Pin Wheel Research Articles

Modelling, simulation and experiment of a novel pure rolling cycloid reducer with involute teeth

A novel pure rolling cycloid planetary gear reducer is presented in this paper, which has a character of pin wheels’ pure rolling. It can eliminate the sliding friction between pin wheels and gears, and gain high transmission efficiency. The motion status of pin wheels in traditional dual-cycloid gear reducer is analysed in detail. Under the condition of pin wheels’ pure rolling, novel profiles of epicycloid and hypocycloid gears are designed. And then small involute teeth are added on the profiles, in order to constrain the tangential displacement of pin wheels. At last, kinematics simulation and experiment are employed to testify the validity and feasibility of the approach to the pure rolling cycloid gear reducer.

Fuzzy Robust Design of Cycloid Pin Wheel Reducer Based on Genetic Algorithms

Fuzzy robust design will be applied to optimal design of cycloid pin wheel reducer, and it is established that fuzzy robust optimal design mathematical model of cycloid pin wheel reducer in order to achieve the goal of the small size and high efficiency. Genetic algorithms correlation functions in MATLAB is used to solve the model, and optimal methods and calculation examples is given.

Whirling dervishes from Pinacidil to pinwheels

Whirling dervishes from Pinacidil to pinwheels

„A cacek też dużo było”. Zabawki dziecięce na ziemiach polskich w średniowieczu i w epoce nowożytnej

“The Toys Were Plentiful”. Children’s Toys in Polish Lands during the Middle Ages and the Modern EraChildren have been playing since time immemorial, with pebbles, sticks and fruit as their first playthings. In time games involved specially prepared objects. Different cultures and periods feature similar toys due to certain regularities of a child’s development and similarities governing the progress of societies. Children’s toys from the past can be divided into several groups taking into consideration such criteria as the child’s age and gender and the function of the given toy. The first group thus includes toys associated with infancy and early childhood, such as rattles. The slightly older child played with spinning wheels and pin wheels. At the consecutive stage toys differed depending on the child’s gender and future duties, with the youngsters imitating the observed occupations and behaviour of the adults. Girls “assuming” the roles of grown women had “girlish” toys preparing them for maternity – they played with dolls, which fulfilled the function of children, and the games of future housewives involved miniature cooking utensils and furniture as well as doll houses. Since masculine occupations were much more numerous and varied boys had their disposal miniature tools preparing them for assorted professional roles and crafts (boats, wagons). The most popular boys’ toys were connected with the military occupations of grown men – weapons, toy soldiers, and hobby horses. Children also played with religious objects while imitating priests officiating at funerals, celebrating Holy Mass, etc. With the passage of time, the development of civilisation, growing specialisations and the rise of new professions the range of toys increased and became diversified.

Finite Element Analysis for Cycloid Gear and pin Teeth of FA Cycloid Drive Based on ANSYS

In order to validate the force analysis between cycloid gear and pin wheel, the paper built the contact FEM model of between cycloid gear and pin teeth, analyzed statically three-dimensional contact analysis for them and get their contact state. The calculation results coincided with the force analysis method and proved the correctness of the stress analysis theory.

Multiple Pin Wheel Flaps and Its Modification in Special Areas of the Scalp

ABSTRACTClosure of the defects in special areas of the scalp, such as forehead, above the ear and occipital protuberance produces distortion of the hairline, lifting of the eyebrow, lengthy scars and distortion of the ear. The treatment of this distortion presents a challenge, for which we had a very favorable response with modification of the original four flap closure in a pinwheel fashion as described by TR Vecchione.In our series of eight cases, five flaps were marked at various convenient degrees instead of four flaps as originally described. In scalp defects in and around the hairline the length of the five flaps results in a smaller scar, without changing the hairline, lifting the eyebrow or distorting the position of the pinna.How to cite this articleSingh G, Shetty NS. Multiple Pin Wheel Flaps and Its Modification in Special Areas of the Scalp. Int J Head Neck Surg 2012;3(2):73-75.

Electrochemical growth of Au architectures on glassy carbon and their evaluation toward glucose oxidation reaction

Arrow-like, flower, splintery flower-like and pin wheel Au architectures were obtained using cyclic voltammetry (I), differential pulse amperometry (II), square wave voltammetry (III) and second harmonic AC voltammetry (IV) as electrochemical methods of synthesis, named systems I, II, III and IV respectively. Architecture sizes were 610, 380, 590 and 480 nm, meanwhile crystal sizes were 48, 76, 120 and 210 nm, respectively. XRD patterns showed that systems I, III and IV preferentially exhibited the (111) plane and system II preferentially exhibited the (200) plane. The catalytic properties of the architectures were tested employing D-(+)-glucose at 10, 50 and 100 mM, where the results showed that two processes occur in the glucose electrooxidation: at ∼−0.2 V vs. NHE, glucose is oxidized to gluconolactone, and after at ∼0.3 V vs. NHE the successive oxidation of the gluconolactone by-product were carried out. Systems with the (111) preferential plane favor gluconolactone oxidation; while system II with the (200) plane enhanced glucose oxidation toward the gluconolactone by-product. Also, system II showed a higher current density with 26.4 mA cm−2 at 100 mM glucose.

