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The present invention is a variable-ratio line gear mechanism. The mechanism forms a transmission pair consisting of a driving line gear and a driven line gear, of which axes intersect at an arbitrary angle. Transmission is generated by point contact meshing movement of line teeth between the driving line gear and the driven line gear. A contact curve of the line tooth is designed in accordance with space conjugate curve meshing theory, and the designing equation is divided into an equal transmission ratio part and a variable transmission ratio part. The equal transmission ratio part provides a uniform transmission, and the variable transmission ratio part makes the transmission ratio smoothly transit. The line gear mechanism is able to provide periodically transmission with variable transmission ratio, to provide a plurality of transmission ratios during a movement period of the driven line gear, and to enable smooth transitions between respective transmission ratios in accordance with movement rules.

Transmission ratio change in today’s motor cycle rubber belt Continuously Variable Transmission (CVT) are based on centrifugal forces resulted from engine revolution. Compare to manual transmission, this kind of CVT needs higher engine revolution to start engaging the transmision ratio which in turn requiring more fuel consumption. A transmission ratio change concept based on an Electro-mechanical actuator consisting of cam, actuator gears and DC motor has been developed to eliminate the dependancy of transmission ratio on engine revolution. The DC motor rotates the cam through actuator gears. The rotation of the cam causes the primary movable pulley sheave to move in axial direction, which in turn changing the belt-pulley pitch radius and changing the transmission ratio. This research aims to design and implement an electronic measurement system based on Arduino Uno as a data acquisition system and Matlab/Simulink as a controller program to obtain the measurement data of primary pulley and secondary pulley speeds and primary pulley axial position. Based on these data, the transmission ratio can be determined and the relationship between transmission ratio and primary pulley posistion can then be obtained. For future development, these measurement data will be used as important references when developing and testing the transmission ratio controller programs.

[ES] Este proyecto tiene como objetivo mejorar el rendimiento en competición de la motocicleta Yamaha RD350, mediante el rediseño y modificación de algunos de los piñones de su caja de cambios. Lo cual se hará atendiendo a las indicaciones del piloto de la motocicleta basadas en su experiencia en circuito. El objetivo principal será reducir la caída de revoluciones que se produce en cada cambio de marcha, para que el régimen de giro del motor permanezca en el rango óptimo de funcionamiento y así aprovechar al máximo la potencia del mismo., [EN] This project aims to improve the racing performance of the Yamaha RD350 motorcycle, by redesigning and modifying some of the gears of its gearbox. This will be done according to the indications of the pilot of the motorcycle based on his experience in the circuit. The main objective will be to reduce the revs drop that occurs in each gear change, so that the engine speed remains in the optimal operating range and thus take full advantage of the power of the same., [CA] Aquest projecte té com a objectiu millorar el rendiment en competició de la motocicleta Yamaha RD350, mitjançant el redisseny i modificació d’alguns dels pinyons de la seua caixa de canvis. La qual cosa es farà atenent a les indicacions del pilot de la motocicleta basades en la seua experiència en circuit. El principal objectiu serà reduir la caiguda de revolucions que es produeix en cada canvi de marxa, de manera que el règim de gir del motor es mantingui prop del rang òptim de funcionament i així aprofitar al màxim la potència d’aquest.

In the article was discussed the possibility of using decisive logical trees and predominant variables for the analysis of automatic gearboxes. The purpose of modeling an automatic gearbox with graphs can be versatile, namely: determining the transmission ratio of individual gears, analyzing the speed and acceleration of individual rotating elements. In a further step, logic tree decision methods can be used to analyze functional schemes of selected transmission gears. Instead, for graphs that are models of transmission, parametrically acting tree structures can be used.

The paper deals with a construction design of the rack system which will be used for storage of metallurgical rod material in a manufacturing engineering company. To meet requirements for manual control of the pull-out mechanism its design with the sufficiently large transmission ratio will be proposed in order to handle a rack block weighing up to three tones. Then, for structure safety and reliability verification stress analysis will be conducted. This work has been supported by KEGA project No. 015ŽU-4/2017.

