type motor is obtained considering the required performance of previous commercial pumps. Considering the current and temperature margin to secure the HTS coils' stable operation, two types of HTS coils (solenoid type and triangle type) are designed and their performances are compared. Second, to evaluate validity of the electromagnetic designs, mechanical stresses in the HTS coils are estimated. By comparing the solenoid type and the triangle type, it is confirmed that the solenoid type has a distinct stress-reducing effect in terms of magnetic stress as well as rotational stress. Our design study results show the potential superior performance of the axial flux motor with HTS coils for several tens of kW applications with low speed and high torque loads such as liquid hydrogen pumps.

High Torque and Increased Wear Redefine Gearbox Longevity in Electric Motors

This study explores the accelerated wear of gearboxes driven by electric motors compared to gearboxes in combustion engines, highlighting the important role of lubrication quality. The continuous operation of sugarcane processing machines requires durable gearboxes, especially under the high torque load of electric motors. By analyzing gearbox wear through standard load tests and various lubricant qualities, the findings reveal that superior lubricants significantly reduce wear. These results not only demonstrate the need for customized gearbox designs for electric motors, but also show that improvements in lubrication practices can extend gearbox life and increase efficiency in industrial applications globally. Highlights: Continuous operation vital for production targets. Electric motorbike gearboxes need frequent maintenance. Quality lubrication crucial for gearbox longevity. Keywords: Gearbox, Grind, Sugar Factory

Research on complex vector quasi-resonant control methods for permanent magnet synchronous motor

A complex vector quasi-resonant controller is proposed to solve the current controller’s dynamic coupling problem and static harmonics. Although current feedforward decoupling has been widely used, the calculation relies on the motor parameters. When the motor works at high speed and high torque load, the parameters change greatly, failing to decouple. In the static conditions, due to the inverter nonlinearity, the PMSM stator current contains lots of high harmonics, which causes the motor produces a specific frequency torque ripple. Therefore, complex vector quasi-resonance is proposed. The complex vector transfer function contains a virtual axis zero point, which varies with speed so that the zero point of the controller and the pole of the controlled object are eliminated. The quasi-resonant controllers are connected in parallel with the main controller and suppress harmonics at fixed frequencies of the system. The method is based on the resonant controller with infinite gain at the resonant frequency point, which can achieve zero steady-state error tracking, achieving the purpose of torque pulsation suppression. In this paper, through theoretical derivation and algorithm structure design, the algorithm’s effectiveness is verified in the simulation. The proposed algorithm has a fast response in the dynamic state and smaller current harmonics in the steady state.

Numerical Investigation of Evaporation Modelling for Different Diesel Fuels at High Temperature and Pressure in Diesel Engine

Diesel engines are used widely in the world due to their capability of handling high torque and heavy loads efficiently. Fuel injection systems in the diesel engine have different processes that affect the complete burning of fuel in the combustion chamber. These include the primary and secondary breakup of liquid fuel droplets and evaporation. Diesel engines use the air as a working substance only. One of the processes is the evaporation of fuel droplets. Complete evaporation of diesel fuel liquid in the combustion chamber is a prerequisite for complete combustion. Hence evaporation of droplets has an impact on the efficiency of the engine and consequently on the output power and torque. In the present paper evaporation of two different diesel fuels is modeled numerically taking into account the turbulence effects present in the cylinder due to high temperature and pressure using the RANS turbulence model. Evaporation of n-heptane diesel fuel and n-decane is controlled by the numerical model that includes the conservation equations of mass, energy, momentum and species transport. During the evaporation phase heat is transferred to the droplet and due to evaporation from the surface of the droplet, the mass of evaporating droplets is decreased. These two processes are controlled by the equations of the Discrete Phase Model present in the Fluent. Then the results are plotted by varying the droplet diameter and temperature. Results include the decay in droplet diameter, increase in the droplet temperature effect on the velocity of droplet and temperature changes in the cylinder due to evaporation of fuel. There are different parameters which affect the rate of evaporation of fuel droplets inside the engine cylinder of an internal combustion engine. These parameters include the diameter of fuel droplets, initial temperature of fuel droplets, and the temperature inside the cylinder after the compression stroke and surface area of droplets. Small droplets need a short time to evaporate while if the size of droplets is large then evaporation times is also increased.