Germany's green - energy gap

Germany stumbles in its move to replace coal and nuclear power with offshore wind energy. The six offshore wind turbines that REpower Systems began erecting near Germany's coast in 2004 make their older cousins look like pin wheels. Each one has three 61.5-meter blades, which in a good breeze make one revolution every 5 seconds, producing 5 megawatts of electric power.

Study on Movable Pins Input Type Trochoid Gear Reducer (1st Report)

A pin wheel type reducer having no eccentric input cam has been newly developed. This reducer consists of an input disc with a trochoidal shape groove, a train of movable pins which are arranged to the equivalent angular pitch, a fixed cam and a reduction cam. The difference between the number of teeth on the fixed cam and the number of teeth on the reduction cam is two or more. And this difference conforms to the number of the trochoidal shape lobes on the input cam. The fixed and reduction cam are meshed with the train of pins simultaneously. In cases in which the input cam rotates, the meshing points on two cams rotate along the trocoidal shape. At the full rotation of input cam, the reduction cam rotates oppositely through the reduced angle which is proportional to the difference in the number of teeth. It can get high torsional rigidity and keep the balanced and steady rotation. In this report, the motion principle is investigated, and the cam profiles are shown based on motion of the pins. And the design conditions of an undercutting avoidance are investigated using polar complex vector analysis.

Gear geometry of cycloid drives

According to differential geometry and gear geometry, the equation of meshing for small teeth difference planetary gearing and a universal equation of conjugated profile are established based on cylindrical pin tooth and given motion. The correct meshing condition, contact line, contact ratio, calculating method for pin tooth’s maximum contact point are developed. Investigation on the theory of conjugated meshing is carried out when the tooth difference numbers between pin wheel and cycloidal gear are 1, 2, 3 and −1, respectively. A general method called enveloping method to generate hypocycloid and epicycloid is put forward. The correct meshing condition for cycloid pin wheel gearing is provided, and the contact line and the contact ratio are also discussed.

Central axis flap methods

Extensively burned patients often lack ample healthy skin for autotransplantation. Scar contractures are then frequent. Here, we reconstructed contractures using flaps of remaining healthy skin around the recipient sites. In this report, we present four original scar contracture repair methods using subcutaneous pedicled flaps: (1) Propeller flap, (2) multilobed propeller flap, (3) scar-band rotation flap and (4) pin–wheel flap. The subcutaneous pedicle under the center of these various types of flaps allows these methods to be characterized as “central axis flap methods.” We have employed these flaps to treat mild scar contractures in the axilla and cubital fossa. These methods are easily manipulated to restore function and improve aesthetics of scar contractures.

Finishing of structured surfaces by abrasive polishing

A new polishing process for the finishing of structured optical elements was introduced by the authors. Abrasive polishing using pin type and wheel type polishing tools made of polyamide was applied to improve the surface roughness of structured molds exhibiting fly-cut and precision ground V-grooves. Surface roughness of abrasive polished sides of V-grooves was found to be about 5 nm Ra. Furthermore, material removal rates were determined according to Preston's equation resulting in increasing removal rates with increasing polishing pressure and relative velocity. Material removal in abrasive polishing of structured surfaces was observed to be caused mainly by two-body abrasion but also by three-body abrasion, depending on relative velocity and polishing pressure. Tribological investigations showed that in abrasive polishing of structures mainly micro-ploughing and less micro-cutting occurs.

GEOMETRY DESIGN AND ANALYSIS FOR TROCHOIDAL-TYPE SPEED REDUCERS: WITH CONJUGATE ENVELOPES

This paper illustrates the use of the envelope theorem for the geometric design of a cycloidal speed reducer. Specifically, it proposes two designs for a mathematical model with tooth differences: a pin wheel epitrochoid meshing - which is a cycloidal wheel (internal rotor) profile equidistant to an epitrochoid (or extended epicycloid) curve and a cycloida! wheel is generated by a pin wheel (external rotor) - and a pin wheel hypotrochoid meshing. These two contrasting structures differ in their equidistance to the epitrochoid (or extended epicycloid) curve and hypotrochoid (or extended hypocycloid) curve. Using the design result parameters, the analysis also compares contact forces and assesses curvature to determine whether the cycloidal wheel has a non-undercutting or continuous condition.

