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This scientific paper presents original research and the authors personal views on the technical-economic and practical acceptance of pulley and inclined plane applications in transport engineering. Engineering specialists appreciate that the active type experiment carried out by practical determinations leads to concrete, important results in the field addressed. In order to demonstrate theoretically and practically what the specialists say, we have made a small-scale laboratory model in which we have experimented with situations similar to those encountered in real life. In this way, we have presented the front end of pulley systems used for lifting or towing damaged or damaged vehicles (motor vehicles) on trailer trailers, which are common in transport engineering. In this way, those interested can learn how these applications can be used in the laboratory but also in real life, the advantages and concrete results obtained when applied. Other experiments and applications of the laboratory mock-up are specified in the paper, in which the results, their usefulness, real-life applicability, how certain measuring instruments are used, the units of measurement and their conversions, as well as how to calculate the voltages occurring in lifting/pulling cables with pulleys are presented. The scale model can be successfully used in the laboratories of art and craft schools, high schools or colleges. In this way pupils or students can acquire practical knowledge in car knowledge or road vehicle dynamics laboratories. At the end of the work, conclusions in the field covered and further research directions are presented.

The field modulation magnetic gear transmission technology is based on the principle of field modulation to achieve efficient and contactless transmission, effectively improving the problems of low torque density and low transmission ratio caused by the low utilization of magnets in traditional magnetic gears. It is expected to replace mechanical gear transmission devices for promotion and application. The working principle of field modulation magnetic gears was introduced, field modulation magnetic gears were classified from the perspective of topological structure, and the structural characteristics and transmission performance of different types of modulation magnetic gears were compared. The application progress of field modulation magnetic gears was analysed and summarized in the field of the variable speed transmission.

In Older to analyze the transmission characteristics of non-circular gears in different transmission modes, Pascal worn line gear was taken as the research object, and the mathematical model of the Pascal worm line gear pitch curve was established in intern! meshing transmission, and a visualization platform for the transmission characteristics analysis of the Pascal worm line gear in internal meshing transmission was established by using MatLab based on the established mathematical model, the motion characteristics of the Pascal worm gear during internal and external meshing transmission were analyzed by using the developed visualization platform. The amplitude of the Pascal worm gear pair transmission ratio was affected by circle diameter occurs and exhibition length by compared and analyzed, and the Amplitude of the transmission ratio was not affected by the denatured coefficient, but position of the amplitude of the transmission ratio was affected by the denaturation coefficient. The range of transmission ratio variation during external meshing transmission was significantly larger than that during internal meshing transmission. In order to further explain the influence of transmission mode on motion characteristics, the guide bar mechanism was studied and analyzed as an example. If the transmission ratio changes greatly during design, the outer meshing transmission mode should be selected. If the transmission ratio change range is small and the structure is compact, choose the internal meshing transmission mode. [ABSTRACT FROM AUTHOR]

Research on electric wheel loaders (EWLs) has predominantly focused on battery management, hybrid technologies, and energy recovery. However, the influence of motor types and drivetrains on the drive performance of EWLs has received little attention in previous studies. This case study addresses this gap by examining different EWL configurations and analyzing the drive theory and force requirements by integrating classic vehicle theory with EWL-specific characteristics. The study compares an original EWL, equipped with Permanent Magnet Synchronous Motors (PMSMs) on both the front and rear axles with identical transmission ratios of 22.85, to a modified EWL, which features a Switched Reluctance Motor (SRM) on the front axle and a transmission ratio of 44.05. Walking and shoveling tests were conducted to evaluate performance. The walking test results reveal that, at motor speeds of 200 rpm, 400 rpm, and 600 rpm, energy consumption in R-drive mode is 68.56%, 71.88%, and 74.87% of that in F-drive mode when two PMSMs are used. When an SRM is applied with a transmission ratio of 44.05, these values shift to 73.90%, 70.35%, and 67.72%, respectively. This demonstrates that using the rear motor alone for driving under walking conditions can yield greater energy savings. The shoveling test results indicate that distributing torque according to wheel load reduces rear wheel slippage, and the SRM with a transmission ratio of 44.05 delivers sufficient drive force while operating within a high-efficiency speed range for the EWL. [ABSTRACT FROM AUTHOR]