A Comparison of Knowledge and Skills Related to Up-to-Date Implant Techniques Among Prosthodontists, Periodontists, and Oral Surgeons: A Cross-Sectional Study.

Background A dental implant is used in the treatment of complete and partial edentulism. Implant application has increased significantly in modern dentistry. The anatomy, medical condition, practitioner knowledge, and surgical technique are key factors that eventually affect the overall outcome of dental implants. For a better treatment outcome for dental implants, adequate multidisciplinary communication, cooperation, and support must be achieved while considering the periodontics, prosthodontics, and oral surgery specialties. Objective This study aims to compare the knowledge and skills regarding up-to-date implant techniques among prosthodontists, periodontists, and oral surgeons in Riyadh, Saudi Arabia. Materials and methods The data were collected from prosthodontists, periodontists, and oral surgeons working in Riyadh, Saudi Arabia from April 2022 to August 2022. The targeted subjects were residents, specialists, and consultants working in Riyadh, Saudi Arabia. Results A total of 181 dentists were surveyed in the current study. A significantly higher proportion of oral surgeons have perceived that the BTI brand (BTI Biotechnology Institute, Álava, Spain) had a high load torque before screw fracture (p = 0.025). Periodontists had significantly higher knowledge levels related to the technique with the lowest marginal bone loss (p = 0.003). Knowledge levels were significantly higher among prosthodontists for the items related to the fact that both early and late implant placement following alveolar ridge placement would have the least changes in periodontal parameters (p = 0.013). Conclusion All the targeted specialties exhibited a comparable impression regarding implant techniques and their outcomes. Each specialty had its own aspect of treatment during the placement of dental implants depending on multiple factors. Significant knowledge was observed from each specialty regarding implant brands, techniques, and antibiotic prescriptions for dental implants.

Walsh–Hadamard Domain-Based Intelligent Online Fault Diagnosis of Broken Rotor Bars in Induction Motors

Mechanical failures are the most common defects in induction motors (IMs). They derive from the continuous starts and stops with high-load torque. They can cause interruptions in production lines with great economic losses. Therefore, online monitoring systems, allowing a continuous monitoring for fault diagnosis in early stages, have been intended for many researches in last years. Broken rotor bars (BRBs) are common failures, which are among the most difficult to detect since the induction motor works with apparent normality without giving any signal about the defect. Several methodologies have been proposed to detect BRBs in IMs. However, they require high-computational-complexity algorithms for parameterizing the current signal, making it difficult to achieve an online implementation of the corresponding monitoring system. Hence, aiming to overcome the limitations provoked by complex parameterizations of the current signal and to improve the fault classification accuracy, in this work, a novel methodology, based on a hardware processing system implemented on a field-programmable gate array (FPGA), for electric current signal analysis in the Walsh–Hadamard domain is proposed to achieve online intelligent BRB diagnosis. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> -nearest neighbors ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> -NN) algorithm is used for classifying different operational conditions from the Walsh–Hadamard transform (WHT) of the electric-current signal. Experimentally obtained results from applying the proposed method on acquired real data demonstrate that the introduced approach reaches a remarkable high efficiency on detecting and classifying BRBs.

A dynamic model for the investigation of twisting effect in long flux‐ switching PM motors in ESPs

Shaft twisting occurs along the length of electric motors rotors. The twisting depends on the shaft properties and the transmitted torque. In Electrical Submersible Pumps, due to the high ratio of length to the diameter of the motor and the high load torque, the twisting effect occurs significantly. Thus, when such a condition emerges for an electric motor, the electromagnetic torque is not uniformly produced along the motor length, since shaft twisting results in rotor position variation with respect to the stator. Therefore, the twisting and the produced electromagnetic torque of the motor are interdependent. It means that these two issues cannot be studied separately and a model must be proposed to consider them together so that the electromagnetic performance of the motor can be studied under such conditions. Despite the importance of modeling the twisting effect for the electric motor, this issue has never been investigated before. In this article, a novel dynamic model for the flux-switching permanent magnet motor is proposed by which the shaft twisting effect is simulated to study the motor performance. Eventually, the twisting effect during startup and steady-state are studied as well as the effect of shaft diameter and motor length on shaft twisting. To evaluate the model, it is compared with the verified steady-state model for the flux-switching permanent magnet motor with the twisted shaft obtained from another article, and also results obtained by finite element analysis.

