scholarly journals Motor Using Mechanical Vibration of Multiple Bimorph Beams

2017 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Hiroyuki Yaguchi
Keyword(s):  
Rotational Speed ◽  
Electrostatic Force ◽  
Mechanical Vibration ◽  
Resonance Energy ◽  
Input Voltage ◽  
Input Power ◽  
Maximum Efficiency ◽  
Cantilever Beams ◽  
Flexible Material ◽  
Output Torque

The present paper proposes a non-magnetic motor with a rotor rotated by the mechanical resonance energy of four bimorph cantilever beams excited by an electrostatic force. The use of a flexible material such as silicon rubber enables conversion of translational vibration to rotary movement in one direction. The rotational speed of the proposed motor increases in proportion to the input voltage when two bimorph beams are used, and the maximum rotational speed was found to be 6,804 rpm when the input voltage was set to 24.6 V. Next, the basic characteristics of a prototype motor with four bimorph cantilever beams, including rotational speed, output torque, and efficiency, were determined experimentally. The experimental results revealed that a maximum rotational speed of 6,370 rpm was obtained when the output torque was 19.6 uNm. The proposed motor was also observed to produce an output torque of 63.7 uNm when the rotational speed was 1,491 rpm. The maximum efficiency was 6.2% when the input power was 0.3 W. For the proposed motor, the volume and weight were reduced by approximately 35%, as compared with a motor from a previous study.

scholarly journals Maximizing Transfer Efficiency with an Adaptive Wireless Power Transfer System for Variable Load Applications

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1417
Author(s):  
Jung-Hoon Cho ◽  
Byoung-Hee Lee ◽  
Young-Joon Kim
Keyword(s):  
Loading Condition ◽  
Wireless Power Transfer ◽  
Input Voltage ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Variable Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Variable Loading ◽  
Power Transfer Efficiency

Electronic devices usually operate in a variable loading condition and the power transfer efficiency of the accompanying wireless power transfer (WPT) method should be optimizable to a variable load. In this paper, a reconfigurable WPT technique is introduced to maximize power transfer efficiency in a weakly coupled, variable load wireless power transfer application. A series-series two-coil wireless power network with resonators at a frequency of 150 kHz is presented and, under a variable loading condition, a shunt capacitor element is added to compensate for a maximum efficiency state. The series capacitance element of the secondary resonator is tuned to form a resonance at 150 kHz for maximum power transfer. All the capacitive elements for the secondary resonators are equipped with reconfigurability. Regardless of the load resistance, this proposed approach is able to achieve maximum efficiency with constant power delivery and the power present at the load is only dependent on the input voltage at a fixed operating frequency. A comprehensive circuit model, calculation and experiment is presented to show that optimized power transfer efficiency can be met. A 50 W WPT demonstration is established to verify the effectiveness of this proposed approach.

scholarly journals Research on aerodynamic characteristics of two-stage axial micro air turbine spindle for small parts machining

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098437
Author(s):  
Liu Jiang ◽  
Guo Zhiping ◽  
Miao Shujing ◽  
He Xiangxin ◽  
Zhu Xinyu
Keyword(s):  
High Speed ◽  
Aerodynamic Characteristics ◽  
Maximum Efficiency ◽  
Two Stage ◽  
Output Torque ◽  
Air Turbine ◽  
Solid Foundation ◽  
Computational Fluid Dynamics Cfd ◽  
Micro Machine ◽  
Small Parts

In order to meet the requirements of output torque, efficiency and compact shape of micro-spindles for small parts machining, a two-stage axial micro air turbine spindle with an axial inlet and outlet is proposed. Based on the k-ω turbulence model of SST, the flow field and operation characteristics of the two-stage axial micro air turbine spindle were studied using computational fluid dynamics (CFD) combined with an experimental study. We obtained the air turbine spindle under different working conditions of the loss and torque characteristics. When the inlet pressure was 300 KPa, the output speed of the two-stage turbine was 100,000 rpm, 9% higher than that of a single-stage turbine output torque. The total torque reached 6.39 N·mm, and the maximum efficiency of the turbine and the spindle were 42.2% and 32.3%, respectively. Through the research on the innovative structure of the two-stage axial micro air turbine spindle, the overall performance of the principle prototype has been significantly improved and the problems of insufficient output torque and low working efficiency in high-speed micro-machining can be solved practically, which laid a solid foundation for improving the machining efficiency of small parts and reducing the size of micro machine tool.

