scholarly journals Development of Low-Frequency Mass Spring System for Underground High-Speed Railways

2021 ◽  
Author(s):  
Shamsul Bashir ◽  
Nasim Akhtar
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Spring System ◽  
Mass Spring

An Analytical Design Methodology for High Speed Nanopositioning Scanners

2015 ◽  
Author(s):  
Vaibhav Sabade ◽  
Tim John Joseph ◽  
V. Kartik
Keyword(s):  
High Speed ◽  
Cross Coupling ◽  
Test System ◽  
Systematic Design ◽  
Analytical Methodology ◽  
One Dimensional ◽  
Parametric Studies ◽  
Spring System ◽  
Manufacturing Tolerances ◽  
Mass Spring

An analytical methodology is presented for the systematic design of a serial kinematic flexure-guided high speed nanopositioning scanner. Approximate relations for the first natural frequency in different directions, achievable range, and in-plane cross-coupling between the axes are obtained considering each stage as a simple one-dimensional mass spring system. Parametric studies are performed to compare these characteristics for a particular range of flexure dimensions. The robustness of the design to manufacturing tolerances, and especially their influence on cross-coupling is investigated. The relations obtained are experimentally verified on a single-axis test system and the measured natural frequencies closely match analytical and FEA predictions. A two-axis nanopositioning system is designed, which has the fast and slow scanning axes’ resonances at 26.36 kHz and 5.28 kHz. The design is validated using finite elements, and the predicted actuation-direction resonances (25.5 kHz and 5.24 kHz respectively) closely agree with those found analytically.

Cableless Magnetic Actuator Capable of High-Speed Movement in Pipe by New Type Propulsion Module

2012 ◽  
Vol 452-453 ◽  
pp. 1252-1256 ◽  
Author(s):  
Tomohiro Izumikawa ◽  
Hiroyuki Yaguchi
Keyword(s):  
High Speed ◽  
Resonance Energy ◽  
Magnetic Actuator ◽  
System A ◽  
New Type ◽  
Spring System ◽  
Inspection And Maintenance ◽  
Mass Spring ◽  
Button Batteries ◽  
Very High

The present paper proposes a novel cableless magnetic actuator that exhibits a very high thrusting force and is capable of high speed locomotion in a thin pipe by using new type propulsion module. The magnetic actuator is moved according to the vibration amplitude and elastic energy of a mass-spring system due to mechanical resonance energy. The proposed actuator contains an electrical inverter that directly transforms DC from button batteries into AC. The electrical DC-AC inverter incorporates a mass-spring system, a reed switch and a curved permanent magnet that switches under an electromagnetic force. Experimental results indicate that the proposed actuator is able to move upward at a speed of 51 mm/s by the power provided by 8 button batteries when pulling a 10 g load mass. This cableless magnetic actuator has several possible applications, including small pipe inspection and maintenance.

Development of a Miniaturized, Electromagnetically Actuated Punch

2015 ◽  
Author(s):  
Markus Ahrens ◽  
Tobias Hasselbusch ◽  
Matthias Dagen ◽  
Bernd-Arno Behrens ◽  
Tobias Ortmaier
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Production Costs ◽  
Test Rig ◽  
Electromagnetic Actuators ◽  
Modular Concept ◽  
Control Concept ◽  
Spring System ◽  
Mass Spring ◽  
Future Work

The production of micro-components in high quantities by means of cutting plays a central role in the area of metal forming. Generally, these components are manufactured with mechanical high speed presses with modified drive kinematics which provide stroke rates of up to 4,000 strokes per minute (spm) and punching forces of up to 2,000 kN. Depending on the application, this may result in a significant oversizing both in terms of maximum cutting force and size of the punching machine. This leads to higher production costs due to increased space and energy consumption which could be improved by a better adaptability of the machine to the process. To fulfill both requirements, a prototype of an electromagnetically driven punch machine with highly efficient resonance drive and miniaturization potential is proposed in this paper. Electromagnetic actuators induce oscillations of a mass-spring system at its resonance frequency by storing potential energy in the system’s springs. An advantage of the resonance propulsion is that only magnets with low nominal force are needed, since only small forces are necessary during the swing-up. The resulting oscillation frequency can be adjusted for the given task by using a modular concept with exchangeable springs. After discussing the concept and essentials, the requirements and constraints are pointed out. Subsequently, a model of the system is created and an energy based bang-bang control concept is implemented utilizing model based filter techniques. Based on the simulation results a test rig was built and obtained measurements were compared to the simulation data. The test rig provides stroke rates up to 2,000 spm and cutting forces up to 20 kN. A prototype, which will be able to achieve higher stroke rates and cutting forces will be part of future work.

On Running a Machine through its Resonant Frequency

1956 ◽  
Vol 60 (549) ◽  
pp. 620-621 ◽  
Author(s):  
J. P. Ellington ◽  
H. McCallion
Keyword(s):  
High Speed ◽  
Exciting Force ◽  
Linear Mass ◽  
Running Speed ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Constant Rate ◽  
Summation Of Series ◽  
Spring System ◽  
Mass Spring

A solution, in terms of known integrals, is obtained for the motion from rest of a machine, idealised as an undamped linear mass-spring system, when subjected to an exciting force whose frequency varies at a constant rate.In many installations of modern high speed machinery the running speed of the machine is in excess of the resonant or natural frequency of the system, and consequently starting up or stopping the machine could result in vibrations of large amplitude. The problem of assessing the magnitude and duration of these vibrations is very complicated and has been solved analytically only for the case of a single degree of freedom system excited by an oscillating force whose frequency varies linearly with time. However, even this solution is not easy to evaluate, the integrals involved demanding either graphical construction and numerical integration or summation of series.

scholarly journals Research and Fabrication of Broadband Ring Flextensional Underwater Transducer

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1548
Author(s):  
Jiuling Hu ◽  
Lianjin Hong ◽  
Lili Yin ◽  
Yu Lan ◽  
Hao Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Structural Parameters ◽  
Low Frequency ◽  
Flexural Vibration ◽  
Underwater Acoustic Communication ◽  
Voltage Response ◽  
Water Tank ◽  
Spherical Cap ◽  
Finite Element Software ◽  
Underwater Transducer

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. The transducer realizes broadband transmission by means of the coupling between radial vibration of the piezoelectric rings and high-order flexural vibration of the spherical cap metal shells. The low-frequency directional transmission of the transducer is realized by using excitation signals with different amplitude and phase on two mosaic piezoelectric rings. The relationship between transmitting voltage response (TVR), resonance frequency and structural parameters of the transducer is analyzed by finite element software COMSOL. The broadband performance of the transducer is also optimized. On this basis, the low-frequency directivity of the transducer is further analyzed and the ratio of the excitation signals of the two piezoelectric rings is obtained. Finally, a prototype of the broadband ring flextensional underwater transducer is fabricated according to the results of simulation. The electroacoustic performance of the transducer is tested in an anechoic water tank. Experimental results show that the maximum TVR of the transducer is 147.2 dB and the operation bandwidth is 1.5–4 kHz, which means that the transducer has good low-frequency, broadband transmission capability. Meanwhile, cardioid directivity is obtained at 1.4 kHz and low-frequency directivity is realized.

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