Small Motors Research Articles

2P1-D06 タンデム型マルチモータパワーユニットの開発(アクチュエータの機構と制御(3))

In recent years, many electrically powered vehicles are developed and produced on the whole world. Most of these products are driven by a single large electric motor. A high power motor has problems such as large inertia and low maximum speed. These problems make the motor difficult to achieve the equivalent power characteristics of a gasoline engines. In this study, we had developed and improved a power unit which consists of many small DC motors. We had developed the Unit Type Multi-motor Power Unit that connects each unit with low power motors. Experiments will be done to analyze the performance of the Unit Type Multi-motor Power Unit and to identify its merits and demerits.

1A2-E05 隠れ振動知覚を利用したテクスチャ提示(ハプティックインタフェース(2))

In this paper, we propose a texture display using phenomenon named hidden vibration perception. This was found in an investigation of haptic feelings with vibrating plate. Hidden vibration perception is a tactile perception that when drag a plane through a thin plate with vibrator, although the vibrator is running, we feel the vibration only when we drag. Thus we can feel the vibration of the plate as if it is a texture between the plate and the plane. We also propose a display using our method and examine the possibility of method by developing a prototype. The prototype consists of a thin polypropylene plate small eccentric motors attatched and a tablet PC.

A New Method for Rapid Surface Modeling (RSM)

The rapid surface Modeling (RSM) method represents a new type of 3-D computer modeling device for surface shape using a pin-rod matrix. The prototype RSM system containing a 4*4 array of pin-rods is designed and implemented. Thanks to long movement range, it is capable of displaying large-scale objects. This device consists of arrays of electrically actuated cells under the control of small stepper motors. After designing desired model in the range of our prototype matrix in a CAD software, its model is meshed in 4*4 matrix corresponding to the size of 4*4 RSM prototype. Then every single mesh 3-D coordinate is specified and according to this data its respective rod is individually moved up by their actuators controlled using a CAM software to form the desired model. Since in this system, all the actuators can be activated at the same time, preparation process of modeling is so fast and precise in compared with other similar methods proposed in the past.

The Design of Performance Testing System for Small Motors

This paper provides an overview of the sort of motor’s losses, analyzes and expatiates on several methods of testing for efficiency, designs a set of scheme for motor energy efficiency testing. The test platform can achieve the aim of resistance measurement, temperature measurement, power analysis and data processing and other test. The system can further improve the authentication level of the motor, system testing results can provide the basis for the relevant departments of the state. Practical application shows that the detection result of this system is reliable and accurate.

Advanced Materials Application in Flat Television Steering Bracket

This paper mainly talks about the problem of flat television’s placement and the creative design of this automatic steering bracket which designed on the basis of analyzing the existing brackets and aims to make televisions turning around instantly, conveniently and automatically (instead of never moved or hand operated) for people who are watching TV from whichever angle. It is the working of two small electrical motors drives the rotation of the rack at horizontal direction and vertical direction. And only with the help of its remote control can this automatic steering bracket divert the television. The bracket was made of bigger strength aluminum alloy, it is lighter weight, stainless, surface beautiful, compared with traditional processing methods, and selecting aluminum alloy can remarkably improve the production efficiency, ensure product quality and improve the qualification rate of finished products.

ChemInform Abstract: Current Status and Recent Topics of Rare‐Earth Permanent Magnets

AbstractReview: 80 refs.

Induction Motors Performance Study under Various Voltage Sags Using Simulation

The main aim of this paper is to study effects of different voltage sags and their intensity on the behavior of induction motors using a simulation approach. For this purpose, necessary simulation was done in Matlab - Simulink first. Then, to ensure-reasonable accuracy of the simulation, some results of the simulation were compared with the corresponding results measured in the laboratory. Then effects of intensity of symmetric voltage sag (three phase) and its starting point on the behavior of small and large induction motors was studied using simulation and subsequently, the effects of asymmetric voltage sags (single phase and two phase) has also been studied and finally the conclusion of the study was presented.

Automatic Inspection System for Electric Motors with Integrated Bus Interface

This paper describes an automatic test system for small power electric motors with integrated intelligent control unit. The testing concept utilizes the sensors integrated in the motor and the communication capabilities of the drive. Therefore, the motors can be tested quickly, yet thoroughly during manufacturing without the need for cost intensive test stands.