This paper proposes the novel concept titled as pseudo harmonic transmission ratio (PHTR) in permanent magnet vernier motor (PMVM) for in-wheel traction. The PHTR is equivalent to the mechanical gear in conventional transmission. Hence, the torque expressions of PMVM and PMSM plus mechanical gear are both derived and analyzed by theoretical analysis and FEA respectively. Moreover, the output capability of PMVM with same PHTR is compared with the PMSM plus mechanical reduction gear under the same in-wheel space. Meanwhile, in order to evaluate the harmonic discount degree comparing with the mechanical reduction gear, the harmonic transmission factor k htf is introduced and defined in PMVM, which will contribute to further understanding the harmonic working principle. Finally, the results between theoretical analysis and FEA method match well, which exactly validates the accuracy of results.

Extinction ratio is one of important parameters which are characterization of optical properties of Glan-Taylor prism (GTP) .In this paper, we adopt the ray tracing method to deduce the extinction ratio expression of the GTP. By performing the computer simulation, some important relationship curves are obtained as the variations of the extinction ratio on optical axes and the structural angle, the work has great guiding significance in the design and use of Glan-Taylor prism.

Robotic systems for object handling and manipulation are hugely important for modern engineering and industry, with their efficiency, agility and robustness often depending on gripper design and performance. In this work, we investigate a gripper design that, when driven by a twisted string actuator, exhibits nearly-constant transmission ratio throughout its motion range. This allows for design of a highly-compact, modular and efficient robotic gripper driven by a low-power motor. We investigate kinematics of the device, experimentally verify developed models with a practical gripper testbed, and analyze transmission ratio and efficiency of the designed device. The resulting system has a nearly-constant transmission ratio of 550, with the constancy coefficient of 0.985.

The pure electric minivan is different from electric car. In order to achieve goals of optimum power performances, combined with certain van, we use the orthogonal optimization algorithm to optimize the design parameters. Then, establish simulation models and operate tasks calculation of the transmission ratio in Cruise. Simulation results show that: the design of optimum transmission ratio met requirements of power performances. This paper has practical guiding significances on providing a new way of electric minivan match and simulation analysis.

In this paper, we propose an accurate and practical model for the estimation of surface-breaking discontinuity (i.e., crack) depth in concrete through quantitative characterization of surface-wave transmission across the discontinuity. The effects of three different mixture types (mortar, normal strength concrete, and high strength concrete) and four different simulated crack depths on surface-wave transmission were examined through experiments carried out on lab-scale concrete specimens. The crack depth estimation model is based on a surface-wave spectral energy approach that is capable of taking into account a wide range of wave frequencies. The accuracy of the proposed crack depth estimation model is validated by root mean square error analysis of data from repeated spectral energy transmission ratio measurements for each specimen.

In this paper, we introduce a new concept of biomechanical energy harvester that can harvest electrical energies from wearers performing various activities of daily living such as walking and running. Due to a trade-off between the amount of electric-power generation and the degree of keeping user's natural movements, the transmission ratio of the wearer's angular velocity to that of the electromagnetic generator needs to be adjusted for several factors as physical properties of the wearer, gait patterns, and environmental conditions. To make it possible, our harvester is equipped with a Continuously Variable Transmission (CVT) system. We developed a prototype of our harvester attached to a knee joint, and conducted preliminary experimental evaluations with human subjects in walking and running using the prototype. Experimental results suggest that changing the transmission ratio according to individual and gait speed is beneficial to maximize the capacity of harvested electric energy from the wearer without suppressing natural movements, thereby proving our concept.

Based on the coaxial HPGHP system experiments, the mathematical model of the various components of the coaxial HPGHP system is established to research the matching relations between the drive system and the load demand of the compressor. This paper establishes the thermal efficiency of the engine model based on load rate, to maintain the thermal efficiency always be above 0.25, combined with the thermal efficiency map of the engine, the best economic zone of engine operation is determined. Finally, Torque optimization model of the coaxial HPGHP system was proposed, the transmission ratio of the HPGHP system was optimized and mode control strategy of the coaxial HPGHP system was determined. Simulation results show the thermal efficiency of the HPGHP system can be always been guaranteed above 0.25 and the transmission ratios are respectively 2.9, 1.8 and 1.4 in three different load demand range.

