scholarly journals Study on Swing Movable Teeth Drive with External Generating Wave Mode

Mechanika ◽  
2019 ◽  
Vol 25 (3) ◽  
pp. 240-247 ◽  
Author(s):  
YI Yali ◽  
JIN Herong ◽  
GAO Yunfei ◽  
HE Lei
Keyword(s):  
Wave Mode ◽  
Gear Ratio ◽  
Ring Gear ◽  
Analysis Model ◽  
Compact Structure ◽  
Quintic Polynomial ◽  
Wave Generator ◽  
Large Gear ◽  
Physical Prototype ◽  
Steady Rotation

An external generating wave swing movable teeth drive based on sinusoidal acceleration and quintic polynomial motion has been newly developed. This drive consists of a wave generator as the input cam, a train of movable rollers which are uniformly distributed on the fixed separator, and a ring gear as the output cam. The teeth difference between the ring gear and the rollers is two. The input and output cam are engaged with the train of rollers simultaneously. The drive thus has the advantages of large gear ratio, compact structure, high torsional rigid and steady rotation, can be integrated with pulley drive to form a pulley reducer. In this paper, the motion principle is studied and the tooth profiles are derived. On this foundation, curvature of the ring gear and pressure angles of the drive are conducted. And kinematic simulation is also carried out. A physical prototype is manufactured to demonstrate the feasibility and correctness of the theoretical analysis model of the drive. This drive can be integrated with pulley drive to form a pulley reducer, which is promising for the fields needing compact structure and large transmission ratio.

scholarly journals Modeling, Testing, and Characteristic Analysis of a Planetary Flywheel Inerter

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Zheng Ge ◽  
Weirui Wang
Keyword(s):  
Theoretical Analysis ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Ball Screw ◽  
Ring Gear ◽  
Characteristic Analysis ◽  
Planetary Gears ◽  
Nonlinear Dynamical ◽  
Output Force ◽  
New Type

We propose the planetary flywheel inerter, which is a new type of ball screw inerter. A planetary flywheel consists of several planetary gears mounted on a flywheel bracket. When the flywheel bracket is driven by a screw and rotating, each planetary gear meshing with an outer ring gear generates a compound motion composed of revolution and rotation. Theoretical analysis shows that the output force of the planetary flywheel inerter is proportional to the relative acceleration of one terminal of the inerter to the other. Optimizing the gear ratio of the planetary gears to the ring gear allows the planetary flywheel to be lighter than its traditional counterpart, without any loss on the inertance. According to the structure of the planetary flywheel inerter, nonlinear factors of the inerter are analyzed, and a nonlinear dynamical model of the inerter is established. Then the parameters in the model are identified and the accuracy of the model is validated by experiment. Theoretical analysis and experimental data show that the dynamical characteristics of a planetary flywheel inerter and those of a traditional flywheel inerter are basically the same. It is concluded that a planetary flywheel can completely replace a traditional flywheel, making the inerter lighter.

scholarly journals Detailed analyses of stall force generation inMycoplasma mobilegliding

2017 ◽  
Author(s):  
Masaki Mizutani ◽  
Isil Tulum ◽  
Yoshiaki Kinosita ◽  
Takayuki Nishizaka ◽  
Makoto Miyata
Keyword(s):  
Optical Tweezers ◽  
Type Strain ◽  
Wild Type Strain ◽  
Gear Ratio ◽  
Solid Surfaces ◽  
Force Generation ◽  
Wild Type ◽  
Step Size ◽  
Large Gear ◽  
Stall Force

