Non-contact Transmission Research Articles

Dynamic model of magnetic transmission

In the work, a non-contact electromechanical energy converter with permanent magnets, which is known as magnetic transmission, is studied. Magnetic transmissions have certain structural advantages compared to mechanical transmissions, namely: high reliability, efficiency, lower losses, non-contact transmission of mechanical power, no maintenance costs, and simplicity of construction. The use of magnetic transmissions for systems of conversion of low-potential mechanical energy into electrical energy is especially relevant: wind energy, water energy, energy of mechanical vibrations, etc. The use of magnetic gearboxes in autonomous wind power plants can be more promising from an economic and technical point of view compared to traditional mechanical transmissions. A numerical simulation mathematical model of magnetic transmission with permanent magnets has been developed. The use of magnetic transmission, for example, for autonomous wind power systems allows to increase the reliability of the operation of such installations, reduce operating costs and increase the efficiency of their operation. In emergency modes of operation, the use of magnetic transmission allows to avoid destruction or emergency shutdowns of electrical equipment. The developed simulation model of magnetic transmission takes into account the pulsations of the electromagnetic moment due to the discrete structure of the magnetic transmission and the change of the model parameters when the input moment changes: pulsations, losses in the magnetic core and permanent magnets, the change of the load angle and the transmitted electromagnetic moment. A feature of the developed model of the magnetic transmission system is that a change in the load of the electric power source leads to a change in the operating point on the mechanical characteristics of the rotor of the wind turbine. Conversely, when the wind parameters change, the output parameters of the source of electrical energy change: power, voltage, current and electromagnetic moment.

One-way thermomagnetic simulation of magnetic coupling in natural gas pressure energy utilization

ABSTRACT Magnetic coupling is an approach employed to prevent gas leakage by transforming the dynamic seal into a non-contact static seal for the recovery of natural gas pressure energy. The impact of thermal demagnetization necessitates the consideration of the heat dissipation characteristics resulting from eddy current losses in the rotating magnetic field. We performed a numerical study of thermal-magnetic coupling in a magnetic transmission validated by experimental results. The Maxwell software was utilized to simulate the distribution characteristics of induced current, while the Fluent software was employed to analyze the dissipation of heat caused by eddy currents. The obtained simulation results reveal a proportional increase in induced current and eddy current losses with the rotation speed. Also, the eddy current losses increase together with the thickness of the isolation cover, since more volume of the conducting media is affected by the eddy currents. Furthermore, reducing the electrical conductivities of the isolation cover and enhancing the internal flow rates can effectively decrease the temperature of the magnetic coupling and mitigate thermal demagnetization. These research findings offer valuable insights for the design and optimization of non-contact transmission methods, ultimately enhancing the safety of natural gas top-pressure energy recovery equipment.

Low-stiffness comfort shift characteristics of a permanent magnet two-speed transmission for low-speed EV

Jerk during shift in mechanical two-speed transmissions often have a serious impact on driving comfort. Within this paper, a proposed two-speed permanent magnet transmission is presented for low-speed electric vehicles, which utilizes magnetic non-contact transmission. This transmission is composed of a magnetic drive mechanism, a clutch, and a selectable one-way clutch. Then, a mathematical model is established for the magnetic-machine composite transmission based on the principles of magnetic field modulation and the concentrated parameter method. Additionally, a shift method that operates without power interruption is presented. Finally, the process of shifting is simulated for permanent magnet drive systems with varying magnetic coupling stiffness in a MATLAB/Simulink environment. The resulting torque calculations are compared with those obtained from the commercial software Maxwell. Simulation results indicate that the two-speed permanent magnet transmission does not experience power interruption during upshifting. Less jerk when shifting gears. Low magnetic coupling stiffness can reduce high-frequency vibration and enhance shift comfort. The findings from the torque calculations obtained through the proposed model align with those obtained from the commercial software Maxwell.

Parapoxvirus-based therapy eliminates SARS-CoV-2-loaded fine aerosol and blocks viral transmission in hamster models.