In this paper is presented mathematical modelling and analyzing of nominal conveying ability of toothed belts with STD profile. For the designer and constructor of transmitters with toothed belts determination of nominal conveying ability for the respective belt profile has special practical importance. Under this power the constructor for the concrete conditions in which transmitter would worked, determine the conveying ability, respectively power which can carry the transmitter. From the mathematical expressions for each of the profiles STD belts through MathCAD program, are gained diagrams from that we can see change of nominal conveying ability, depending on the number of rotations of the driving pulley, and its kinematic diameter. Expressions for nominal conveying ability given in the paper are for the transmission ratio i = 1. When nominal conveying ability multiplied by factor, which takes into account, the impact of the belt width, then is obtained corrected conveying ability.

Multispeed gears are noncircular gears whose kinematics varies during a rotational period, alternating uniform and variable motions. Due to the limited information on multispeed gears design and performance, the paper presents i) the generation of multispeed gears, using the design hypothesis of the transmission ratio variation and ii) investigations on meshing conditions, as a qualitative information on gears contact. To generate multispeed gears, the gears transmission ratio are defined by hybrid multiple parameters functions with parabolic and trigonometric variations. Virtual models of the multispeed gears, produced by the Matlab-PHP-MySQL-AutoCAD interference, are further used for the gear meshing analysis, the theoretical static contact evolution and distribution along the teeth being investigated and compared for both kinematics. It was found that the trigonometric variation of the gears transmission ratio improves the gears meshing in gear concave zones, while the parabolic variation has benefits on tooth contact pattern in zones where the gears centrodes geometry is changed from circular to noncircular shapes.

In order to extend the type of multi-lobed non-circular bevel gear, some curves such as an Archimedes spiral, a quadratic curve and a Pascal curve are applied to the design of the pitch surface of a multi-lobed non-circular bevel gear. With the aim of studying the design defects of a multi-lobed non-circular bevel gear which has a pitch surface with a concave cusp or a convex cusp, a novel pitch-surface-shaping method is presented to shape the concave cusp or the convex cusp of the pitch surface of a multi-lobed non-circular bevel gear. A section of the pitch surface of the cutter is used to replace the concave or convex pitch surface of the multi-lobed non-circular bevel gear by using the above shaping method. Mathematical models of the pitch surface with multi-stage space curves for a multi-lobed non-circular bevel gear are established. Numerical examples demonstrate that the shaping method is beneficial for improving the machining quality of the teeth profile as well as the transmission performance of a multi-lobed non-circular bevel gear.

Barrier properties are achieved in PET food packaging by using additives, coatings or multi-layers. An analytical model to predict the contamination during multiple recycling steps of this packaging is proposed. This model shows that lower contents of non-PET materials should be achieved to promote a valid recycling chain. A possible solution is using nano-technologies because of the very small amount of added material. Results are shown in the case of PVD coatings with aluminum target, and PET nano-composites. In both cases, less than 0.1 wt% of aluminum is able to reduce the oxygen transmission ratio of the PET packaging down to 50% of the virgin PET sheet.

This paper proposes an approach to optimize the fuel economy of a two-speed electric vehicle (EV) in car sharing business through Genetic Algorithm and ADVISOR co-simulation. The ADVISOR simulation model built including dynamics, fuel cell, storage battery and motor. Under NEDC working condition, the two-speed gearboxmodeled, modeled and the optimal combination of transmission ration and main reduction ratio is found by genetic algorithm to improve fuel economy.

It is hard for normal traffic to travel on rugged road and polluted for the environment. So a new multi-legged walking machine with double mixed power is designed. The machine is made up of several parts, including mechanic walking part with eight legs, transmission part with two gears, two electric control footboards, two power motors and a folded beach umbrella. Detailed explanation of designed idea and process for mechanic walking legs is made. Detailed explanation of transmission ratio, circuit diagram and working principle for gear transmission is made as well. It makes simulation analysis for mechanic legs by software AUTODESK INVENTOR. The result shows that moving distance and strength are satisfied and meet standard.