ABSTRACTMycoplasma mobileis a bacterium that uses a unique mechanism to glide on solid surfaces at a velocity of up to 4.5 µm/s. Its gliding machinery comprises hundreds of units that generate the force for gliding based on the energy derived from ATP; the units catch and pull on sialylated oligosaccharides fixed to solid surfaces. In the present study, we measured the stall force of wild-type and mutant strains ofM. mobilecarrying a bead manipulated using optical tweezers. The strains that had been enhanced for binding exhibited weaker stall forces than the wild-type strain, indicating that stall force is related to force generation rather than to binding. The stall force of the wild-type strain decreased linearly from 113 to 19 pN following the addition of 0–0.5 mM free sialyllactose (a sialylated oligosaccharide), with a decrease in the number of working units. Following the addition of 0.5 mM sialyllactose, the cells carrying a bead loaded using optical tweezers exhibited stepwise movements with force increments. The force increments ranged from 1 to 2 pN. Considering the 70-nm step size, this small unit force may be explained by the large gear ratio involved in theM. mobilegliding machinery.SIGNIFICANCEMycoplasmais a genus of bacteria that parasitizes animals. Dozens ofMycoplasmaspecies glide over the tissues of their hosts during infection. The gliding machinery ofMycoplasma mobile, the fastest species, includes intracellular motors and hundreds of legs on the cell surface. In the present study, we precisely measured force generation using a highly focused laser beam arrangement (referred to as optical tweezers) under various conditions. The measurements obtained in this study suggest that the rapid gliding exhibited byM. mobilearises from the large gear ratio of its gliding machinery.

A PLANETARY GEAR TRAIN WITH RING-INVOLUTE TOOTH

2008 ◽  
Vol 32 (2) ◽  
pp. 251-266
Author(s):  
Shyue-Cheng Yang ◽  
Tsang-Lang Liang
Keyword(s):  
Planetary Gear ◽  
Conjugate Problem ◽  
Gear Ratio ◽  
Gear Train ◽  
Tooth Surface ◽  
The Sun ◽  
Ring Gear ◽  
Planetary Gear Train ◽  
Envelope Method ◽  
Planet Gear

This paper proposes a planetary gear train with ring-involute tooth profile. Inherent in a planetary gear train is the conjugate problem among the sun, the planet gears and the ring gear. The sun gear and the planet gear can be obtained by applying the envelope method to a one-parameter family of a conical tooth surface. The conical tooth rack cutter was presented in a previous paper [5]. The obtained planet gear then becomes the generating surface. The double envelope method can be used to obtain the envelope to the family of generating surfaces. Subsequently the profile of a ring gear of the planetary gear trains can be easily obtained, and using the generated planet gear and applying the gear theory, the ring gear is generated. To illustrate, the planetary gear train with a gear ratio of 24:10:7 is presented. Using rapid prototyping and manufacturing technology, a sun gear, four planet gears, and a ring gear are designed. The RP primitives provide an actual full-size physical model that can be analyzed and used for further development. Results from these mathematical models are applicable to the design of a planetary gear train.

scholarly journals A Three-Dimensional Finite Element Analysis Model for SH-SAW Torque Sensors

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4290 ◽  
Author(s):  
Jiang ◽  
Chen ◽  
Cho
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Quartz Substrate ◽  
Three Dimensional ◽  
Wave Mode ◽  
Analysis Model ◽  
Element Analysis ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this paper, a three-dimensional finite element analysis (3D-FEA) model for shear horizontal surface acoustic wave (SH-SAW) torque sensors is presented. Torque sensors play a significant role in various fields to ensure a reliable torque transmission in drivelines. Featured with the advantages of high propagation velocity, large Q-value, and good power capacity, SH-SAW based torque sensors are promising but very few studies have been carried out. In order to develop a successful sensor, understanding the characteristics of SH-SAWs produced on piezoelectric substrates and torque sensing modes is indispensable. Therefore, in this study, we first investigated the effect on the generation of waves when different Y-cut quartz substrates are engaged. Thereafter, analyses and comparisons, regarding the effect on the polarized displacement, wave guidance, and wave mode, were conducted for different configurations of wave-guide layer thickness to wavelength ratios (hlayer/λ) and materials. Results show that Y-cut quartz at an angle close to 36° with a gold (Au) layer varying from hAu/λ = 0.02 to 0.03 thickness could be the most effective configuration for the excitation of SH-SAWs, compared to other combinations using platinum (Pt), titanium (Ti) and silicon dioxide (SiO2). Finally, based on the FEA SH-SAW torque sensor model configuring with a Y+36° quartz substrate and 0.025 λ-thick gold layer, the relationship between the applied torque and sensed voltage was examined, which shows a perfect linearity demonstrating the performance of the sensors.