Correlation analysis of brush temperature in brush-type DC motor for predicting motor life

Some critical components of motors and generators have sliding electrical contacts. Electrical brushes are usually used in these contact points to conduct current between the stationary part and the moving part of the motor. In this paper, studies on brush wear against copper commutators are briefly reviewed. The main influential factors in brush wear are associated with both mechanical wear and electrical wear. Brush wear is affected by various factors, including temperature, material properties, sliding speed, contact force, and interfacial as well as environmental conditions. The mechanical wear of brushes is proportional to brush spring pressure and sliding speed, and the electrical wear of brushes is associated with current and contact voltage drop. For characterization, a brush wear test machine is designed, and influential factors, such as electrical contact resistance, temperature, wear mass loss, and so on, are measured. The wear tests are processed using a small brush-type automotive DC motor. The study primarily aims to investigate the effects of the wear behavior of copper-graphite brushes on small brush-typed DC motors. The variable conditions of electrical current are obtained by changing the brush spring pressure and the sliding speed. The results are electrical contact resistance, voltage drop, brush surface temperature rise, and so on. Brush wear is greatly changed by electrical current, which indicates that high current itself not only produces more Joule heating but also causes an increase in voltage drop that will result in additional Joule heating.

희토류 자원분쟁과 NdFeB계 이방성 본드자석 개발동향

지난 5년간 NdFeB계 이방성 본드자석은 25 MGOe의 높은 자기특성을 강점으로 기존 페라이트 영구자석을 갈음하면서 모터의 경량화라는 새로운 패러다임을 주도했고 자동차용과 전동공구용 모터산업분야에서 두드러진 약진을 보였다. 또한 차체중량감소를 통한 연비향상이라는 자동차산업의 기술동향에 정확히 초점을 두고 기존모터의 50 % 경량화라는 새로운 변혁을 이끌어 냈다. 그러나 2010년 7월에 중국이 희토류원소의 수출규제를 발표함에 따라 2011년 희토류 원자재는 또 한 차례의 폭등을 기록하였고 그 여파는 전방 수요산업에 심각한 충격으로 던져지고 있다. 각 희토류 주요 소비국들은 자원 확보, 희토류 최소사용부품개발 및 희토류 대체 신기술개발 강화에 총력을 다하는 모습이다. 이러한 환경적 변화가 이방성 본드자석 분야에는 중희토류 원소인 Dy의 사용량을 줄이면서 보자력을 향상시키고자하는 기술적 도전을 유발하였고 모터고속화 응용분야에 탐색을 시도하게 하였다. 본 글에서는 희토류 자원문제에 대한 각국 희토류자석산업의 대응과 NdFeB 이방성 본드자석으로 대표되는 Aichi Steel사의 MAGFINE 자성분말에 대해 최근의 개발 동향 및 응용분야에 대해 소개하고자 한다. NeFeB anisotropy bonded magnet has proposed a new paradigm of weight reduction of small motors by replacing the conventional ferrite permanent magnets with its high magnetic property of 25 MGOe during last five years. It has also advanced by leaps and bounds in the field of motor industry for automobiles and electric power tools. And it has led a new innovation of fifty percent weight lightening compared to its current motors by correctly focusing on fuel performance improvement through weight lightening that automobile industry chased. There was, however, another price skyrocketing in 2011 after China had announced its export regulation in rare earth materials in July, 2010. And this price change has an extensive impact on the industries that consume rare earth magnets. This environmental change has caused technical challenge to improve the performance by using least amount of rare earth elements in NdFeB anisotropy bonded magnets, and led to make a new technical approach to a new applied field. In this article, we will show how each nation deals with this industrial issue, and introduce development trend and application of anisotropic NdFeB bonded magnets, so-called MAGFINE made by Aichi Steel Corp.