In order to improve the driving range of two-speed pure electric vehicle (EV), within the constraint of EV power performance, and the optimization objective is the minimum vehicle energy consumption under the NEDC (New European Driving Cycle) drive cycle, transmission ratios of an EV were optimized by using genetic algorithm (GA) under the economy shift schedule. The driving range and the power performance before and after transmission ratio optimization were analyzed. Simulation results show that the proposed optimization algorithm is effective, and the driving range improves by 1.73% and the acceleration time increases by 0.006s after optimization, but still meets the requirements of vehicle power performances.

A novel pitch curve design method for non-circular bevel gear is presented to simplify design of non-circular bevel gear. Pitch curve equation for non-circular bevel gear is deduced based on geometrical relationships between pitch cone surface of non-circular gear with parallel axis and spherical surface. Then, transmission ratio function is transformed into pitch curve design defects modification equation and mathematical expression between modification factor and pitch curve design parameters for non-circular bevel gear is derived. By using the expression, modification value of pitch curve can be determined rapidly and accurately. Simulation results for high-order elliptical bevel gear and Pascal curve bevel gear demonstrate that the proposed modification method can be applied to pitch curve design for other types of non-circular bevel gear. Design and verification efficiency for non-circular bevel gear are improved effectively by employing the proposed pitch curve design defects modification method.

Some peculiarities of frontal frictional mechanisms with cylindrical centroidal schemes and the external contacts of wheels, which ensures the continuous gradual variation of the transmission ratio of a mechanism, are considered. The solution of general issues of dynamics related to the selection of values of the parameters of the mechanism is based on the formulation of the “Vyshnegradskiy problem.”

In order to evaluate friction losses from chain drives, an important aspect to regard is the friction between chain and guide. This paper is proposing a mathematical model and simulation of the chain-guide contact, for a reference chain drive with transmission ratio equal to 1. The transmission is subject of further experimental determination of friction losses.

In this paper alternate mechanism for design and analysis of small size stone crusher mechanism is proposed. The basic idea is to optimize the design of the crusher which would be best suited for stone which need crushing force of 3 Tons. Presently for reducing sizes of stones from 10cm x 10cm to 2.5cm x 2.5cm in quarries is laborious job and is done manually our approach is to design a best optimum mechanism for said conditions.

In this paper the authors present the construction of a modular processing device, fitted by collet mechanisms. A research study of the operation indicators and its specific performance were made for the designed device. In this study the axial errors were eliminated by using a mobile supporting disc, front supported on the collet mechanisms housing, possibly on main shaft. The functionality conditions of the collet mechanisms were established taking into consideration the force transmission ratio and the mechanism efficiency.

The paper resumes the traditional hypotheses for the noncircular mating centrodes design, based on the definition of i) the driving centrode geometry ii) the transmission ratio variation and iii) the rotational motion of the driven centrode. Each procedure is transferred within the gear theory and developed considering both specific gear data, such as gear modulus, gear number of teeth and gear number of rotations during a rotational period. Original codes are developed in Php amd MyQSL to illustrate gears conjugate pitch curves geometry and their kinematics for external rolling.

For the problem of generating oval gear tooth profile and driving characteristic, desgin the tooth profile of oval gear by the conversion method of tooth profile, and get its three-dimensional modal by Pro/E. The transmission characteristics of a pair of ovate gear are researched; it would help to further study wire cutting of the oval gear based on the involute profile ,which got by the conversion of method of tooth profile, and the driving characteristic help to study other characteristics of oval gear as well as the application in the machinery.

A multi-objective optimization method for the optimization of the efficiency and weight of helicopter transmission planetary gear train was established. Taking the transmission ratio, efficiency weight, and reliability as critical design parameters, taking the conditions of the planetary gear train itself and the strength check constraint for the gear train as constraint functions, making the weight and efficiency of the planetary gear train asoptimization targets and using the Matlab function fgoalattain, a multi-objective optimization has been made. Comparison between the initial and the optimized results showed the success of the optimized planetary gear train in reducing the weight and increasing the efficiency.

