KINEMATIC ANALYSIS OF ROLLER DRIVES

The roller drive is an epicyclic gearing that consists of both the planet gear and the annular sun gear with rollers as its teeth. The roller drive thus has the advantages of easy manufacturing and low cost, and also has attractive attributes including high speed reduction ratio, compact size, and light weight as an epicyclic gearing. In this paper, a mathematical modeling for the kinematic analysis based on the vector loop approach is developed. The position, velocity, and acceleration analyses for the roller drive are performed. Furthermore, an experimental test verifying the analysis results is achieved. The analysis results show that only a single pair of teeth is meshed during gearing. It also shows that the values of gear ratio are inherently fluctuated corresponding with the number of ring gear rollers. This undesirable fluctuation can be minimized if the selected values of the design parameters satisfy a specific four-linkage constraint.

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A new compact and wideband CPW-fed sleeve antenna

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720000070 ◽

2020 ◽

Vol 12 (6) ◽

pp. 513-518

Author(s):

Peyman Hasani ◽

Seyed Mohammad Hashemi ◽

Javad Ghalibafan

Keyword(s):

High Efficiency ◽

Low Cost ◽

Coplanar Waveguide ◽

Equivalent Circuit Model ◽

Good Choice ◽

Design Parameters ◽

Impedance Bandwidth ◽

Frequency Bands ◽

Compact Size ◽

Metallic Cylinder

AbstractIn this article, a sleeve antenna with a wide impedance bandwidth that consists of a coplanar waveguide line connected to a metallic cylinder is presented. The effect of design parameters on the impedance bandwidth is considered by some simulations. In addition to the wide impedance bandwidth, the omnidirectional pattern, high efficiency, low cost and easy fabrication process, and compact dimensions cause this antenna to be a good choice for some applications at low VHF/UHF frequency bands. Due to the flexible structure of this antenna, it is possible to cover the various frequency bands by changing the parameters of the antenna. In this work a typical model of the proposed antenna for the frequency range of 127 to 586 MHz is fabricated and compared with other previous works. An equivalent circuit model has been proposed to better understand how the antenna works. The proposed antenna has a bandwidth of about 128.7% for a voltage standing wave ratio (VSWR) of less than 3, compact size of 0.274λ × 0.047λ and higher than 90% efficiency.

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Active meta polarizer for terahertz frequencies

Scientific Reports ◽

10.1038/s41598-020-71990-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Hang Wong ◽

Kai Xu Wang ◽

Laure Huitema ◽

Aurelian Crunteanu

Keyword(s):

High Speed ◽

Phase Change Materials ◽

High Efficiency ◽

Low Cost ◽

Single Layer ◽

Intense Laser ◽

Laser Source ◽

Terahertz Waves ◽

Compact Size ◽

Thz Waves

Abstract Active meta polarizers based on phase-change materials have recently led to emerging developments in terahertz devices and systems for imaging, security, and high-speed communications. Existing technologies of adaptive control of meta polarizers are limited to the complexity of external stimuli. Here, we introduce an active terahertz polarizer consisting of a single layer of large array patterns of vanadium dioxide material integrated with metallic patch matrix to dynamically reconfigure the polarization of the terahertz waves. The proposed active polarizer is simple in structure and can independently manipulate the polarization of the incident THz waves in two orthogonal directions. In addition, the device can also be performing as a highly efficient reflector at the same frequencies. We demonstrate that efficient and fast polarization changes of THz waves can be achieved over a wide operating bandwidth. Compared with other active polarizers using mechanical, optical and thermal controls, it can be conveniently manipulated with DC bias without any external actuators, intense laser source or heater. Therefore, with the advantages of high efficiency, compact size, low loss, low cost and fast response, the proposed polarizer can be highly integrative and practical to operate within adaptive terahertz circuits and systems.

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Dual-/Tri-Wideband Bandpass Filter with High Selectivity and Adjustable Passband for 5G Mid-Band Mobile Communications

Electronics ◽

10.3390/electronics9020205 ◽

2020 ◽

Vol 9 (2) ◽

pp. 205 ◽

Cited By ~ 8

Author(s):

Zhanyong Hou ◽

Chengguo Liu ◽

Bin Zhang ◽

Rongguo Song ◽

Zhipeng Wu ◽

...