Study on real-world power-based emission factors from typical construction machinery

Construction machinery accounts for a large share of the non-road machinery market and is an important pollutant source. In this study, real-world emission tests were undertaken on 16 excavators and 19 wheel loaders by using a portable emission measurement system (PEMS) to obtain their real-world engine performance and emission factors. The typical operating modes were categorized as idling, moving and working modes. The results show that in the working mode, the engine continuously operated at a high speed, high torque and high load factor, which led to sharp up and down CO, HC, NOx and particle number (PN) emissions. As the emission standards were strengthened, the CO, HC and NOx emissions clearly decreased, and the excavators and wheel loaders showed a higher emission level in the moving mode. A comparison of the excavator and wheel loader in China III displayed that the CO, HC, and NOx total emission factors of the wheel loader were 10.20, 2.70 and 1.79 times higher than those of the excavator, respectively, so the wheel loader contributed more seriously to environmental pollution. The CO and HC measured emission factors of the excavators and wheel loaders were 0.05-1.38 times and 0.13-0.58 times higher than the corresponding Limitation and the recommended values from the national emission inventory Guideline. However, the NOx emission factors were 1.20-3.25 times higher than the corresponding Limitation and the recommended value from the Guideline, which means that the recommended values overestimate CO and HC, and underestimate NOx. A comparison of the emission factors of the excavators and wheel loaders in this study with others demonstrate that the CO and HC power-based emission factors were generally lower, but the NOx emission factor was higher.

Start-up of large power electric motors with high load torque

Start-up of large power electric motors with high load torque

Fatigue life improvement on 20MnCr5 steel through surface modification for auto transmission application

This research represents a unique approach in improving the fatigue life of 20MnCr5 (89–91 HR15N hardness) shafts which were surface treated through gas carburizing process in a sealed quench furnace followed by double tempering. Crack initiation on 20MNCr5 transmission shafts always occurs at the end of spline location (Location X), propagates longitudinally and finally ruptures at stem location. This was confirmed through optical microscope and SEM (make:Jeol) images. The fatigue experiments were carried out at room temperature in 11,500Nm torque test machine (Model – MTS-663-144-01). The torque test was carried-out by applying a fully reversed cyclic load with the frequency of 5Hz for the torsional load of ±3000Nm. Effect of double tempering, surface roughness, carbon case depth, Microstructure such as retained austenite and non-martensitic transformation products (NMTP) have been investigated in this research. The outcome of the research shows that increase in case depth (CD) (out of increased gas carburising time) resulting in increased inter-granular oxidation (IGO) and NMTP in its microstructure. The presence of retained austenite on the surface of the shaft has not yielded any remarkable improvement in fatigue life of the shaft. Presence of tempered martensite with lesser percentage of retained austenite on the surface improved the fatigue life drastically from 12,000 cycles to greater than 35,000 cycles at high torque load of ±3000Nm.

CAMBIAR LOS ACOPLAMIENTOS DE ENGRANAJE POR ACOPLAMIENTOS ELASTOMÉRICOS EN ENTORNOS DIFÍCILES

Although go unnoticed, the couplings have always been essential to facilitate the transfer of power in all kinds of machines and equipment. The Gear Couplings, a type of flexible coupling, are especially popular in industrial applications, which allow you to transmit high torque loads and tolerate moderate misalignment.