Cycloidal gearboxes are part of power transmission systems that use a cycloidal disk instead of an involute gear to transmit power. The use of cycloidal gearboxes is limited due to complicated profile shapes, difficulties in fabrication, and lack of data in the design process of industrial gearboxes. The special mechanism of cycloidal disks provides a high conversion ratio in small dimensions in cycloidal gearboxes. In this research, the design of a cycloidal gearbox will be discussed. Firstly, the mechanism of cycloidal gearboxes will be introduced and its advantages will be described, the operation mechanism and main components will be explained and then a cycloidal gearbox for conversion of 1500 rpm into 32 rpm (conversion ratio 47) will be designed according to basic equations. The designed gearbox is modeled in SolidWorks software and analyzed in finite element software (Ansys software). The finite element results show that the principal stress and shear stress of the cycloidal disk and other parts of the gearbox were in the safe region of the design criteria. In addition, the rotational speed of the gearbox is not constant due to the eccentricity of the input shaft, and the average rotational speed is calculated based on the finite element results and agrees with the design value. [ABSTRACT FROM AUTHOR]

This scientific paper presents original research and the authors personal views on the technical-economic and practical acceptance of pulley and inclined plane applications in transport engineering. Engineering specialists appreciate that the active type experiment carried out by practical determinations leads to concrete, important results in the field addressed. In order to demonstrate theoretically and practically what the specialists say, we have made a small-scale laboratory model in which we have experimented with situations similar to those encountered in real life. In this way, we have presented the front end of pulley systems used for lifting or towing damaged or damaged vehicles (motor vehicles) on trailer trailers, which are common in transport engineering. In this way, those interested can learn how these applications can be used in the laboratory but also in real life, the advantages and concrete results obtained when applied. Other experiments and applications of the laboratory mock-up are specified in the paper, in which the results, their usefulness, real-life applicability, how certain measuring instruments are used, the units of measurement and their conversions, as well as how to calculate the voltages occurring in lifting/pulling cables with pulleys are presented. The scale model can be successfully used in the laboratories of art and craft schools, high schools or colleges. In this way pupils or students can acquire practical knowledge in car knowledge or road vehicle dynamics laboratories. At the end of the work, conclusions in the field covered and further research directions are presented. [ABSTRACT FROM AUTHOR]

This paper presents the design and experiment results for a W-band sheet beam electron gun of the extended interaction oscillator (EIO). A 3D simulation has been performed, and then, the structure parameters of the electron gun have been optimized. The simulation results show that the beam waist (BW) and transmission ratio are extremely sensitive to the distance between the cathode and the focus electrode. By observing the beam waist and the beam range, the maximum beam range is up to 46 mm, which is measured at the beginning of the beam-wave interaction cavity. In addition, the thickness of the beam waist decreases rapidly when the cathode is moved along the positive axial direction by 0.03 mm. Moreover, the voltage on the focus electrode has a significant impact on the beam trajectory. At last, by considering the deviation, experiment results show that the transmission is improved to 98%. [ABSTRACT FROM AUTHOR]

Research on electric wheel loaders (EWLs) has predominantly focused on battery management, hybrid technologies, and energy recovery. However, the influence of motor types and drivetrains on the drive performance of EWLs has received little attention in previous studies. This case study addresses this gap by examining different EWL configurations and analyzing the drive theory and force requirements by integrating classic vehicle theory with EWL-specific characteristics. The study compares an original EWL, equipped with Permanent Magnet Synchronous Motors (PMSMs) on both the front and rear axles with identical transmission ratios of 22.85, to a modified EWL, which features a Switched Reluctance Motor (SRM) on the front axle and a transmission ratio of 44.05. Walking and shoveling tests were conducted to evaluate performance. The walking test results reveal that, at motor speeds of 200 rpm, 400 rpm, and 600 rpm, energy consumption in R-drive mode is 68.56%, 71.88%, and 74.87% of that in F-drive mode when two PMSMs are used. When an SRM is applied with a transmission ratio of 44.05, these values shift to 73.90%, 70.35%, and 67.72%, respectively. This demonstrates that using the rear motor alone for driving under walking conditions can yield greater energy savings. The shoveling test results indicate that distributing torque according to wheel load reduces rear wheel slippage, and the SRM with a transmission ratio of 44.05 delivers sufficient drive force while operating within a high-efficiency speed range for the EWL.

