Pin Wheel Research Articles

The ability in pottery production of the pottery producer group of Ban Phakkhaya village, Atsaphone district, Savannakhet province

study on the pottery production ability of the pottery producer group of Ban Phakkhaya village, Atsaphone district, Savannakhet province, with the objective: 1. Study on production process of the pottery producer group of Ban Phakkhaya village, Atsaphone district, Savannakhet province, 2. Study on the The ability in pottery production of the pottery producer group of Ban Phakkhaya village, Atsaphone district, Savannakhet province, the researchers use descriptive statistics to explain the process and ability of the samples with 3 heads of production group and collection data by open-ended questionnaire and observation. Findings from the study: There are 3 steps in the production process, such as the clay preparation process, the molding process, and the firing process. Equipment for production includes pin or hand wheel (phean), long-handled curved sword (ngao or hok), comb (Wi), a stick made from bamboo (Mai Tee Din), Krok or a square wooden (Mai Yieb Teen), design stick (Mai Lai), and string (Xerk). For the ability of pottery producers, each group made the same type and similar shape, using the same knowledge source from their ancestor, using only one kiln. The first group can produce 1.537 potteries, making revenue of about 18,720,000 kip per time. The second group can produce 1,675 potteries per time, making revenue of about 36,625,000 kip per time. The third group can produce 667 potteries, making revenue of about 10,180,000 kip per time. When calculated as the proportion per person in pottery production, the first group has the highest bility.

Analysis of the thermal lubrication characteristics of cycloid pinwheel transmission mechanisms in RV reducers

In this paper, the cycloidal pin wheel drive mechanism of the secondary drive component of the rotary vector (RV) reducer is studied. Under the condition of grease lubrication, considering tooth profile modifications and machining errors, we established a three-dimensional load-bearing contact analysis model of a cycloid pinwheel transmission mechanism. We studied the time-varying contact characteristics of the gear teeth and dynamic joint surfaces of the inner and outer races of a crankshaft bearing. Considering the thermal effects, we proposed an analysis model of the lubrication characteristics of cycloid pinwheel transmission mechanisms. We also studied the thermal lubrication properties, such as load de-formation, lubrication film thickness, contact pressure and temperature increase at the lubrication contact area. The accuracy of the model was verified by temperature experiments on the inner raceway of an RV reducer bearing and the evolution law of the dynamic thermal lubrication characteristics of the inner and outer races of the crankshaft bearing, the meshing gear tooth pair and the whole process of single pin tooth meshing were revealed. This study provides an effective method for analyzing the temperature increases of the key joints of RV reducers.

Research on Parametric Design Technology of Cycloidal Pin Wheel Reducer for Robot Based on Solid Works

In this paper, SolidWorks software and VB.net programming language are used to accurately design the cycloidal wheel of the cycloidal pin wheel reducer used in robot with 3D parameterization and the 3D model of cycloidal wheel is automatically drawn. It is beneficial to save and modify the drawings and reduce the workload of the designers. In batch design, the design model can be automatically updated by modifying the parameters of cycloidal wheel 3D model or drawing parameters.

The Effect of Elbow and Forearm Position on the Resisted Wrist Extension Test and Incidence of Sensory Disturbance of the Superficial Radial Nerve in Patients with Lateral Epicondylitis.

Background: The aim of this study is to determine the effect of elbow and forearm position on the resisted wrist extension test (RWET) in patients with lateral epicondylitis. We also looked at the incidence of associated sensory disturbance of the superficial radial nerve (SRN) and the effect of treatment of lateral epicondylitis on sensory disturbance. Methods: Sixty-three consecutive patients (68 limbs) with lateral epicondylitis and an equal number of age and gender matched volunteers were investigated. Patients with lateral epicondylitis were subdivided into two groups based on history of corticosteroid injection. We performed the RWET in four limb positions namely elbow extended and forearm pronated (EP), elbow flexed and forearm pronated (FP), elbow extended and forearm supinated (ES), elbow flexed and forearm supinated (FS). Sensory disturbance in the SRN was assessed using a Wartenberg pin wheel. Results: The positivity rate of the RWET was significantly higher in the EP position (100%) compared to the FP (66%), ES (62%) and the FS (24%) positions in limbs with lateral epicondylitis. The RWET was positive only in one subject in the EP position in the control group (1.5%). Sensory disturbance in the SRN territory was present in 63.2% of limbs and only two subjects (2.9%) in the control group. The incidence of sensory disturbance was significantly higher (74.5% vs. 48.3%, p < 0.05) in patients who did not have a corticosteroid injection. Conclusions: The sensitivity and specificity of the RWET is better when it is performed with the elbow in extension with the forearm pronated (EP); 63.2% of limbs with lateral epicondylitis were noted to have an associated sensory disturbance of the SRN and a corticosteroid injection seems to decrease the incidence of sensory disturbances. Level of Evidence: Level II (Diagnostic).