Determination of the contact stresses in double-row tapered roller bearings using the finite element method, experimental analysis and analytical models

Double-row Tapered roller bearings (TRBs) are mechanical devices that are designed to support high axial, radial and torque loads. This combination of loads produces high contact stresses on the bearing raceways that are difficult to predict and validate experimentally, and can cause defects like pitting and fatigue spalling. In response, theoretical models have been proposed by many researchers to calculate the approximate distribution of contact stresses over the bearing raceways. More recently, numerical methods that are based on the Finite element method (FEM) have been used to obtain the contact stresses, although this method requires that the mesh size first be adjusted. This paper shows a process for adjusting a double-row TRB Finite element (FE) model. It is based on generating successive nonlinear FE submodels to calculate the distribution of contact stresses. A theoretical model and contact pressure sensors were used to adjust and validate the Finite element (FE) model.

To Arrive At Solution for Profile Distortion ProblemEncountered During Heat Treatment Process of GearManufacturing Using Root Cause Analysis

Gear Box, assemblies and hence quality of its components(referring to gears) play a vital role during transmission mechanism. Many issues have occurred and still do occur during the processing of gears especially in areas of Hobbing , Shaving, Heat Treatment processes, etc and best trials have been carried out so as to attain authentic solutions to the complexities occurred. Oerlikon Fairfield- a gear manufacturing MNC successfully uses Root Cause Analysis Techniques( PDCA cycle, Cause and Effect Diagram with Shainin Technique combination), DMAIC quality improvement Methodology in order to solve the problems encountered during part processing . The present paper deals with Profile fall/distortion problem occurring after heat treatment process during new development of helical gear. Modern gearboxes are characterized by high torque load demands, low running noise and compact design. In order to fulfill these requirements, profile specifications have to be tightly controlled. Current problem being one of major quality issues is resolved and controlled by using a combination of Cause and Effect Diagram with Shainin Technique and DMAIC-6 sigma break through methodology. Tool modifications being considered as final resort and hence implementation of modifications of shaving cutter during shaving stage (a pre heat treatment process) helped in achieving the required profile trace within the required post heat treatment process specifications.

Development of a new hollow sucker rod family for rotating pumping (progressive cavity pump systems)

Abstract Conventional solid sucker rods according to API 11B specification are widely used for rotating pumping, particularly to drive PCP Systems (progressive cavity pump systems) during the oil production. However, these products have been developed to work under axial alternating loads, and not under torsional loads. Thus, the use of these rods for rotating pumping has several limitations and disadvantages like a low yielding torque, insufficient backspin and fatigue resistance, showing low performance and resulting in high operative costs for artificial lift systems. Furthermore, the PCP System requires higher torque to work efficiently. For that reason, it is suitable to develop a new product with better performance to be used for this pumping system. This paper presents the development of a family of innovative products called “Hollow Sucker Rod” as a technical solution for PCP System. The development consisted of (i) design of the connection, (ii) manufacture of prototypes, (iii) full scale lab tests, and (iv) field trials. Some advantages of this new technology are: (i) high torque load to yielding, (ii) good fatigue resistance, (iii) high backspin resistance, (iv) less tubing wear, (v) increase in pumping rates, (vi) possibility to inject different kind of fluids by the inside of the “Hollow Sucker Rod”, and (vii) easy to make up and install (conventional pulling ring).

Exploit of Shipping Auxiliary Swing Test Platform

Shipping auxiliary swing test Platform is a kind of test device which can complete performance tests of the ship auxiliary equipment by simulating the motion of ships in the laboratory environment. This article presented a swing test-bed with high torque dynamic load of three-degree of freedom (3-DOF), simulated mainly the motion of rolling, pitching and heaving in a specific sea state. Put forward some comparison and design of the structure schemes against the requirement of high torque load, choose the best scheme according to the test requirement, and introduce some key accessories design of the made reliability accounting on the key mechanical structure of the swing test-bed.

Design and Application of Large Torque Electrical Load Simulator

In order to meet the testing requirement of positive and reverse operation large torque load for new rudder, an electrical load simulator is designed. The system mathematical model is established and the feedforward compensation control of torque and rudder angle is adopted to restrain the surplus torque according to the principle of invariance. The high precision large torque load under positive and reverse operation for rudder is realized by torque and position hybrid control. The practical application shows that the proposed method can effectively restrain surplus torque and the system meets the high precision torque load under positive and reverse operation for rudder very well.

