A life test of ultrasonic motors under different torque loads and the analysis of the characteristics of wearing surfaces

2019 ◽  
Vol 234 (5) ◽  
pp. 770-777
Author(s):  
Liwei Zhang ◽  
Huiming Zheng ◽  
Shouqing Huang ◽  
Wu Zhang ◽  
Fangyong Li ◽  
...  
Keyword(s):  
Early Time ◽  
Life Time ◽  
High Energy ◽  
Friction Material ◽  
Ultrasonic Motor ◽  
High Energy Density ◽  
Life Test ◽  
Wear Process ◽  
Ultrasonic Motors ◽  
Start Up

Without a coil and a gearbox, an ultrasonic motor has an important application in space engineering and so forth with advantages of light weight, small volume, less electromagnetic radiation, fast dynamic response, and high energy density. However, the obvious friction and wear between the stator and the friction material (as a part of the shaft assembly) restrict the reliability and life time of the ultrasonic motor. In this paper, a life test of ultrasonic motors is designed and carried out for 3041.7 h, and the eight motors are divided into four groups with torque loads of 0.03 Nm, 0.09 Nm, 0.16 Nm, and 0.21 Nm in the test. The evolution characteristics of the displacement frequency response and the wear on the stator contact surface under different torque loads during the wear process are analyzed. Some start-up problems occur during the early time in the life test are found and explained based on a meshing effect between the stator and the friction material, and some targeted suggestions are proposed to overcome the problems. The study can help to understand the wear failure mechanism and characteristics of ultrasonic motors.

scholarly journals Single Vibration Mode Standing Wave Tubular Piezoelectric Ultrasonic Motor

2021 ◽  
Author(s):  
Soonho Park
Keyword(s):  
Standing Wave ◽  
Vibration Mode ◽  
Cylindrical Tube ◽  
Electrical Energy ◽  
High Energy ◽  
High Energy Density ◽  
Ultrasonic Frequency ◽  
Ultrasonic Motors ◽  
Piezoelectric Motors ◽  
Piezoelectric Effects

The objective of this thesis is to report the single vibration mode standing wave tubular piezoelectric ultrasonic motors developed. Piezoelectric motors are driven by reverse piezoelectric effects which converts an input of ultrasonic frequency of electrical energy into an output of mechanical movement. There are many advantages of piezoelectric ultrasonic motors compared to electromagnetic motors such as simple structure, high energy density, and high torque at low speed. Three prototypes are designed and fabricated. Two motors are fabricated using PZT cylindrical tube; one with PZT teeth and the other with metal teeth. A third motor using brass tube with PZT plates attached is fabricated. After design and fabrication of three prototypes, the performances of the motors are tested using a test apparatus for speed and torque.

High End Battery Management Systems for Renewable Energy and EV Applications

Green ◽  
2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Max Jung ◽  
Simon Schwunk
Keyword(s):  
Lithium Ion ◽  
Life Time ◽  
High Energy ◽  
High Energy Density ◽  
Management Systems ◽  
Battery Management ◽  
Wind Generators ◽  
Battery Management Systems ◽  
Battery Systems ◽  
Battery Packs

AbstractUsing renewable energies means having to deal with a strongly stochastic behaviour, since for photovoltaics the sun has to shine or for wind generators the wind has to blow. For being able to supply the load any time, storage solutions are needed. Decreasing costs and better availabilities of new battery technologies like lithium-ion therefore result in a growing demand for more sophisticated battery systems in off-grid and grid connected applications. In e.g. off-grid applications, lead-acid battery systems are state of the art. Though, lithium-ion batteries become more popular because of their high energy density and long life time. Another application for electrochemical storage systems are electric vehicles. In all those cases the battery storages need to be managed. But the management of a battery system is not a trivial problem. The batteries must be monitored and controlled, there are challenges regarding safety, electrical isolation and energy efficiency. The article gives an introduction to different architectures of battery management systems (BMS). There are different approaches to design a BMS the article describes in the first part. In the second part, there is a more precise description of the electronic hardware and the software behind a BMS. To understand both function and importance of a BMS, the article introduces in the third part a few applications of BMS in bigger battery packs.

scholarly journals Single Vibration Mode Standing Wave Tubular Piezoelectric Ultrasonic Motor

2021 ◽  
Author(s):  
Soonho Park
Keyword(s):  
Standing Wave ◽  
Vibration Mode ◽  
Cylindrical Tube ◽  
Electrical Energy ◽  
High Energy ◽  
High Energy Density ◽  
Ultrasonic Frequency ◽  
Ultrasonic Motors ◽  
Piezoelectric Motors ◽  
Piezoelectric Effects

The objective of this thesis is to report the single vibration mode standing wave tubular piezoelectric ultrasonic motors developed. Piezoelectric motors are driven by reverse piezoelectric effects which converts an input of ultrasonic frequency of electrical energy into an output of mechanical movement. There are many advantages of piezoelectric ultrasonic motors compared to electromagnetic motors such as simple structure, high energy density, and high torque at low speed. Three prototypes are designed and fabricated. Two motors are fabricated using PZT cylindrical tube; one with PZT teeth and the other with metal teeth. A third motor using brass tube with PZT plates attached is fabricated. After design and fabrication of three prototypes, the performances of the motors are tested using a test apparatus for speed and torque.

Pilot-scale combustion studies with kraft lignin in a powder burner and a CFB boiler

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND
Keyword(s):  
Circulating Fluidized Bed ◽  
Black Liquor ◽  
Chloride Content ◽  
Pilot Scale ◽  
High Energy ◽  
Kraft Lignin ◽  
High Energy Density ◽  
Alkali Chloride ◽  
Cfb Boiler ◽  
Solid Biofuel

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.

A HIGH ENERGY DENSITY ZINC/OXYGEN BATTERY SYSTEM

1966 ◽  
Author(s):  
S. CHODOSH ◽  
E. KATSOULIS ◽  
M. ROSANSKY
Keyword(s):  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Battery System

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Potassium Pre-Inserted K1.04Mn8O16 Cathode Materials for Aqueous Li-Ion and Na-Ion Hybrid Capacitors

2019 ◽  
Author(s):  
Yamin Zhang ◽  
Lina Chen ◽  
Chongyang Hao ◽  
Xiaowen Zheng ◽  
Yixuan Guo ◽  
...  
Keyword(s):  
Cycling Performance ◽  
High Energy ◽  
High Energy Density ◽  
Potassium Ions ◽  
Tunnel Structure ◽  
Hybrid Supercapacitor ◽  
Hybrid Supercapacitors ◽  
Li Ion ◽  
Power Densities ◽  
Hybrid Capacitors

For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors, potassium ions are pre-inserted into MnO<sub>2</sub> tunnel structure, the as-prepared K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16</sub> materials consist of <a>nanoparticles</a> and nanorods were prepared by facile high-temperature solid-state reaction. <a></a>The as-prepared materials were well studied andthey show outstanding electrochemical behavior. We assembled hybrid supercapacitors with commercial activated carbon (YEC-8A) as anode and K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16 </sub>as cathode. It has high energy densities and power densities. Li-ion capacitors reach a high energy density of 127.61 Wh kg<sup>-1 </sup>at the power density of 99.86 W kg<sup>-1</sup> and Na-ion capacitor obtains 170.96 Wh kg<sup>-1 </sup>at 133.79 W kg<sup>-1</sup>. In addition, the <a>hybrid supercapacitor</a>s demonstrate excellent cycling performance which maintain 97 % capacitance retention for Li-ion capacitor and 85 % for Na-ion capacitor after 10,000 cycles.

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