Metamaterial inspired pin wheel fractal shaped antenna using parasitic split ring resonator for modern wireless applications

This article presents the Pin Wheel Fractal Antenna (PWFA) loaded with Split Ring Resonator (SRR) for X-band and Ku-band wireless applications. The performance of the final iteration of the proposed PWFA has been improved with the loading of SRR in terms of reflection coefficient, bandwidth and gain. The proposed design is fed with 50 Ω microstrip line along with the quarter-wave impedance matching line. To obtain the resonance and radiation characteristics, ground plane length and width of matching line has also been optimized. The bandwidth and gain improved by 26.6% and 31.3% respectively in the first resonance (C-band) and by 16.5% and 8.1% respectively in second resonance (Ku-band) in SRR loaded structure. A prototype of the proposed PWFA is also fabricated and comparison of the simulated and measured results are found in good agreement. The overall dimension of the proposed design is 30 mm × 30 mm, which can be used for various commercial, military and mobile communication systems for C-band and Ku-band.

Lubrication characteristics of cycloid pin wheel transmission of RV reducer

In order to analyze the lubricating characteristics at different meshing points in the cycloid pin wheel transmission process, the cycloid gear teeth were discretized, combined with the kinematic analysis of the cycloid pin gear transmission and the contact analysis of the gear teeth. The progressive mesh densification method (PMD) was used to numerically solve the film thickness. The influence of the design parameters and process parameters on the lubrication characteristics was analyzed. The elastohydrodynamic lubrication and mixed lubrication characteristics at different contact points were obtained. The optimal meshing area of the cycloid gear tooth was determined, and the film thickness ratio, contact load ratio, maximum contact pressure at different points, average film thickness and roughness after contact deformation were analyzed. The conclusion of this study provides effective guidance for the research on the modification of cycloid gear teeth.

Study on transient contact performance of meshing transmission of cycloid gear and needle wheel in RV reducer

The model of rotor vector (RV) reducer was established by 3D software, and was imported into ANSYS Workbench for transient dynamic analysis. The stress distribution diagram and total deformation diagram of the gear tooth surface during the meshing process of the cycloidal wheel and the pin wheel were obtained, and the stress distribution law of the cycloidal wheel in the process was also obtained. Comparing the calculation results of Hertz formula with the results of finite-element analysis showed that the deviation are smaller and within the allowable range, which provides the theoretical reference for the optimisation of the cycloidal wheel.

Design and research of meshing mechanism of orchard monorail transporter

The monorail transporter of mountains orchard had a compact size, strong carrying capacity, and can be installed in complex terrain, which can better meet the requirements of orchard use, and had received extensive attention at home and abroad. In order to improve the performance of the monorail transporter’s meshing mechanism, this paper took the meshing mechanism as the research object, and designed the driving pin wheel with fixed pin teeth, the driving pin wheel with rotating pin teeth and a single-track model with four different tooth widths. The virtual prototype model of the meshing mechanism was built by ADAMS/View. The experimental data shows that the speed RMS value of the driving pin wheel with rotating pin teeth is increased by 135% compared with the driving pin wheel with fixed pin teeth during the meshing of the driving pin wheel and the single-track, and the contact force RMS value generated during the meshing process is reduced by 36%, and the tooth width of the single-track has less influence on the performance of the meshing mechanism. The experimental results show that the driving pin wheel of rotating pin teeth can significantly improve the performance of the meshing mechanism.

Dynamic Characteristics Analysis of Bearings Based on Modification Cycloidal Pinwheel Reducer

Taking the cycloid pin gear reducer as the research object, the bearing force of the cycloid pin gear reducer shaft is calculated under different modification amount. Based on the Hertz theory, the contact stress and deformation of the bearing under different modification amounts are calculated. Based on the transmission principle of cycloid pin wheel reducer, the model of cycloid wheel and bearing is established and the finite element analysis is carried out. The analysis showed that the Hertz theoretical solution is consistent with the finite element analysis solution, which showed the correctness of the finite element results. The stress and deformation of the bearing obtained under different modification amounts of the cycloid wheel are not changed much. It can indicate that the cycloid wheel modification has no significant influence on the bearing force. Therefore, the research content of this paper has certain reference value for the design and optimization of cycloid pinwheel reducer.