In this paper, the mathematical model based on modern design methods of machinery used to optimize the parameters of the two-stage chain transmission system was established. The optimization toolbox of Matlab was introduced as well. Optimization results showed that, the pitches of first and second-stage chains were 19.05 and 25.4 respectively; compared with the original scheme, transmission ratio of first-stage chain decrease from 2.57 to 1.77, while the second-stage increase from 1.0 to 1.45. The number of chain strands of second-stage chain decreased from 2 to 1. The teeth number of the driven sprocket of the first-stage chain decreased also from 59 to 41. Total weight of the sprockets of the chain transmission system decreased from 25.40 kg to 14.84 kg, at least 41.57% material was saved and not less than 50% production cost was reduced. The optimization method is simple, feasible and the optimized parameters are reliable in practice.

The paper presents an approach to design optimization of robot gripper mechanism. There are two different optimization criteria, a force transmission ratio and a displacement transmission ratio, considered. In order to generate the optimal solutions, three algorithms are applied. There are gradient based method, random search method and evolutionary algorithm used. The results and a comparison with the industrial gripper, show possibility to improve parameters of the gripper mechanism using optimization procedure. They show as well, that conventional algorithms often fail during optimization process and the most suitable methods in this case are evolutionary algorithms.

The control design for the variator in a pushbelt continuously variable transmission (CVT) is investigated. The variator enables a stepless variation of the transmission ratio within a finite range. A conventional variator control design is typically obtained by the use of a variator model, which incorporates large uncertainties and, therefore, limits the variator efficiency. In this paper, a variator control design is proposed, which simultaneously satisfies the variator control objectives: 1) tracking a transmission ratio reference, 2) optimizing the variator efficiency. Furthermore, the variator control design, which consists of a combination of extremum seeking control (ESC) and tracking control (TC), only uses measurements from sensors that are standard. Experiments illustrate that the variator control design achieves the variator control objectives and show that a conventional variator control design is outperformed.

Pulley strain aggravated whole-Part abrasion, affected friction and lubricates state of metal belt continuously variable transmission. Pulley strain was analyzed by analytical method and finite element analysis. The results indicate that with the increase of transmission ratio, the driver pulley compressive strain is increases after reduces for a while, and the driven pulley increase. Compressive strain dense when radius is lesser and vice versa. Two methods results are basically the same, whereby demonstrating that the model is rational and that the analysis results are reliable.

A ZI worm and helical gear drive is composed of an involute helicoid worm and a helical gear. Its application is limited due to less studies on the transmission performance with a large transmission ratio. In this paper, the design method of the drive is developed as: the parameters of the ZI worm should be the same as those of the helical gear; the helix angle β1 and the reference diameter factor d1∗ of the ZI worm should be greater than the minimum values proposed. The TCA of the drive shows that: the contact areas on the tooth surfaces are narrow; the effective face width of the ZI worm is larger than that of the helical gear; the contact ratio is less than 2; when the number of threads of the ZI worm changes from 1 to 5, the contact ratio decreases slightly, the effective face width of the worm decreases and that of the helical gear increases correspondingly. The instantaneous transmission ratio is proved theoretically to be constant and the assembly errors cause small shifts of the paths of contact.

Metasurfaces present excellent performance in acoustic wave control with subwavelength thickness, but are typically studied and built for fixed applications. This paper looks at a convenient tunable metasurface design with Helmholtz resonance. Moving sliders in the design allow full phase shift with a high transmission ratio in a broad frequency bandwidth. The design can be used for tunable wave front redirection, focusing with varying wavelengths and sound source illusion, as are shown in numerical and experimental examples. This design could be a superb option when there is a need for tunable acoustic wave modulation.

This article considers work stability of a system with two-channel regulation of an autonomous electric drive’s speed, where the first channel is a high-torque drive, where the engine is connected through a gear unit with reducing transfer factor; and the second – high-speed with the similar motor is directly connected. The power summation is realized by using the differential gear unit. It is shown that the stable work can be achieved by a fixation of a speed setting through one channel, and the regulation through the other channel at the same time; control algorithms are shown. Optimal values of transmission ratio of high-torque drive gear unit j = 4 are defined, as well as a turn-on factor (rate of participation in transient process) of high-torque motor with its transient process time minimum.