Keyword(s):

Mobile Communications ◽

Communication Systems ◽

High Speed ◽

Bandpass Filter ◽

Low Cost ◽

Open Loop ◽

Structural Deformation ◽

Compact Structure ◽

Compact Size ◽

5G Mobile Communications

The design and implementation of the filters for the fifth-generation (5G) mobile communication systems are challengeable due to the demands of high integration, low-cost, and high-speed data transmission. In this paper, a dual-wideband bandpass filter (BPF) and a tri-wideband BPF for 5G mobile communications are proposed. The dual-wideband BPF consists of two folded open-loop stepped-impedance resonators (FOLSIRs), and the tri-wideband BPF is designed by placing a pair of folded uniform impedance resonator inside the dual-wideband BPF with little increase in the physical size of the filter. By employing a novel structural deformation of a stepped-impedance resonator, the FOLSIR is achieved with a more compact structure, a controllable transmission zero, and an adjustable resonant frequency. The measurement results show that the working bands of the two filters are 1.98–2.28/3.27–3.66 GHz and 2.035–2.305/3.31–3.71/4.54–5.18 GHz, respectively, which are consistent with the full-wave EM simulation results. The implemented filters have a compact size and the results show low loss, good out-of-band rejection, and wide passbands covering sub-6 GHz bands of 5G mobile communications and a commonly used spectrum.

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On the Kinematic Error in Harmonic Drive Gears

Journal of Mechanical Design ◽

10.1115/1.1334379 ◽

1998 ◽

Vol 123 (1) ◽

pp. 90-97 ◽

Cited By ~ 75

Author(s):

Fathi H. Ghorbel ◽

Prasanna S. Gandhi ◽

Friedhelm Alpeter

Keyword(s):

High Speed ◽

Mechanical Design ◽

Basic Component ◽

Kinematic Error ◽

Harmonic Drive ◽

Space Applications ◽

Speed Reduction ◽

Positioning Systems ◽

Compact Size ◽

New Perspective

Harmonic drive gears are widely used in space applications, robotics, and precision positioning systems because of their attractive attributes including near-zero backlash, high speed reduction ratio, compact size, and small weight. On the other hand, they possess an inherent periodic positioning error known as kinematic error responsible for transmission performance degradation. No definite understanding of the mechanism of kinematic error as well as its characterization is available in the literature. In this paper, we report analytical and experimental results on kinematic error using a dedicated research Harmonic Drive Test Apparatus. We first show that the error referred to in the literature as kinematic error actually consists of a basic component, representing “pure” kinematic error, colored with a second component resulting from inherent torsional flexibility in the harmonic drive gear. The latter component explains the source of variability in published kinematic error profiles. The decomposition of the kinematic error into a basic component and a flexibility related component is demonstrated experimentally as well as analytically by matching a mathematical model to experimental data. We also characterize the dependence of the kinematic error on inertial load, gear assembly, and rotational speed. The results of this paper offer a new perspective in the understanding of the mechanism of kinematic error and will be valuable in the mechanical design of harmonic drive gears as well as in the dynamic modeling and precision control of harmonic drive systems.

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A New Type of Aerostatic Thrust Bearing Controlled by High-speed Pneumatic Valve and a Novel Pressure Transducer

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.16.4.2019.16.0550 ◽

2019 ◽

Vol 16 (4) ◽

pp. 7430-7446 ◽

Cited By ~ 1

Author(s):

Waheed Ur Rehman ◽

Guiyun Jiang ◽

Yongqin Wang ◽

Nadeem Iqbal ◽

Shafiq Ur Rehman ◽

...

Keyword(s):

High Speed ◽

Thrust Bearing ◽

Low Cost ◽

Research Work ◽

Pressure Sensors ◽

Open Loop ◽

Machining Process ◽

Feedback Signal ◽

Aerostatic Bearing ◽

Compact Size

The current research work presents a low cost, efficient and innovative active aerostatic thrust bearing which is controlled through a combination of the Arduino board, feedback transducers and high-speed valves. The purpose is to make low cost, compact active aerostatic thrust bearing with overall small dimensions and compact size. A prototype design is done in solid works with small dimensions and components are produced with the help of the high precision machining process. There are two high-speed electropneumatic valves which are controlled through pulse width modulation techniques. These high-speed electro-pneumatic valves modify the supply pressure of aerostatic bearing to achieve desired air height gap. There are two novel pressure sensors which provide a feedback signal for control. The test bench to perform experiments has been explained. The performance of the proposed aerostatic bearing is checked both in open loop and closed loop configuration with respect to static and dynamic conditions.