Experimental Studies on Torsional Stiffness of Cycloid Gear Based on Machining Parameters of Tooth Surfaces

Estimating the torsional stiffness has always been the primary issue in analyzing the dynamic characteristics of cycloid gears. The traditional method of obtaining torsional rigidity involves calculating the ratio of the input torque and rotation angle, treating the deformation of cycloid gear as a black box. In order to thoroughly understand the rotation angle caused by the local contact deformation of each cycloid pin gear, a Majumdar–Bhushan contact model and the finite element method are combined to express the normal contact stiffness. By multiplying the normal contact stiffness of each pin gear and the arm of normal contact force, the torsional stiffness of the cycloidal pin wheel system can be calculated. Experiments are conducted to establish the relationship between the torsional stiffness and roughness parameters of the machined tooth surface. The effect of input torque on the torsional stiffness has also been analyzed. This study formulates a relationship between the torsional stiffness and surface characteristics of cycloid gears, which can help improve their design and manufacture in the future.

Simulation and analysis of contact state between cycloid gear and pin wheels in RV reducer

By using the finite element method, the contact state between cycloid gear and pin wheels of RV reducer is simulated and analyzed. The comparative analysis about the number of contact teeth pairs between cycloid gear and pin wheels, and the maximum values of contact stress under different working loads (output torques) is completed. The results show that the dowel pin hole on cycloid gear has a certain extent influence on the contact state between cycloid gear and pin wheels. With the increase of working load of RV reducer, the deformation quantity of dowel pin hole on cycloid gear also increasing, it makes the number of the contact teeth pairs between cycloid gear and the pin wheels increasing at the same time. Therefore, the deformation of dowel pin hole is beneficial to improve the contact state between cycloid gear and pin wheels.

PLANETARY CONTINUOUSLY ADJUSTABLE GEAR TRAIN WITH FORCE CLOSURE OF PLANET GEAR AND CENTRAL GEAR: FROM IDEA TO DESIGN

One of the reasons constraining use of a continuously adjustable gear train with compound poly-sector gear wheels in general and its most perspective version that is a planetary continuously adjustable gear train in particular is its design complexity. For example, a complex design of the mechanism for regulation of transmission gear ratio is specified by the use of involute gearing that requires a presence of backlash and bottom clearances for normal functioning and, therefore, autonomous but synchronous movement of a planet gear, as well as sectors of a central gear. In order to simplify the design of especially this mechanism for continuously adjustable gear train the paper justifies a transition to a backlash-free gearing and during this process either a planet gear or sectors of central gear are forcibly moving for regulation of the transmission ratio without losing contact with the mating element. Contact constancy of interacting elements under load is ensured by their force closure which is meant to overcome an action of gearing forces. The paper describes options for implementation of backlash-free gearing as a result of planet gear and central gear force closure, each variant is characterized by selection of active (controlled) and passive (execution of force closure) gear element. In the case of gear transmission with planet pinion coaxial tooth rims it is appropriate to implement a version with involute gearing, passive planet gear and active gear sectors of central gears. In the case of gear transmission with planet pinion opposite tooth rims the most acceptable option is with the cycloidal pin wheel gear, active planet gear and passive gear sectors of central gears. The paper proposes to carry out the force closure for teeth of gear components by means of an elastic element (a spring). A method for determination of parameters for an elastic element has been described depending on a planet gear design and the paper also shows simplification level in the gear design.

A biogeographic and ecological perspective to the evolution of reproductive behaviour in the family Salamandridae

Amphibians have a complex reproductive behaviour, which shows the highest diversity among tetrapodes. The family Salamandridae, distributed across the entire Holarctic, is one of the most diverse groups of extant salamanders comprising 114 species in 21 genera. The family has a remarkable diversity of courtship modes, amplexus and sperm transfer. It is often hypothesised that this diversity has evolved in adaptation to a specific mating and/or breeding habitat. We test this hypothesis based upon a phylogenetic reconstruction using the complete mitochondrial genome sequences of 45 Salamandridae species, representing all existing genera. We used ancestral character state reconstruction methods and geographic range models and applied relaxed Bayesian molecular clock models to discuss the results in a temporal framework of Salamandridae evolution. Our results show that the family Salamandridae started to diversify in the Late Cretaceous (ca. 87 mya) and is of Western Palearctic origin. Ancestral character state reconstruction predicts that its common ancestor was oviparous, mated on land without amplexus and probably showed a pin wheel spermatophore transfer, which is still found in the Italian endemic Salamandrina terdigidata. Our results suggest that several colonization of continents with subsequent radiations took place, once to the Nearctic and twice into Eastern Asian realms. However, these events were only in one case associated with a change in mating behaviour (dorsal amplexus in Nearctic newts). Around the Cretaceous-Paleogene boundary (K-Pg boundary) several Salamandridae lineages further diverged, again with no obvious changes in mating behaviour. Overall, there is no significant signal for mating character evolution being caused by changes in habitat type, with only a slight tendency that changes in mating habitat might have led to changes in the type of sperm transfer which in turn was associated with changes in the presence or absence of amplexus.