Currently, it is believed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an airborne virus, and virus-containing aerosol particles have been found concurrent with the onset of COVID-19, which may contribute to the noncontact transmission of SARS-CoV-2. Exploring agents to block SARS-CoV-2 transmission is of great importance to prevent the COVID-19 pandemic. In this study, we found that inactivated Parapoxvirus ovis (iORFV), a kind of immunomodulator, could compress the proportion of small particle aerosols exhaled by Syrian golden hamsters. Notably, the concentration of SARS-CoV-2 RNA-containing aerosol particles was significantly reduced by iORFV in the early stages after viral inoculation. Importantly, smaller aerosol particles (<4.7 μm) that carry infectious viruses were completely cleared by iORFV. Consistently, iORFV treatment completely blocked viral noncontact (aerosol) transmission. In summary, iORFV may become a repurposed agent for the prevention and control of COVID-19 by affecting viral aerosol exhalation and subsequent viral transmission.

Pathogenicity, transmissibility, and fitness of SARS-CoV-2 Omicron in Syrian hamsters.

The in vivo pathogenicity, transmissibility, and fitness of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant are not well understood. We compared these virological attributes of this new variant of concern (VOC) with those of the Delta (B.1.617.2) variant in a Syrian hamster model of COVID-19. Omicron-infected hamsters lost significantly less body weight and exhibited reduced clinical scores, respiratory tract viral burdens, cytokine and chemokine dysregulation, and lung damage than Delta-infected hamsters. Both variants were highly transmissible through contact transmission. In noncontact transmission studies Omicron demonstrated similar or higher transmissibility than Delta. Delta outcompeted Omicron without selection pressure, but this scenario changed once immune selection pressure with neutralizing antibodies-active against Delta but poorly active against Omicron-was introduced. Next-generation vaccines and antivirals effective against this new VOC are therefore urgently needed.

Electromagnetic performance analysis of the umbrella shaping inner rotor coaxial magnetic gear with dual modulation rings

The coaxial magnetic gear is a new type of noncontact transmission mechanism, which avoids the inherent defects of the mechanical gearbox due to gear meshing transmission. To study a coaxial magnetic gear (CMG) with high torque density and low torque ripple to replace the mechanical gear in the semidirect drive wind turbine, a novel umbrella shaping inner rotor CMG (US-CMG) with an auxiliary modulation ring is proposed in this paper. The novel structure adopts a CMG with a dual modulated ring to increase the electromagnetic torque. In addition, the magnetic block of the poled inner rotor is divided into three pieces magnetized by Halbach arrays, and the middle piece is umbrella-shaped to reduce torque ripple. Based on the topology of the US-CMG and the principle of the magnetic field modulation, the operation mechanism of the US-CMG is analyzed. A contrastive analysis among the US-CMG, Halbach magnetized dual-modulator CMG (HM-CMG), and surface-mounted CMG (SM-CMG) is established to identify the performance of the US-CMG. Compared with the SM-CMG, the results show that the electromagnetic torque of the US-CMG has increased by 65.46%, and the torque ripple of the US-CMG is 57.6% of that of the SM-CMG.

Optimal Design of a Novel Magnetic Twisting Device based on NSGA-II Algorithm

Abstract This paper presents a novel magnetic twisting device with a coaxial double rotor based on non-contact transmission characteristics of magnetic drive technology. When the twisting device rotates one cycle, the yarn can get triple twists. This means the new device can twist three times more than what the traditional single twist does. The structure of the magnetic twisting device is designed according to the twisting principle. The influence of main structural parameters on the magnetic torque is analyzed. To optimize the maximum transmission torque and the minimum magnet volume, the multi-objective optimization design model for the twisting device is established. Main parameters such as the relative angle of active disc assembly and passive disc assembly, the thickness of magnet, and the average radius of the magnet distribution are optimized by NSGA-II algorithm. Optimization results show that the proposed structural optimization design of a twisting device based on the magnetic drive has excellent performance and is effective for industrial application.