A fast mesoscale quadruped robot using piezocomposite actuators

SUMMARYThis paper introduces the design, analysis, and experimental results of a fast mesoscale (12 cm length) quadruped mobile robot that employs unconventional actuators. Four legs of the robot are actuated by two pieces of piezocomposite actuator named LIPCA, which enables the robot to achieve the bounding gait with only one degree of freedom per leg. The forward locomotion is obtained by a creative idea in the design and the speed can be controlled by changing the frequency of actuators. The mechanism of power transfer has been improved in order to use the actuation power more efficiently. Two small RC-servo motors are added to control the locomotion direction. In addition, a small power supply and control circuit is developed that is fit for the robot. Our experiments show that the robot can locomote as fast as about two times its body length per second with the circuit board and a battery installed. The robot is also able to change the heading direction in a controlled way and is capable of continuous operation for 35 min.

Advances on Single-Phase Line-Start High Efficiency Interior Permanent Magnet Motors

The past 25 years have been a significant period with advances in the development of interior permanent magnet (IPM) machines. Line-start small IPM synchronous motors have expanded their presence in the domestic marketplace from few specialized niche markets in high efficiency machine tools, household appliances, small utility motors, and servo drives to mass-produced applications. A closer examination reveals that several different knowledge-based technological advancements and market forces as well as consumer demand for high efficiency requirements have combined, sometimes in fortuitous ways, to accelerate the development of the improved new small energy efficient motors. This paper provides a broad explanation of the various factors that lead to the current state of the art of the single-phase interior permanent motor drive technology. A unified analysis of single-phase IPM motor that permits the determination of the steady-state, dynamic, and transient performances is presented. The mathematical model is based on both d-q axis theory and finite-element analysis. It leads to more accurate numerical results and meets the engineering requirements more satisfactorily than any other methods. Finally, some concluding comments and remarks are provided for efficiency improvement, manufacturing, and future research trends of line-start energy efficient permanent magnet synchronous motors.

Design of a Compact and Multi-Function Magnetic Field Steered Arc Source

Based on the principle of the control of magnetic field on arc spot motion, a compact and multi-function magnetic field steered arc source has been designed in this paper. The rotating magnetic field generator driven by small DC motors or AC motors has been also equipped behind the base of the target materials of magnetic field steered arc source. The magnet yoke fixed on shaft will be driven by the motors so as to promote the rotation of permanent magnets which are rationally distributed on magnet yoke. The different distribution of permanent magnets will produce the rotating magnetic field with different configuration structures and then the purpose of multi-control mode can be achieved. Meanwhile, the dynamic rotating magnetic field with different configurations have been also produced in this design through employing the simple and compact arc source as well as the permanent magnet with different distributions in order to improve the discharge form of arc spots, control the trajectory of arc spots, improve the utilization of target materials and the uniformity of etching as well as reduce or inhibit the emission of large particles. At the same time, the high-quality film can be also prepared so as to realize the arc spot control with various forms in an arc source, satisfy the different demands and expand the application of arc ion plating.

영구자석형 다자유도 구형전동기의 토크특성 분석과 효율 향상에 대한 연구

A surfaced permanent magnet spherical motor is capable of operating as three degree of freedom that used for the joints of the robot"s arm, leg, and eyes. Ongoing research like new concept is essential part of motor field, it will make a great contribution in the future the overall portion of the motor, is becoming expected. The author analysis torque characteristics in spherical motor with state of rotating and positioning. And future design direction is smaller motors with equivalent or higher output. Solutions as torque and efficiency improvements are selecting the core with special processing type like powder metallurgy materials. Their special characteristic is high permeability and low eddy current losses at high speed, so improved the torque and efficiency.

DyフリーNd-Fe-B系異方性ボンド磁石の開発と小型モータへの応用

The authors have successfully developed a low-cost anisotropic Nd-Fe-B magnet powder with a high coercivity value of 1591 kAm−1 without any dysprosium additives by diffusion processing of Nd-Cu-Al element into anisotropic magnet powder produced by the d-HDDR (dynamic-hydrogenation, disproportionation, desorption and recombination) method. This enhancement mechanism is to isolate the magnetic coupling between the grains of Nd2Fe14B phase by a Nd rich grain boundary phase with Cu. By surface coating this anisotropic magnet powder, the long-term aging loss behavior under air at 150℃ is less than 5% after 1000 h. By using this new anisotropic bonded magnet (New-MAGFINE), small automotive motors with excellent thermal stability and low cost characteristics have become possible.