Change in Backlash of Humanoid Robot Joints under High Load

In this work, wear of reinforced poly-ether-ether-ketone (PEEK) polymer bushes in friction against 7075 aluminium alloy cam plates or titanium crankshafts is investigated in order to establish the application possibilities in transmission parts in humanoid robot joints under high load torque. The PEEK bush wear requires close examination as well as the input axis-output axis transmission error (backlash). Sliding wear tests were performed on bushes under 4000 kgfcm (392 Nm) load torque, while the cam plate oscillated in the humanoid robot leg joint evaluation system. The robot joint using PEEK bush achieved quite small backlash after the fatigue wear test.

Theoretical modelling and experimental identification of nonlinear torsional behaviour in harmonic drives

The demand for accurate and reliable positioning in industrial applications, especially in robotics and high-precusion machines, has led to the increased use of harmonic drives. The unique performance features of harmonic drives, such as high reduction ratio and high torque capacity in a compact geometry, justify their widespread application. However, nonlinear torsional compliance and friction are the most fundamental problems in these components, manifesting themselves as a combination of stiffening spring together with hysteresis at reversal points. Accurate modelling of the static and dynamic behaviour is expected to improve the performance of the system.This paper offers a model for torsional compliance of harmonic drives. A statistical measure of variation is defined, by which the reliability of the estimated parameters for different operating conditions, as well as the accuracy and integrity of the proposed model, are quantified. The model performance is assessed by simulation to verify the experimental results.Two test setups have been developed and built, which are employed to evaluate experimentally the behaviour of the system. Each setup comprises a different type of harmonic drive, namely the high load torque and the low load torque harmonic drive. The results show an accurate match between the simulation torque obtained from the identified model and the measured torque from the experiment, which indicates the reliability of the proposed model.

Preparation and characterization of fusion processed solid dispersions containing a viscous thermally labile polymeric carrier

The primary aim of the present study was to investigate the ability of hydroxypropyl and methoxyl substituted cellulose ethers to stabilize supersaturated concentrations of itraconazole (ITZ), a poorly water-soluble weak base, after an acid-to-neutral pH transition. A secondary aim of the study was to evaluate the effect of fusion processes on polymer stability and molecular weight. Polymer screening studies showed that stabilization of ITZ supersaturation was related to the molecular weight of the polymer and levels of hydroxypropyl and methoxyl substitution. METHOCEL E50LV (E50LV), which is characterized as having a high melt viscosity, was selected for solid dispersion formulation studies. Hot-melt extrusion processing of E50LV based compositions resulted in high torque loads, low material throughput and polymer degradation. KinetiSol Dispersing, a novel fusion based processing technique, was evaluated as a method to prepare the solid dispersions with reduced levels of polymer degradation. An experimental design revealed that polymer molecular weight was sensitive to shearing forces and high temperatures. However, optimal processing conditions resulted in significantly reduced E50LV degradation relative to HME processing. The technique was effectively utilized to prepare homogenous solid solutions of E50LV and ITZ, characterized as having a single glass transition temperature over a wide range of drug loadings. All prepared compositions provided for a high degree of ITZ supersaturation stabilization.

Line-Start Permanent-Magnet Machines Using a Canned Rotor

Various line-start permanent-magnet (PM) machines have been around for many years: these offer the advantages of line-starting as an induction machine and running synchronously as a PM machine, both from a fixed-frequency supply. The major disadvantage is the uncertainty of successful synchronization, particularly with loads combining high inertia with high load torque. Virtually all conventional line-start PM machines use a cage-type induction winding embedded into the rotor along with the magnets. This paper describes an unusual variant of this type: comprising a very simple rotor construction of surface-mounted rotor magnets contained within an annular conducting rotor can which acts as the induction winding but can also provide environmental containment if the application requires it. The purpose of this paper is to describe the canned motor concept in detail so that its potential for other motor/drive applications can be assessed. This paper also develops and describes an analytical dynamic electromechanical model using ldquolayer theory.rdquo Experimental results demonstrating successful operation of a 2.5-kW prototype machine are presented together with the simulated results using the dynamic model. The influence of certain key design features on the synchronization process is also included.