To achieve the precise operation trajectory and posture required for pot seedling transplanting and solve the problem that the partial reversal of the transplanting arm's output in the double planet carrier transplanting mechanism, which is unconducive to the realization of the seedling pushing action, a motion synthesis method for a double planet carrier gear train mechanism with attitude constraints based on the output angle and four exact task poses is proposed. First, the ideal transplanting trajectory is planned according to the transplanting agronomic requirements, and the position and attitude information of the four key points on the ideal trajectory are extracted as the constraints of the mechanism design. Then, based on the relative displacement equation, a comprehensive design equation of the motion of the plane 3R mechanism (simplified model of the transplanting mechanism) about the output rotation angle and the precise four pose constraints is established, and the mechanism parameters that meet the constraint requirements are obtained by solving the multicellular homotopy method. A mathematical model of the roundness of the non-circular gear was also established, and the roundness of the transmission non-circular gears in the gear-train transplanting mechanism was optimized by using the genetic algorithm. Finally, the structural design, virtual simulation, and experimental analysis of the double-planet carrier gear train transplanting mechanism were completed. The results show that the actual trajectory and attitude are consistent with the theoretical design, and when then the mechanism was under the transplanting efficiency of 120 and 180 plants/min, the success rates of picking seedlings were 91.53% and 87.46%, respectively, meeting the design requirements. [ABSTRACT FROM AUTHOR]

In order to study the meshing efficiency of the gear pair under the actual working conditions, the force and kinematics of the contact surface of the gear pair are analyzed, the lubrication state of the gear pair is judged by combining the theory of elastohydrodynamic lubrication, and the relationship between the elastohydrodynamic lubrication and the mixed lubrication state is established. The mathematical model of the dynamic friction factor is used to obtain the friction factor of the gear pair at different meshing positions along the meshing line. From the point of view of force, the calculation formula of gear pair meshing efficiency is deduced, and the dynamic sliding friction factor is introduced to obtain the result of gear pair meshing efficiency that conforms to the actual working conditions. Combined with the simulation analysis software, the influence of the transmission ratio and the number of pinion teeth on the sliding friction factor and the meshing efficiency of the gear pair is analyzed. The results show that the calculation method of the gear pair meshing efficiency based on dynamic sliding friction factor is in good agreement with the actual working conditions, which has certain guiding significance for gear transmission design.

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An ultra-compact all-optical AND logic gate is realized using two-dimensional photonic crystal waveguides. These circuits are implemented on a photonic crystal substrate in an effort to develop energy-efficient, simple, and compact devices appropriate for photonic integrated circuits. The suggested device operates on the beam interference principle, which is feasible for operation at 1550 nm wavelength. Performance of the proposed device is analyzed by evaluating the several key parameters, including contrast ratio, transmission ratio, response time and bit rate using simulations employing the finite-difference-time-domain approach on Opti-FDTD software. The designs are purely silicon-based, which simplifies manufacturing and offers simple compatibility with both current opto-electronic systems and upcoming all-optical systems. Compared to traditional semiconductor optical amplifiers, quantum dots, and photonic crystal ring resonators, the suggested technology has a higher contrast ratio of 40.08 dB, less response time of 23.45 fs and higher bit rate of 42.64 Tbps at a wavelength of 1550 nm. [ABSTRACT FROM AUTHOR]

The existing deceleration systems in industrial robots often employ rotate vector (RV) or harmonic reducers to augment torque and decrease speed, yet achieving the motor's peak power proves challenging. Given the extremely high space-size demands for reduction systems in robotic applications, an innovative compact continuously variable transmission is suggested, leveraging the transmission characteristics of spatial gear trains and metallic V-belts. The proposed system utilizes the input of an eccentric shaft to drive the planetary pulley's rotation around the sun pulley. The pinhole, in cooperation with the eccentric shaft of the planetary pulley, achieves coaxial output of the transmission power. The article primarily explores the transmission and speed change mechanisms, then dissects the relationships between the transmission ratio and the effective radius of the pulley, the axial adjustment distance, and the factors influencing the pulley's wrapping angle. Further, we use the Lagrange equation to derive the input equation, establishing the correlation between the planetary pulley's rotation angle and system inertia, angular acceleration, angular velocity, and effective working radius over time. Finally, we simulate the continuously variable transmission's motion to examine speed changes in forward, reverse, and neutral states. A continuously variable transmission prototype and a testing platform are also constructed to assess performance parameters, specifically input and output torque, and rotational speed. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the transmission ratio error of a steel belt transmission device in a flexible base is large, the transmission principle and transmission law of the steel belt transmission device are analyzed. Firstly, the non-circular profile of the belt pulley is calculated, and the theoretical transmission ratio and the force characteristics of the steel belt are obtained. Then, a finite element simulation is used to simulate the steel belt transmission, and the effects of local plastic bending of the steel belt and stress concentration at the screw hole on the theoretical transmission ratio are analyzed. Finally, the error analysis of the experimental data of the flexible base is carried out, and the comparison of the experimental data and the simulation data shows that the two have a good agreement. In this study, the influence of belt profile, local plastic deformation and elastic deformation on transmission ratio is analyzed, and on this basis, the improvement scheme is put forward to make the belt transmission become accurate transmission.