Experimental Characterization of a Flexible Two-Link Manipulator Arm

1993 ◽  
Author(s):  
Randall L. Mayes ◽  
G. Richard Eisler
Keyword(s):  
Element Model ◽  
Input Voltage ◽  
Analytical Models ◽  
Experimental Characterization ◽  
Frequency Range ◽  
Flexible Links ◽  
Beam Elements ◽  
Output Torque ◽  
Manipulator Arm

Abstract Experiments were performed to verify the analytical models for a robotic manipulator with two flexible links. A finite element model (FEM) employing two-dimensional beam elements was used to model the structure. A proportional model relating input voltage to output torque was used for both hub and elbow joint motors. With some minor adjustments to the link stiffness, the FEM modal frequencies matched the experimentally extracted frequencies within 1.5%. However the voltage-torque relationship for the hub motor was found to exhibit dynamics in the frequency range of interest.

A methodology for loss and performance assessment of a variable geometry turbocharger turbine through a new meanline FORTRAN program

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ahmed Ketata ◽  
Zied Driss
Keyword(s):  
Rotational Speed ◽  
Internal Combustion Engines ◽  
Maximum Efficiency ◽  
Variable Geometry ◽  
Mixed Flow ◽  
Content Type ◽  
Variable Geometry Turbocharger ◽  
Nozzle Vane ◽  
Wide Range ◽  
Vane Angle

PurposeVariable geometry turbine (VGT), a key component of modern internal combustion engines (ICE) turbochargers, is increasingly used for better efficiency and reduced exhaust gas emissions. The aim of this study is the development of a new meanline FORTRAN code for accurate performance and loss assessment of VGTs under a wider operating range. This code is a useful alternative tool for engineers for fast design of VGT systems where higher efficiency and minimum loss are being required.Design/methodology/approachThe proposed meanline code was applied to a variable geometry mixed flow turbine at different nozzle vane angles and under a wide range of rotational speed and the expansion ratio. The numerical methodology was validated through a comparison of the predicted performance to test data. The maps of the mass flow rate as well as the efficiency of the VGT system are discussed for different nozzle vane angles under a wide range of rotational speed. Based on the developed model, a breakdown loss analysis was carried out showing a significant effect of the nozzle vane angle on the loss distribution.FindingsResults indicated that the nozzle angle of 70° has led to the maximum efficiency compared to the other investigated nozzle vane angles ranging from 30° up to 80°. The results showed that the passage loss was significantly reduced as the nozzle vane angle increases from 30° up to 70°.Originality/valueThis paper outlines a new meanline approach for variable geometry turbocharger turbines. The developed code presents the novelty of including the effect of the vane radii variation, due to the pivoting mechanism of the nozzle ring. The developed code can be generalized to either radial or mixed flow turbines with or without a VGT system.

Carbon Fiber Based Twisted and Coiled Artificial Muscles (TCAMs) for Powered Ankle-Foot Orthoses (AFO)

2021 ◽  
Author(s):  
Parth Kotak ◽  
Jason Wilken ◽  
Kirsten Anderson ◽  
Caterina Lamuta
Keyword(s):  
Carbon Fiber ◽  
Low Cost ◽  
Input Voltage ◽  
Input Power ◽  
Artificial Muscles ◽  
Specific Work ◽  
Foot Orthoses ◽  
Ankle Foot Orthoses ◽  
Low Cost Manufacturing

Abstract Ankle foot orthoses (AFOs) control the position and motion of the ankle, compensate for weakness, and correct deformities. AFOs can be classified as passive or powered. Powered AFOs overcome the limitations of passive AFOs by adapting their performance to meet a variety of requirements. However, the actuators currently used to power AFOs are typically heavy, bulky, expensive, or limited to laboratory settings. Thus, there is a strong need for lightweight, inexpensive, and flexible actuators for powering AFOs. In this technical brief, Carbon Fiber/Silicone Rubber (CF/SR) Twisted and Coiled Artificial Muscles (TCAMs) are proposed as novel actuators for powered AFOs. CF/SR TCAMs can lift up to 12,600 times their weight with an input power of only 0.025 W cm-1 and are fabricated from inexpensive materials through a low-cost manufacturing process. Additionally, they can provide a specific work of 758 J kg-1 when an input voltage of 1.64 V cm-1 is applied. A mechanical characterization of CF/SR TCAMs in terms of length/tension, tension/velocity, and active-passive length/tension is presented, and results are compared with the performance of skeletal muscles. A gait analysis demonstrates that CF/SR TCAMs can provide the performance required to supplement lower limb musculature and replicate the gait cycle of a healthy subject. Therefore, the preliminary results provided in this brief are a stepping stone for a dynamic AFO powered by CF/SR TCAMs.

scholarly journals Design Method of Double-Boost DC/DC Converter with High Voltage Gain for Electric Vehicles