Design of Transmitting Antenna for Aero-engine Telemetry Information Transmission System

Abstract The demand of aero-engine for non-contact telemetry information transmission is very urgent. Based on the analysis of the characteristics of aero-engine telemetry information transmission system, the rotor disk and stator disk suitable for near-field communication under high centrifugal load are designed in this paper. In order to ensure the stable transmission of telemetry information under large angular displacement between rotor disk and stator disk, two circular arc-shaped dipole antennas are designed to be symmetrically installed on rotor disk for telemetry information transmission. The designed pair of arc-shaped dipole antennas are fabricated and measured. The measurement results show that the two transmitting antennas resonate at 2.19GHz and 2.27GHz respectively, and their impedance bandwidth of -10dB is 35MHz and 34mhz respectively. In their operating frequency band, the isolation between them is greater than 38dB, and their performance fully meets the needs of aeroengine telemetry information transmission.

Design of Wireless Charging Coils for Aero-engine Telemetry Information Transmission System

Abstract In order to meet the need of non-contact transmission of aero-engine telemetry information, first of all, a rotor disk and a stator disk suitable for near field communication are designed in this paper, then, the coil design of wireless charging system suitable for high centrifugal force load is carried out. The designed single charging coil can charge two receiving coils at the same time. In order to eliminate the influence of aluminum alloy rotor disk and stator disk on charging performance, concave ferrite slots are installed on rotor disk and stator disk respectively to shield charging coil and receiving coil. The designed charging coils are fabricated and integrated with rotor disk and stator disk respectively. Finally, the designed charging coil and receiving coils are connected into the charging system for testing. The test results show that the charging coil and receiving coils are completely matched with the charging circuit and receiving circuit, and their performance can fully meet the use requirements of aeroengine telemetry information transmission system.

Analysis of electromagnetic performance of differential multi-stage coaxial magnetic gears with large gear ratio and high torque density applied to high-power wind turbines

Magnetic gear is a non-contact transmission mechanism, which overcomes the drawback of mechanical gear transmission. Although the series multi-stage magnetic gear can provide a large gear ratio compared to the single-stage magnetic gear, the lower torque density of the series multi-stage magnetic gear limits its use in high-power wind turbines. According to the magnetic gear field modulation mechanism and the differential transmission method, a differential multi-stage coaxial magnetic gear transmission device is proposed, which can achieve transmission with a large gear ratio and large torque density. Based on the differential multi-stage coaxial magnetic gear structure and its working principle, the finite element method is used to simulate the electromagnetic performance of the multi-stage coaxial magnetic gear. Futhermore, the electromagnetic performance of the two stages of the proposed magnetic gear are compared. The results show that there is a significant difference between the the electromagnetic performance of the first stage and that of the second stage. The torque ripple of the first stage is more dramatic than that of the second stage. The torque ripple amplietude of the inner rotor of the first stage is 5.08‰ larger than that of the second stage. The torque ripple amplietude of the outer rotor of the first stage is 4.591‰ larger than that of the second stage.

Analysis of Electromagnetic Performance of Modulated Coaxial Magnetic Gears Used in Semi-Direct Drive Wind Turbines

Wind turbine is a key device to realize the utilization of wind energy, and it has been highly valued by all countries. But the mechanical gear transmission of the existing wind power device has the disadvantages of high vibration and noise, high failure rate, and short service time. Magnetic field modulation electromagnetic gear transmission is a new non-contact transmission method. However, the conventional modulation magnetic gear has low torque density and torque defects with large fluctuations. In order to overcome the gear transmission problems of the existing semi-direct drive wind power generation machinery and improve the electromagnetic performance of the traditional magnetic gear transmission, this paper proposes a new transmission scheme of a non-contact semi-direct drive wind generator with a surface mount Halbach array modulated magnetic gear method, and considers the electromagnetic properties of the semi-direct drive modulation magnetic gear of the wind turbine. The finite element software is used to construct the model of the surface-mounted Halbach array magnetic gear and the conventional gear, analyzed the distribution of magnetic field lines of the two magnetic gears, calculated the air gap magnetic flux density of the inner and outer air gap, and obtained the main harmonics of the inner and outer air gap magnetic density; calculated the static torque and steady-state operating torque of the inner and outer rotors in the model, compared the air gap flux density, harmonics and torque of the magnetic gears. The simulation results show that the magnetic field modulation type magnetic gear of the surface mount Halbach array magnetic gear method improves the magnetic induction waveform of the inner and outer air gap, reduces the pulse torque fluctuation, and has a 60% higher static torque. Applying it to semi-direct drive wind power generation equipment not only overcomes the shortcomings of mechanical gears, but also has higher electromagnetic performance. Therefore, the surface-mounted Halbach array modulated magnetic gear can be used to replace the mechanical gearbox in the semi-direct drive wind power generation equipment.