A two-carrier planetary gear train (PGT) developed for a specific purpose is discussed in this paper. This PGT is suitable for applications which require negative transmission ratios in the range from - 3 up to - 143. The mechanical and dimensional characteristics of the planetary gear train for nominal negative transmission ratios of - 30 and - 40 have been considered. Many combinations of ideal torque ratios of the PGT were obtained for the mentioned transmission ratios, from which only the combinations providing the minimum radial dimensions of the planetary gear units were selected. It was found that the minimum radial dimensions of the PGT will be obtained when the ratio of the reference diameters of the planetary unit ring gears of is close to unity, i.e., when the PGT housing is cylindrical rather than stepped. An introduction to single speed two-carrier planetary gear trains is given, in addition to an overview of the application of the DVOBRZ software package used to synthesize different gearboxes for the required transmission ratio. Acceptable gearboxes were selected from all PGTs according to the criteria of minimum dimensions and acceptable efficiency, and their construction concepts were created. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A two-carrier planetary gear train (PGT) configuration, named S13WN, was developed for a specific application with a negative transmission ratio in the interval between -20 and -21. 72 valid combinations of component PGTs ideal torque ratios have been developed for this configuration, from which kinematically feasible combinations providing minimal dimensions and maximum efficiency within the required interval have been selected. The minimal dimensions of the PGT were achieved with a cylindrical case shape, i.e., with the ratio of the ring gears reference diameters close to unity. Nine other PGT configurations have been synthesized for the same transmission ratio, and their design parameters optimized. The two solutions that offer the most improvements over S13WN have been developed into design concepts.

The transmission ratio of NN reducer is discrete and nonlinear, and the gear matching method determines the volume and stability of a reducer. In previous studies， most scholars tried to find out the key parameters affecting the change of transmission ratio or the change rule of transmission ratio. However， the search method is complicated and tooth matching method is single. An improved differential evolution algorithm is proposed to search the transmission ratio. The constraint variables of the teeth in the transmission ratio are analyzed， and the global search of the transmission ratio and the matching method within the specified range is carried out by using the four-fold cyclic logic. An adaptive differential evolution algorithm is improved， and the forced intervention differential evolution algorithm based on the change of the optimal trait is proposed， which adjusts the mutation operator timely based on the change process of the optimal trait in each evolutionary period. Taking the solution of the maximum transmission ratio as an example and based on the global search results， the possibility of using differential evolution algorithm to solve the transmission ratio problem of NN reducer is verified.

With the increasing proportion of pure electric vehicles in the automobile market, the problem of low cost performance has gradually emerged. In order to solve the problem of low cost performance of pure electric vehicles, a dynamic parameter matching model based on genetic algorithm (GA) is proposed. Using Matlab simulation, the performance comparison experiment was carried out with the transmission speed ratio optimized by GA, by weighting method with non-optimized. The results show that the energy consumption under the condition of the transmission speed ratio optimized by the GA is 1.972 kWh, which is better than the energy consumption optimized by the weighted method and the energy consumption before optimization. The proposed model has shown that the consumption was decreased by 2.6% when compared with the non-optimised model. [ABSTRACT FROM AUTHOR]