Effect of compliance location in series elastic actuators

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1313-1318 ◽  
Author(s):  
Jonathon W. Sensinger ◽  
Lawrence E. Burkart ◽  
Gill A. Pratt ◽  
Richard F. ff. Weir
Keyword(s):  
Gear Ratio ◽  
Large Gear ◽  
Class 1 ◽  
In Series ◽  
Ratio Dependent ◽  
Series Elastic Actuators ◽  
Series Elastic ◽  
Instrumentation Design

SUMMARYSeries elastic actuators have beneficial properties for some robot applications. Several recent implementations contain alternative placements of the compliant element to improve instrumentation design. We use a class 1 versus class 2 lever model and energy-port methods to demonstrate in this paper that these alternative placements should still be classified as series elastic actuators. We also note that the compliance of proximal series elastic actuators is reflected by an augmented gear ratio dependent on the nominal gear ratio, which is significant for small gear ratios and approaches unity for large gear ratios. This reflected compliance is shown to differ depending on the sign of the gear ratio. We demonstrate that although the reflected compliance is only marginally influenced by the magnitude of the gear ratio, there are several notable differences, particularly for small gear ratios.

Research on Aerodynamic Damping of Bladed Disk With Random Mistuning

2017 ◽  
Author(s):  
Lin Li ◽  
Xiaoping Yu ◽  
Peiyi Wang
Keyword(s):  
Travelling Waves ◽  
Elastic Stability ◽  
Travelling Wave ◽  
Wave Mode ◽  
Analysis Model ◽  
Aerodynamic Damping ◽  
Bladed Disk ◽  
Random Mistuning ◽  
Value Of It ◽  
Wave Modes

This paper presents an investigation on the aerodynamic damping of bladed disk (also called ‘blisk’) with mistuning. The study focuses mainly on the mechanism of the effect of random and intentional mistuning on the aero-elastic stability of blisk. For the purpose, aero-elastic stability equations of tuned and mistuned blisk in the frequency domain are established. NASA-Rotor37 is taken as the analysis model. In order to obtain the aerodynamic damping, the unsteady aero-elastic forces are calculated by the double channel harmonic method based on phase correction with aid of the general software CFX. Considering the stochastic characteristics of random mistuning, statistical analysis on the aerodynamic damping of mistuned blisk is performed. The effects of mistuning with different levels are compared. The mechanism of the effects of mistuning on the aero-elastic stability of blisk is found that mistuning couples the modes of different travelling waves and it concentrates the aerodynamic damping in a travelling wave-mode-family by increasing the aerodynamic damping ratios in forward travelling wave modes and decreasing the aerodynamic damping ratios in backward travelling wave modes. And the higher the mistuning level, the more obvious the trend. Furthermore, the following result is obtained: Whatever the mistuning level, in a traveling wave-mode-family, the aerodynamic damping of mistuned blisk is greater than the minimum aerodynamic damping of corresponding tuned blisk and less than the maximum value of it. Besides, the harmonic order of intentional mistuning that can be used to raise the aero-elastic stability of blisk is proposed.

Contact Ratio of Spatial Helix Gearing Mechanism

2012 ◽  
Author(s):  
Y.-Z. Chen ◽  
Z. Chen ◽  
Y. Zhang
Keyword(s):  
Gear Ratio ◽  
Design Methods ◽  
Contact Ratio ◽  
Compact Structure ◽  
Numerical Examples ◽  
Design Formula ◽  
Impacting Factors ◽  
Tooth Number ◽  
Driving Wheel

The contact ratio of spatial helix gear is deduced, and impacting factors of the contact ratio are analyzed. Then different design methods of contact ratio are discussed. The contact ratio could be designed flexibly. The theoretical gear ratio could be expanded to 36 with compact structure. The least tooth number of the driving wheel should be only 1. Numerical examples illustrate the design formula of contact ratio and the kinematics performance of the spatial helix gearing mechanism.