TL-Net: A Novel Network for Transmission Line Scenes Classification

With the development of unmanned aerial vehicle (UAV) control technology, one of the recent trends in this research domain is to utilize UAVs to perform non-contact transmission line inspection. The RGB camera mounted on UAVs collects large numbers of images during the transmission line inspection, but most of them contain no critical components of transmission lines. Hence, it is a momentous task to adopt image classification algorithms to distinguish key images from all aerial images. In this work, we propose a novel classification method to remove redundant data and retain informative images. A novel transmission line scene dataset, namely TLS_dataset, is built to evaluate the classification performance of networks. Then, we propose a novel convolutional neural network (CNN), namely TL-Net, to classify transmission line scenes. In comparison to other typical deep learning networks, TL-Nets gain better classification accuracy and less memory consumption. The experimental results show that TL-Net101 gains 99.68% test accuracy on the TLS_dataset.

Surgical Mask Partition Reduces the Risk of Noncontact Transmission in a Golden Syrian Hamster Model for Coronavirus Disease 2019 (COVID-19).

BackgroundCoronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is believed to be mostly transmitted by medium-to-large sized respiratory droplets although airborne transmission is theoretically possible in healthcare settings involving aerosol-generating procedures. Exposure to respiratory droplets can theoretically be reduced by surgical mask usage. However, there is a lack of experimental evidence supporting surgical mask usage for prevention of COVID-19.MethodsWe used a well-established golden Syrian hamster SARS-CoV-2 model. We placed SARS-CoV-2-challenged index hamsters and naïve hamsters into closed system units each comprising two different cages separated by a polyvinyl chloride air porous partition with unidirectional airflow within the isolator. The effect of a surgical mask partition placed in between the cages was investigated. Besides clinical scoring, hamster specimens were tested for viral load, histopathology, and viral nucleocapsid antigen expression.ResultsNon-contact transmission was found in 66.7% (10/15) of exposed naïve hamsters. Surgical mask partition for challenged index or naïve hamsters significantly reduced transmission to 25% (6/24, P=0.018). Surgical mask partition for challenged index hamsters significantly reduced transmission to only 16.7% (2/12, P=0.019) of exposed naïve hamsters. Unlike the severe COVID-19 manifestations of challenged hamsters, infected naïve hamsters had lower clinical scores, milder histopathological changes, and lower viral nucleocapsid antigen expression in respiratory tract tissues.ConclusionsSARS-CoV-2 could be transmitted by respiratory droplets or airborne droplet nuclei in the hamster model. Such transmission could be reduced by surgical mask usage, especially when masks were worn by infected individuals.

Influence of shapes and dimensions of pole piece on conveyance load in non-contact linear transmission mechanism

Influence of shapes and dimensions of pole piece on conveyance load in non-contact linear transmission mechanism

Design, test and numerical simulation of a low-speed horizontal axis hydrokinetic turbine

A small-scale horizontal axis hydrokinetic turbine is designed, manufactured and studied both experimentally and numerically in this study. The turbine is expected to work in most of China's sea areas where the ocean current velocity is low and to supply electricity for remote islands. To improve the efficiency of the turbine at low flow velocities, a magnetic coupling is used for the non-contacting transmission of the rotor torque. A prototype is manufactured and tested in a towing tank. The experimental results show that the turbine is characterized by a cut-in velocity of 0.25 m/s and a maximum power coefficient of 0.33, proving the feasibility of using magnetic couplings to reduce the resistive torque in the transmission parts. Three dimensional Computational Fluid Dynamics (CFD) simulations, which are based on the Reynolds Averaged Navier–Stokes (RANS) equations, are then performed to evaluate the performance of the rotor both at transient and steady state.