2020 ◽  
Vol 11 (4) ◽  
pp. 64 ◽  
Author(s):  
Zhengxin Liu ◽  
Jiuyu Du ◽  
Boyang Yu
Keyword(s):  
Electric Vehicles ◽  
High Voltage ◽  
Direct Current ◽  
Output Voltage ◽  
Input Voltage ◽  
Maximum Efficiency ◽  
Voltage Gain ◽  
Current Feedback ◽  
Voltage Ripple ◽  
High Voltage Gain

Direct current to direct current (DC/DC) converters are required to have higher voltage gains in some applications for electric vehicles, high-voltage level charging systems and fuel cell electric vehicles. Therefore, it is greatly important to carry out research on high voltage gain DC/DC converters. To improve the efficiency of high voltage gain DC/DC converters and solve the problems of output voltage ripple and robustness, this paper proposes a double-boost DC/DC converter. Based on the small-signal model of the proposed converter, a double closed-loop controller with voltage–current feedback and input voltage feedforward is designed. The experimental results show that the maximum efficiency of the proposed converter exceeds 95%, and the output voltage ripple factor is 0.01. Compared with the traditional boost converter and multi-phase interleaved DC/DC converter, the proposed topology has certain advantages in terms of voltage gain, device stress, number of devices, and application of control algorithms.

Fabrication of Nano-Electromechanical Structures Down to 20 nm by Spacer Technology

2007 ◽  
Author(s):  
Xiang Han ◽  
Ling Xia ◽  
Wengang Wu ◽  
Guizhen Yan ◽  
Jun Xu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Mechanical Vibration ◽  
Cantilever Beams ◽  
Fabrication Method ◽  
Feature Size ◽  
Plasma Damage ◽  
Nano Fabrication ◽  
Nano Structures ◽  
20 Nm ◽  
Deposited Film

Spacer technology has been developed to fabricate nano-structures for NEMS application. It provides a parallel nano-fabrication method with double or quadplex device density at a certain lithography node. By controlling the deposited film thickness, the feature size of the SiO2 spacer hard mask is reduced down to 35 nm. After the spacer pattern is transferred to Si, a precise thermal oxidation is performed to improve the profile and reduce the plasma damage. Finally, sublimation or HF vapor phase etching is introduced to release the nano-structures according to different structure dimensions. As a result, with better surface morphology, suspended Si nano-beams with a width of 20 nm are obtained. Actuated by mechanical vibration and electrostatic forces, vibrations of the obtained cantilever beams and fixed-fixed beams are observed in SEM. In addition, a metallic nano-nozzle with a diameter of 140 nm is established by electroless plating around the suspended Si nano-beam served as a mold. As a development of the spacer technology, nano-needle array is demonstrated at the cross points of crossed SiO2 spacers by anisotropic etching. The diameters of the hybridized nano-needles are 300 nm so far and can be further reduced by smaller spacer dimension.

SENSOR-LESS ESTIMATION OF PRESSURE HEAD AND FLOW OF A CONTINUOUS-FLOW ARTIFICIAL HEART BASED ON INPUT POWER AND ROTATIONAL SPEED

ASAIO Journal ◽  
2000 ◽  
Vol 46 (2) ◽  
pp. 188 ◽  
Author(s):  
M. Yoshizawa ◽  
T. Sato ◽  
A. Tanaka ◽  
K. Abe ◽  
T. Yambe ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Continuous Flow ◽  
Artificial Heart ◽  
Pressure Head ◽  
Input Power

Research on Overloading Protection of Permanent Magnetic Coupler in Coal Mine

2014 ◽  
Vol 597 ◽  
pp. 492-497
Author(s):  
Wen Qi Yuan ◽  
Yue Liu ◽  
Dong Li ◽  
Guo Ying Meng
Keyword(s):  
Experimental Data ◽  
Mechanical Characteristic ◽  
Coal Mine ◽  
Mechanical Characteristics ◽  
Input Power ◽  
Maximum Torque ◽  
Characteristic Curves ◽  
Motor Torque ◽  
Output Torque

In this paper, with simulations and experiments analysed by the software of Ansoft Maxwell, research on overloading protection of permanent magnetic coupler in coal mine is carried out and the conclusive curves of mechanical characteristics are plotted through experimental data. The conclusion can be gained from mechanical characteristic curves: when the output value of torque reaches the maximum torque of magnetic coupler, the output torque and speed will drop along with increases of the slip, and the input power value of motor is less than the power value at the time when the motor torque value is at the maximum. It explains that the magnetic coupler has the function for overloading protection.

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