Kinematic Design of a Novel Two Degree-of-Freedom Parallel Mechanism for Minimally Invasive Surgery

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Wen-ao Cao ◽  
Shi-jie Xu ◽  
Kun Rao ◽  
Tengfei Ding
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Parallel Mechanism ◽  
Screw Theory ◽  
Degree Of Freedom ◽  
Compact Structure ◽  
Minimally Invasive Surgical ◽  
Physical Prototype ◽  
Two Degree Of Freedom ◽  
Surgical Manipulator

A novel two degree-of-freedom (2-DOF) parallel mechanism with remote center-of-motion (RCM) is proposed for minimally invasive surgical applications in this paper. A surgical manipulator with expected three-rotation and one-translation (3R1T) outputs can be obtained by serially connecting a revolute pair (R) and a prismatic pair (P) to the mechanism. First, kinematics of the new mechanism is analyzed and the corresponding velocity Jacobin matrix is established. Then, singularity identification of the mechanism is performed based on screw theory. Further, main dimensions of the mechanism are designed, and a physical prototype is developed to verify the effectiveness of executing RCM. The proposed mechanism has relatively simple kinematics, and can obtain a noninterference and nonsingularity cone workspace with the top angle of 60 deg based on a compact structure.

scholarly journals ANALISIS PENGARUH RASIO FINAL GEAR TERHADAP KECEPATAN DAN KONSUMSI BAHAN BAKAR MOBIL HYBRID URBAN KMHE 2018

2020 ◽  
Vol 8 (3) ◽  
pp. 59
Author(s):  
Koerniawan Hastho Poetro
Keyword(s):  
Data Collection ◽  
Fuel Consumption ◽  
Fuel Efficiency ◽  
Gear Ratio ◽  
Ring Gear ◽  
Test Results ◽  
Finish Line ◽  
Speed Test ◽  
Pinion Gear ◽  
Travelling Time

In automotive world, differential ratio also known as final gear ratio. It consist of pinion gear and ring gear. Final gear ratio will be affecting car speed and fuel consumption that can be achieved. Research will be performed by experiment and data collection will be displayed through descriptive methode. Research began by selecting 2 kind of final gear ratio which are 1,27 and 2,53. Those ratios have been achieved by selecting pinion gear 15 and 30 teeth and ring gear 38 teeth, which are common and easy to find on the market. Testing performed by running the car on the tarmac testing track, 2800 meters (4 lap @700 meters), from stop until reached finish line with limited the speed test by 30 km/h and 40 km/h. Each test will be performed 5 times and the data collection will be displayed by tabulation and chart. The test results shown pinion gear with 30 teeth have less travelling time, less engine rotation and better fuel efficiency compare with pinion gear 15 teeth. Pinion gear 30 teeth have 8,9% better fuel consumption on 30 km/h speed and 4,7% better fuel consumption on 40 km/h.

Internal Gear Strains and Load Sharing in Planetary Transmissions: Model and Experiments

2007 ◽  
Author(s):  
Avinash Singh ◽  
Ahmet Kahraman ◽  
Haris Ligata
Keyword(s):  
System Analysis ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Load Sharing ◽  
Companion Paper ◽  
System Level ◽  
Outer Diameter ◽  
Ring Gear ◽  
Analysis Model ◽  
Position Errors

This paper presents results of a comprehensive experimental and theoretical study to determine the influence of certain key factors in planetary transmissions on gear stresses and planetary load sharing. A series of tests are conducted on a family of planetary gear sets, and strains are recorded at various locations on the outer diameter and gear tooth fillet of the ring gear. Pinion position errors are introduced as a representative key manufacturing tolerance, and the resultant changes in the planetary behavior are observed. The experimental data is compared to the predictions of a state-of-the-art multi-body contact analysis model — ‘Gear System Analysis Modules’ (GSAM). This model is capable of including the influences of a number of system-level variables and quantifying their impact on gear strains. The model predictions are shown to compare well with the measured strain at the ring gear outer diameter and tooth fillet. GSAM predictions of planet load sharing are then used to quantify the influence of pin hole position errors on the 3, 4, 5, and 6 planet test gear sets. These predictions also agree well with the planet load sharing experiments presented in a companion paper [20].

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