Design and Numerical Simulations of a Flow Induced Vibration Energy Converter for Underwater Mooring Platforms

Limited battery energy restricts the duration of the underwater operation of underwater mooring platforms (UMPs). In this paper, a flow-induced vibration energy converter (FIVEC) is designed to produce power for the UMPs and extend their operational time. The FIVEC is equipped with a thin plate to capture the kinetic energy in the vortices shed from the surface of the UMP. A magnetic coupling (MC) is applied for the non-contacting transmission of the plate torque to the generators so that the friction loss can be minimized. In order to quantify and evaluate the performance of the FIVEC, two-dimensional computational fluid dynamics (CFD) simulations are performed. Simulations are based on the Reynolds Averaged Navier-Stokes (RANS) equations and the shear stress transport (SST) k-ω turbulent model is utilized. The CFD method is firstly validated using existing experimental data. Then the influences of plate length and system damping on the performance of the FIVEC are evaluated. The results show that the device has a maximum averaged power coefficient of 0.0520 (13.86 W) in the considered situations. The results also demonstrate the feasibility of this energy converter plan.

Design and realization of a novel magnetic nutation drive for industry robotic wrist reducer

PurposeThe purpose of this research is to achieve a novel magnetic nutation drive for an industry robotic wrist reducer.Design/methodology/approachA novel magnetic nutation drive is proposed, and the structure and principle of the designed magnetic nutation drive are described in this study. Three-dimensional finite element analysis is used to compute the magnetic and torque of the magnetic nutation drive. Furthermore, a prototype of this novel magnetic nutation drive device is developed with 3D printing technology and tested to verify the feasibility of the proposed structure and principle.FindingsThe simulation and experimental results indicated that the proposed magnetic nutation drive device could meet the desired specifications, and that this novel magnetic nutation drive device successfully realized the non-contact transmission ratio of 105:1 required for a robotic wrist reducer.Practical implicationsThis novel magnetic nutation drive is low-cost and easy to make and use, and which provides the non-contact transmission ratio of 105:1 required for a robotic wrist reducer.Originality/valueFor the first time, this research applies the permanent magnet drive technology to nutation drive and puts forward a new non-contact nutation drive mode. The novel drive mode can solve some problems of the traditional mechanical contact nutation drive, such as vibration, friction loss, mechanical fatigue and necessity of lubrication. The proposed non-contact nutation drive device can achieve a high reduction ratio with compact structure and can be suitable for industry application.

螺旋型磁石を用いない磁気ねじアクチュエータの提案

This paper presents a novel magnetic lead screw actuator without helical permanent magnets. Magnetic lead screw actuator is high efficiency due to its non-contact transmission. It is expected to be applicable to interactive robots with human because of its compliance to external forces. The proposed actuator has simple structure comparing to the conventional magnetic screws. The result of the force calculation and structure optimization employing 3-D finite element method is reported.

The Transfer efficiency analysis and modeling technology of new non - contact power transmission equipment

Due to the shortcomings of current power transmission which is used in ultrasound - assisted machining and the different transfer efficiency caused by the related parameters of the electromagnetic converter, this paper proposes an analysis model of the new non-contact power transmission device with more stable output and higher transmission efficiency. Then By utilizing Maxwell finite element analysis software, this paper studies the law of the transfer efficiency of the new non-contact transformer and compares new type with traditional type with the method of setting the boundary conditions of non-contact power supply device. At last, combining with the practical application, the relevant requirements which have a certain reference value in the application are put forward in the actual processing.

Research and Realization of a Medium Power Wireless Power Transmission System

In order to solve the inconvenience of pluggable power transmission, this paper attempts to design a non-contact transmission energy system.In this paper, the system device is divided into transmitter and receiver, and the study designed a special mechanical structure to solve the problem of coil offset. The computer simulation and practical experiments get the transmitting and receiving coils at different distances in the transmission power and efficiency, and the optimal transmission distance between the transmitting and receiving coils is obtained. Through a large number of related experiments done in the air, the experimental results further validate the accuracy of the simulation theory. When the inverter input voltage is 100V and the system frequency is 98.7kHz, the system transmission power up to 613W, which can provide a scientific theoretical basis and reference for further underwater wireless power transmission experiment.