The paper summarizes the principle of applying velocity graphic method to analyze Simpson planetary gear mechanism, which provides guidance for analysis procedure. The movement of each element in the mechanism can be intuitively understood through drawing the linear velocity vectors of three constant velocity points. The similar triangle principle is used to calculated transmission ratio of each transmission scheme in the linear velocity vector diagram, and the correctness of the analysis method and process is verified by the transmission ratio calculated by velocity graphic method and analytic method.

We attempt to optimize the structure of double web on aviation herringbone gear with a big transmission ratio. We established an optimization mathematical model of the big aviation herringbone gear web, developed an optimization calculation procedure based on APDL language. The web structure of big aviation herringbone gear in a helicopters main gearbox has been optimized. We calculated the dynamic response of the gear web before and after optimization and proved that our method can improve its dynamic characteristics, reduce its stress level and achieve good results.

According to some of the original data on the machine lathe develop some parameters, according to the proposed parameters, transmission scheme compared to determine the transmission scheme. Calculate the transmission ratio of the transmission and gears vice parameters, and the gear and shaft strength, stiffness checked.

In order to ensure the necessary economy and power performance indexes of car, it was necessary to configurate reasonable transmission gear and transmission ratio. Taking 6 tons truck as an example, two methods were designed according to geometric progression and offset geometric transmission ratio. The results show that the method of bias geometric distribution ratio is superior to the method of geometric distribution.

Improving the driving range and driving performance are critical for pure electric vehicles (EV). Transmission ratios directly affects drivability and economy of EV. This paper analyzed the impact of various transmission ratios on the performance of EV, verified the vehicle performance with different transmission ratios by simulation with models built with GT-drive software, and based on EV performance requests, optimized the EV transmission ratios, presents single reduction gear and multi-speed transmission ratio scheme respectively, compared the EV performance with these two transmission schemes respectively, simulation results show that multi-speed transmission system can improve the performance of electric vehicle on dynamic and economy.

This paper deals with the choice of motor and transmission with reference to the dynamic operating range of the motor and to the general case in which there is alternation of the power direction through the reducer. The paper proposes a method in which the resolving diagrams are obtained starting from the distinction between two different load torques, characterized by only direct and only inverse efficiency of the transmission respectively. In order to make the correct choice of the reducer to be coupled with a given motor, the paper also proposes a diagram that relates the transmission ratio and both the efficiencies. The guidelines for an automatized identification of all the admissible drive system-transmission couples are delineated and an industrial case study is discussed.

To test the hydraulic steering by-wire system whether can achieve the ideal steering characteristics, firstly take experimental tests of the full hydraulic steering system, getting the transmission ratio curve. Then the simulation for the hydraulic steering by-wire system by MATLAB showed that simulation results combined with the test curve, the hydraulic steering by-wire system satisfy the requirement of vehicle working.

As the reason for large transmission ratio, small center distance and interference on translational motor body, the design method of involute gear for translational meshing motor was proposed. In order to get appropriate tooth profile parameters, the trail calculation considering the conditions of interference and coincidence degree were applied using the tooth profile parameters calculated from given module, number of teeth, pressure angle and modification coefficient. The internal meshing gears was designed and processed based on proposed method. The novel translational meshing motor using designed involute gears operates successfully and efficiently which testify the validity and feasibility of proposed method.

According to the engineering requirement of extruder, a new spatial worm cam drive and its corresponding design method due to mechanism’s special use requires were introduced .In this paper, the worm cam’s axes and the index plate’s axes were vertical. It is the main purpose that the index plate with pin rotated without lash, while the worm cam rotated with the same speed in a certain speed. When the transmission ratio was i, the follower rotated by an angle in different speed intermittently without impact as the driving part made one rotation in the same speed. In this paper, non-impact is in the condition which the driven work in the principle of sinusoidal acceleration and the worm cam’s design equation will be provided.

During optimization of transmission ratios, dimension difference of power performance and fuel economy indicators exists. Aiming at this problem, large bus model based on Matlab is built and verified, a normalization processing method of optimization goal is proposed. Through normalization processing of power performance and fuel economy indicators of the optimization goal, the dimension difference problem is eliminated. An optimization example is conducted, proving the method is feasible.