Geometric Design Using Hypotrochoid and Nonundercutting Conditions for an Internal Cycloidal Gear

This paper uses the theory of gearing to derive the mathematical model of an internal cycloidal gear with tooth difference. Whereas the outer rotor profile is based on a curve equidistant to a hypotrochoidal (or extended hypocycloid) curve, the inner rotor design generally depends upon type of use—e.g., when used as a speed reducer, it is a pin wheel. Therefore, this analysis proposes designs for both a gerotor and a speed reducer. Specifically, for an inner rotor used as a gerotor pump, it outlines a mathematical model to improve pump efficiency and derives a dimensionless equation of nonundercutting. For the speed reducer, it develops and demonstrates with numerical examples, a feasible design region without undercutting on the tooth profile or interference between the adjacent pins.

CRYPTANALYSIS OF HAGELIN MACHINE PIN WHEELS

A ciphertext-only attack on the pin wheel patterns of the Hagelin CD-57 Cryptographer is described. The method is also applicable to some earlier Hagelin machines of the pin wheel and lug variety, for example the M-209. The only prior knowledge required is the setting of the lugs and the plain text frequency for the language of the message. The method is extended to finding the lug and pin settings of the M-209 using a longer message.

Analytical Currents: Cooperative pinwheels

Analytical Currents: Cooperative pinwheels

Out-of-plane orientation of multilayer N2 films adsorbed on Grafoil at 20 K

A study of the out-of-plane tilt angle of adsorbed 15N2 molecules on Grafoil using the nuclear resonance photon scattering (NRPS) technique is presented. Molecular coverages between n=0.6 and 5.0 commensurate monolayers (CML) at 20K were studied. The tilts were determined by measuring the anisotropy ratio of resonantly scattered intensities from the 6324keV level in 15N with the photon beam parallel and perpendicular to the Grafoil planes. The results at n≤1CML are in good agreement with calculations based on molecular dynamic simulations (MDS). At n>1CML, it was possible to deduce only the average tilt angle of N2 molecules over all layers. However, by relying on the reported structural properties of N2 multilayers obtained by n-diffraction (ND), the tilt of N2 molecules in the various layers was deduced and compared with theoretical expectations. The measured anisotropy ratios seem to rule out the occurrence of a pinwheel (PW) structure at n<2.7CML predicted by MDS and Monte Carlo (MC) calculations.

NEW PHASES FOR THE ORIENTATIONAL ORDERING OF QUANTUM ROTORS : H2 ON HEXAGONAL BN

The phase diagram for the orientational ordering of 2D films of ortho–para H 2 mixtures has been explored for both commensurate and incommensurate monolayer coverages on hexagonal BN. NMR techniques were used to study ortho concentrations 0.30<x<0.74and temperatures 0.05 <T<4.2. Three distinctly different classes of line shapes were observed and we interpret these in terms of the different phases predicted for the orientational ordering in 2D. At high concentrations a Pake doublet line shape was observed which is characteristic of the pinwheel (PW) ordering predicted by Harris and Berlinsky. For intermediate concentrations a distinctive helmet shaped NMR line is observed which is the signature of a quadrupolar glass state. This line shape was seen only for commensurate coverages. At low concentrations (x<0.45) a new very sharply defined Pake doublet shape is seen which corresponds to a very narrow distribution of order parameters. We interpret this latter phase as a herringbone (HB) ordering.

Identification of Peanut Green Mosaic Virus Strains in India*

AbstractDuring field surveys, three peanut green mosaic virus isolates differing in symptomatology on groundnut and a few other hosts were collected. Ultrathin sections of infected groundnut leaflets showed cytoplasmic inclusions with pin wheels and scrolls. In enzyme‐linked immunosorbent assay they reacted strongly with antisera to peanut green mosaic and soybean mosaic virus antisera, and moderately with adzuki bean mosaic and peanut stripe virus antisera. All isolates also reacted positively with antisera to peanut eye spot, blackeye cowpea mosaic, pea seed‐borne mosaic, potato virus Y and tobacco etch viruses, and did not react with antisera to peanut mottle, bean yellow mosaic, bean common mosaic, clover yellow vein and sugarcane mosaic viruses. SDS‐PAGE analysis of purified virus preparations of the three isolates showed a single polypeptide with mol. wt. of 34,500 daltons. Based on these results, the three isolates are identified as biologically distinct strains of peanut green mosaic virus.

THE SWEDISH HC-9 CIPHERING MACHINE

The HC-9 ciphering machine was used in Sweden after World War II. It satisfied the need for a simple key-setting process and the requirement of resistance to cryptanalysis by reduction of the risk of error when operated. The machine uses a punched card system instead of pin wheels and a drum with 16 changeable mixed alphabets which interrelated with the card reading mechanism and rotates after each letter is enciphered. The enciphering/deciphering process is described along with the machine's operating principles.