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Mathematical and software for the study of the dynamics of the finished rolling mill block wire mill

Fundamental and applied problems of ferrous metallurgy ◽

10.52150/2522-9117-2018-32-394-401 ◽

2018 ◽

pp. 394-401

Author(s):

V.I. Bolshakov ◽

K.P. Lopatenko ◽

A.M. Yunakov ◽

A.A. Chernyshev

Keyword(s):

Rolling Mill ◽

High Speed ◽

Block Design ◽

Objective Assessment ◽

Gear Ratio ◽

Design Parameters ◽

Technical Solution ◽

Wire Mill ◽

Linear Differential ◽

Design Calculations

The aim of the work is the development of mathematical and software for the study of transients arising from the management of the finishing unit of the mill of the rolling mill 150. The movements, speeds, accelerations and torques in various connections of the finishing unit were studied. The linear mechanical analogue in the form of an extensive system of discrete masses connected by elastic-dissipative elements was used to estimate the integral characteristics of the block load. Block design calculations include engines, a distribution gearbox, two transmission shafts for rolling rolls of horizontal and vertical stands of the block. The mathematical model for analyzing the oscillation frequencies of a block is represented by a system of second-order linear differential equations. The equations for changing the drive current in the armature circuit of the motor and in the excitation circuit, equalizing the motion of the armature (rotor) of the electric motor, the equations for determining the motor torque are presented. . According to the results of studies of the mill 150, the range of rolling speeds outside the resonant zones was established and the possibility of increasing the rolling speed by 10% was justified. Analysis of the frequencies, the level and nature of dynamic loads allowed us to develop a technical solution to reduce the dynamics of the drive line by changing the gear ratio of the gearbox. The study of the dynamics of the rolling unit of the first in Ukraine high-speed double-strand wire mill 150, put into operation at the Makeevka metallurgical combine, allowed an objective assessment of the optimality of the design parameters of its equipment, reliability and guaranteed life.

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Development and production experience of the multilayer curtain-coated linerboard of Ji’an PM No. 3,

TAPPI Journal ◽

10.32964/tj13.2.17 ◽

2014 ◽

Vol 13 (2) ◽

pp. 17-25

Author(s):

JUNMING SHU ◽

ARTHAS YANG ◽

PEKKA SALMINEN ◽

HENRI VAITTINEN

Keyword(s):

Titanium Dioxide ◽

High Speed ◽

Food Packaging ◽

Production Efficiency ◽

Positive Impact ◽

Low Cost ◽

Board Structure ◽

Flexographic Printing ◽

Curtain Coating ◽

Coating Formulations

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.

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IoT based e-Healthcare System to Enable Remote Patient Care based on Cloud Server

International Journal of Advanced Research in Computer Science and Software Engineering ◽

10.23956/ijarcsse.v7i7.94 ◽

2017 ◽

Vol 7 (7) ◽

pp. 36

Author(s):

P.Venu Gopala Rao ◽

Eslavath Raja ◽

Ramakrishna Gandi ◽

G. Ravi Kumar

Keyword(s):

Low Cost ◽

Vital Signs ◽

Smart Phone ◽

Medical Professional ◽

Design Parameters ◽

Cloud Server ◽

Significant Area ◽

Efficient Data ◽

System Data ◽

Remote Patient

IoT (Internet of Things) has become most significant area of research to design an efficient data enabled services with the help of sensors. In this paper, a low-cost system design for e-healthcare service to process the sensitive health data is presented. Vital signs of the human body are measured from the patient location and shared with a registered medical professional for consultation. Temperature and heart rate are the major signals obtained from a patient for the initial build of the system. Data is sent to a cloud server where processing and analysis is provided for the medical professional to analyze. Secure transmission and dissemination of data through the cloud server is provided with an authentication system and the patient could be able to track his data through a smart phone on connecting to the cloud server. A prototype of the system along with its design parameters has been discussed.

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Kinematic analysis and deformation of a planar lattice with an arbitrary number of panels

10.36652/0042-4633-2020-9-15-19 ◽

2020 ◽

pp. 15-19

Author(s):

M.N. Kirsanov

Keyword(s):

Exact Solution ◽

Kinematic Analysis ◽

Arbitrary Number ◽

Design Parameters ◽

Lattice Deformation ◽

Planar Lattice ◽

Force Loading

Formulae are obtained for calculating the deformations of a statically determinate lattice under the action of two types of loads in its plane, depending on the number of panels located along one side of the lattice. Two options for fixing the lattice are analyzed. Cases of kinematic variability of the structure are found. The distribution of forces in the rods of the lattice is shown. The dependences of the force loading of some rods on the design parameters are obtained. Keywords: truss, lattice, deformation, exact solution, deflection, induction, Maple system. [email protected]

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