This 20-cent paper pinwheel could transform medicine in the developing world

This 20-cent paper pinwheel could transform medicine in the developing world

Mechanical Property of Internal Meshing Rotary Compressor

The internal-meshing rotary mechanism is widely used in the oil pumps and cyclonical pin wheels application. The working principle of the internal meshing rotary compressor is very different with the current institutions applications. while, the mechanical property method of the internal meshing rotary pump can’t be entirely and directly used in the rotary compressor because of the different working principles. In order to simplify the study of the internal-meshing rotary compressors, the forces acted on the inner and outer gears are computed. The gas force and torque related to the rotating angle are derived, and then compared with other rotary compressors. The result shows that the internal meshing rotary compressor’s mechanical parameters vary periodically and the period is 2π/Z2and this type of compressor has perfect mechanical property compared with other compressors.

Water Adsorption on TiOx Thin Films Grown on Au(111)

High resolution photoelectron spectroscopy has been used to investigate water adsorption on four different TiOx ultrathin film structures, grown on Au(111) by chemical vapor deposition. Two of the structures are reduced TiOx single layer phases, forming a honeycomb (HC) and a pinwheel (PW) structure, respectively. The other two phases have TiO2 stoichiometry, one in the form of islands and one in the form of a TiO2(B)(001) extended layer. Partial water dissociation is observed for all phases but the HC phase, and the dissociation propensity and adsorbate thermal stability structure result from interplay between the atomic structure of the particular TiOx phase and defects formed in the preparation. The dissociation on the TiO2(B) film is mainly related to different types of defect sites. The TiO2 islands, interpreted as surface reconstructed rutile TiO2(100), generate the highest amount of hydroxyls with a behavior consistent with reconstruction into a mixed (100) and (110) termination. Water dissociation on the PW layer can be assigned to particular sites of the structure and it stands out by leading to oxidation of Ti species.

Study on Meshing Force and Rigid-Flexible Coupling Dynamic Simulation of Cycloid Drive

The meshing force between pin wheels and gear teeth of modified and standard cycloidal gears is calculated. The parametric model of cycloidal gear and pin wheels is built. The flexible processing of cycloidal gear and pin wheel is conducted using Ansys software. The virtual prototype of cycloid reducer is built. The dynamic simulation of rigid-flexible coupling of modified and standard cycloidal gears has been developed, respectively. The meshing force with friction is calculated and the maximum equivalent stress is obtained. A comparison study of the meshing force using theoretical method is also carried out. It is significant to provide theoretical and technical supports for cycloidal gear design.

Rigorous Design of moving Sequencer Omission Tolerant Atomic Broadcast

This article investigates a mechanism to tolerate omission failure in moving sequencer based atomic broadcast at distributed systems. Various mechanisms are already given for moving sequencer based atomic broadcast like RMP [1], DTP [2], Pin Wheel [3] and mechanism proposed by [4]. But none of these mechanisms are efficient to tolerate different failure. Scholarly observation is that, these algorithms can tolerate only crash failure but not capable to tolerate omission or byzantine failure. This work is an extension of [4]. This work proposes a mechanism to tolerate omission failure in moving sequencer based atomic broadcast. Hence this work is a refined version of [4]. This work relies on unicast broadcast hence it will introduce a very less number of messages in comparison to previous mechanisms [5]. B [6] has been used as formal technique for development of proposed model. B uses set theory as a modeling notation, refinements to represent system at different abstraction level. Pro B [7] has been used as model checker and animator for constraint based checking, to discover errors due to invariant violation and for deadlocks, thereby, validating the specifications.

Analysis for Assembly Dimension Chain of RV Reducer

According to the statically indeterminate structure feature of RV reducer, the assembly relation between the parts such as support flange, crankshaft, cycloid gear, pin wheel, pin gear, sun gear and planet gear was analysed in order to meet the assembly condition and the meshing clearance, the assembly dimension chain of RV reducer was established. The conditions which should be met about upper deviation, lower deviation and tolerance of the close-chain and compositive rings among the assembly dimension chain was put forward based on extreme value method, it is very important for the product design, manufacture and assembly of RV reducer.

Part Design and Analysis of Cycloid Installation Systems

Cycloidal gear requires rigidly a certain working environment, so its installation and part designing also calls for the greatest care. This paper intends to analyse and design the structure of system components and to conduct a feasibility study based on actual requirements. Three-dimensional drawing software is applied to aid to minimize any error in part designing and upgrade the designing efficiency. Cycloidal pin wheel is featured by compact structure, small volume, light weight, high efficiency, smooth operation, good load capacity and performance against impact and vibration. However, at the same time, owing to its complex structure, difficult manufacture, high demand of precision for processing and assembly, it is very important to design the cycloidal gear system