To obtain a picking and planting integrated transplanting mechanism (PITM) with ideal trajectory shape, reasonable operating attitude, and compact structure for vegetable pot seedling transplanting, a symmetrical structural PITM composed of two planetary carriers and driven by a cam–noncircular gear combination mechanism was proposed in this paper. In accordance with the requirements of transplanting agronomy, the shape of the motion trajectory and the attitude of the end tip of the clamping claw at several specific positions (the starting and end points of picking seedling, the starting point of pushing seedling, and a special point on the return segment) were planned. To make the clamping claws of PITM pass through a set of prescribed positions, the mechanism was simplified to an open-chain 3R mechanism. An accurate four-position-based method for solving the open-chain mechanism model was adopted to obtain the curves of its fixed hinge point (central point) and dynamic hinge point (circle point). The ratio of adjacent bars’ lengths was analyzed to determine the feasible interval of the central and circle point curves and the reasonable link length. A desired closed transplanting trajectory that goes through the given points and the corresponding transmission ratio model of the open-chain mechanism was established. After the transmission ratio of each stage of gear and cam pairs was calculated and distributed, the prototype of PITM was designed and manufactured. Lastly, the effectiveness and feasibility of the design were verified through a preliminary experiment of the prototype. [ABSTRACT FROM AUTHOR]

Extending the maximum driving distance of an electric vehicle would be beneficial given these vehicles' long charging time and limited battery capacity and to improve electricity consumption. Research on the optimal development of the powertrain is essential because the efficiency of an electric motor varies according to the operating point. In this study, we developed a simulation analysis model with a continuously variable transmission. based on the commercial electric vehicle (Company B) model and using actual vehicle driving data supplied by the Argonne National Laboratory. The shift pattern of the continuously variable transmission was then optimized by considering the change in the operating point, constant motor output area, and transmission response speed. In addition, a performance comparison was made using the model with a single reducer. The results obtained by this study showed that electronic economy improved by approximately 5% when the continuously variable transmission was applied through the combined driving simulation. Furthermore, the time taken to accelerate 0–100 km/h and 80–120 km/h reduced by 15% and 6%, respectively. The maximum driving distance on a single charge improved by 7 km. It was confirmed that the driving performance of an EV with continuously variable transmission could be improved by downsizing the electric motor to reduce manufacturing costs. [ABSTRACT FROM AUTHOR]

At present，robot joint reducers are all constant transmission ratio，which makes it difficult for the motor to reach peak efficiency. Based on the nested structure，a compact continuously variable transmission （CVT） for robots is proposed，which can effectively increase the power usage of the motor by changing the transmission ratio in real time. Firstly，the mechanism of variable speed transmission is studied to obtain the relationship between transmission ratio and the ratio of planetary gear to sun gear radius，and the nested structure and the axial movement system of planetary gear and sun gear plate are designed. Secondly，the mathematical models of envelope angle on planetary and sun gear，transmission ratio，and radial movement of metal belt are deduced. Based on the multi-rigid-body dynamics simulation software，the output speed of the CVT is verified to show that the forward and reverse deviations of the transmission are 1.89% and 3.87% respectively. Finally，the principle prototype of the CVT is manufactured and the torque experiment platform is built，and the output torque is set to a specific value to test the corresponding input torque. The experiment shows that the test value is basically the same as the theoretical value，and the average transmission efficiency is 72.1%，which indirectly verifies the correctness of the theoretical derivation.

Based on the lever method， the possible connection schemes are obtained via matching the components of leverage node of double row parallel planetary gear mechanism （PGM）. A layout scheme with less linking elements and more gears is achieved by analyzing the arrangement of engine， motor and linking elements. According to the gear ratio range of existing double row parallel PGM transmissions， the PGM connection scheme is screened， and finally 17 configurations of SMT are obtained. Arbitrary selected a configuration of SMT and topologized， the operation mode and power flow of the configuration of SMT are analyzed. It is obtained that not only can it realize engine driving， motor driving， hybrid driving， driving power generation， braking power generation and parking power generation working modes， but also is no cycle power in each working mode.