More motor, less power [electric motors

Better control over component-level electric motors could yield massive energy savings, and a two-pronged attack is yielding results across a range of products. Improvements to efficiency standards for small electric motors could easily outweigh the energy consumption reductions in computers and their displays from now until the end of 2035, according to a report published earlier this year by the American Council for an Energy-Efficient Economy (ACEEE). What's more, this does not include the motors built into other equipment, such as air conditioners and washing machines.

Small Machines in the Garden: Everyday technology and revolution in the Mekong Delta

AbstractTwentieth-century industrialization in the agricultural landscapes of the Mekong Delta in Vietnam took a very different form from other places, characterized less by a continuous spread of large-scale technology than by its destruction in mid-century and the subsequent spread of small technology which powered scooters, water pumps, and boats. The numbers of these portable motors, an everyday technology in 1960, rose from a few thousand units in 1963 to millions in the present day. The colonial and post-colonial state in Vietnam played a key role in the demise of large technology and, ultimately, of the water infrastructure. Its failures during wartime spurred farmers to adopt cheap, small engines to survive; however, the state's role was complex during this time. Several key factors, including the influence of American aid programmes and the contributions of Taiwanese agricultural advisers, especially those pushing high-yield rice, favoured the adoption of small engines. From an ecological viewpoint, the post-1960 explosion in the use of small motors, especially as water pumps, has brought people and states in Southeast Asia to an ecological impasse as unrestricted use has impacted on water tables, salinity levels, and the long-term sustainability of agriculture in many places. This paper examines the state's indirect role in shaping this silent revolution, and it considers the political and ideological factors underpinning its history.

Magnet makeover

In ancient times, they were considered magical objects with supernatural powers. These days, we just stick them on our refrigerators. Yet those little magnets deserve our admiration more than ever. Take laptop computers, with their slim hard drives. It became possible to manufacture the motors for those drives only after the development of especially powerful permanent magnets in the early 1980s. Such muscular magnets are now found in many other places as well-various household appliances, cellphones, and the small electric motors that operate accessories in our cars, to name a few. They are also critical in the brawny electric motors that propel hybrid vehicles and in the generators attached to many wind turbines. So they can help both to reduce energy consumption and produce green electric power. Because the magnets themselves are hidden away, many of us tend to take them for granted. We shouldn't, especially not now. The manufacture of most high-performance magnets requires neodymium, a rare earth element that's in short supply. Almost all of the world's production comes from China, which has increasingly restricted exports to ensure that it has enough to satisfy its own needs. So the price of neodymium has been skyrocketing. If the trend continues, pretty soon we'll have a real crisis on our hands.

From High-Tech to Biotech Using Stem Cell and Gene Therapy to Treat Hearing Loss

From High-Tech to Biotech Using Stem Cell and Gene Therapy to Treat Hearing Loss

DLP용 유체동압베어링 스핀들모터

The small precision spindle motors in the high value-added products including the visible home appliances such as DLP projector require not only the energy conversion devices but also high efficiency, low vibration and sound operation. However, the spindle motors using the conventional ball bearing and sintered porous metal bearing have following problems, respectively: the vibration by the irregularity of balls and the short motor life cycle by the ball's abrasion and higher sound noises by dry contact between shaft and sleeve. In this paper, it is proposed that the spindle motor with a fluid dynamic bearing is suitable for the motor to drive the color wheel of the DLP(digital lightening processor) in the visible home appliances. The proposed spindle motor is composed of the fluid dynamic bearing with both the radial force and the thrust force. The fluid dynamic bearing is solved by the finite element analysis of the mechanical field with the Reynolds equations. The magnetic part of spindle motor, which is a type of Brushless DC Motor, is designed by the electro-magnetic field analysis coupled with the Maxwell equation. And the load capacity and the friction loss of fluid dynamic bearing are analyzed to bearing clearance variation by the fabrication error in designed motor. The design of the proposed motor is implemented by the load torque caused by the eccentricity and the unbalance of the fluid dynamic bearing when the motors are fabricated in error. The prototype of the motor with the fluid dynamic bearing is manufactured, and experiment results show the vibration, sound, and phase current at no load and color wheel load of the motors in comparison. The high performance characteristics with the low vibration, the low acoustic noise and the optimal mechanical structure are verified by the experimental results.