Introduction. Russia has a large spatial disunity of settlements and other objects. Therefore, it is irrational to use low-productivity technical means of cyclical action in the construction of roads. To increase the pace of road construction, improve quality, reduce energy costs for road construction, where relief allows, it is economically feasible to use a set of units of continuous action. Continuous action units, moving one after another, will consistently perform a set of works, carrying out the full construction of the road by flow method. The complex should have a continuous action unit to form a underlying layer. To create complex units, their theoretical justification is necessary. In order to determine the geometric and dynamic parameters of the loading part of the unit to form the underlying layer, the process of moving the bucket filled with soil before it is unloaded is considered.The method of research. Based on the constructive layout of the loading part of the unit, the process of moving the bucket filled with soil before it is unloaded is divided into the stages: vertical ascent, moving in the direction of the leading star of the upper drive, two phases of the bucket rotation on the leading stars of the upper drive, moving from the moment of the end of the turn on the leading star of the upper drive to the start of the turn on the lower turn. When the bucket moves vertically up, the ground is no for dumped. Graphically, this angle of the bucket is chosen when it moves in the direction of the leading star of the upper drive, at which the ground will not fall out of the bucket. Two phases of the bucket rotation on the leading stars of the upper drive and moving the bucket from the moment of the end of the turn on the leading star of the upper drive to the moment of the turn on the lower turning roller are considered. The necessary parameters dependencies have been deduced.Results. Based on the developed methodology, the geometric and dynamic parameters of the loading part of the unit are defined. In particular, the torque of the top drive, the angular velocity of the drive sprockets, the power required for the top drive, the transmission ratio from the hydraulic motor to the sprockets are calculated. Based on the power transferred, a hydromotor was selected for the upper drive of the unit.Conclusion. The calculations reveal the maximum traction force of all buckets during their travel to discharge the soil, the torque of the top drive, the angular velocity of the top drive sprockets and the power required for the top drive. It is advisable to use for the upper drive of the unit gerotor hydromotor MT-160 and two-stage planetary gearbox. The calculations made it possible to develop the design of the elements of the loading part of the continuous action unit to form the underlying layer of roads.

Non-circular helical gears, having the advantages of cams and cylindrical gears, are widely used on various occasions, whose precision machining has always been a research focus. With the accuracy requirements increasing of non-circular gears, upgrading non-circular gear hobbing models is more and more important. This paper takes the non-circular helical gears hobbing with moving axis as the research object, and establishes the ellipse standard system for high-order non-circular gears, and derives the linkage mathematical model for machining helical non-circular gears with hobbing cutters. In this paper, a preliminary design for the processing of non-circular gear hobbing is carried out. [ABSTRACT FROM AUTHOR]

This paper introduces a new two-speed planetary gear automatic transmission using an electronically controlled wedge clutch. In order to verify the feasibility of using this transmission in pure electric vehicles, the influencing factors of the two-speed transmission due to the increase in mass and the reduction in transmission efficiency are introduced. The vehicle simulation model was established on the MATLAB/Simulink platform, and the dynamic programming method was used to optimize the transmission ratio and shifting law. The simulation results show that the use of a two-speed automatic transmission can effectively improve the economic performance and dynamic performance of battery electric vehicles. [ABSTRACT FROM AUTHOR]

A two-carrier planetary gear train (PGT) configuration, named S13WN, was developed for a specific application with a negative transmission ratio in the interval between -20 and -21. 72 valid combinations of component PGTs ideal torque ratios have been developed for this configuration, from which kinematically feasible combinations providing minimal dimensions and maximum efficiency within the required interval have been selected. The minimal dimensions of the PGT were achieved with a cylindrical case shape, i.e., with the ratio of the ring gears reference diameters close to unity. Nine other PGT configurations have been synthesized for the same transmission ratio, and their design parameters optimized. The two solutions that offer the most improvements over S13WN have been developed into design concepts. [ABSTRACT FROM AUTHOR]

Extending the maximum driving distance of an electric vehicle would be beneficial given these vehicles’ long charging time and limited battery capacity and to improve electricity consumption. Research on the optimal development of the powertrain is essential because the efficiency of an electric motor varies according to the operating point. In this study, we developed a simulation analysis model with a continuously variable transmission. based on the commercial electric vehicle (Company B) model and using actual vehicle driving data supplied by the Argonne National Laboratory. The shift pattern of the continuously variable transmission was then optimized by considering the change in the operating point, constant motor output area, and transmission response speed. In addition, a performance comparison was made using the model with a single reducer. The results obtained by this study showed that electronic economy improved by approximately 5% when the continuously variable transmission was applied through the combined driving simulation. Furthermore, the time taken to accelerate 0–100 km/h and 80–120 km/h reduced by 15% and 6%, respectively. The maximum driving distance on a single charge improved by 7 km. It was confirmed that the driving performance of an EV with continuously variable transmission could be improved by downsizing the electric motor to reduce manufacturing costs.

The paper presents the results of the experimental researches performed on a double harmonic transmission, regarding the determination of the kinematic precision of positioning of the respective transmission. The experimental investigations aimed to study the influence of the variation of the torsion moment from the output shaft of the double harmonic transmission and of the reversing of the direction of rotation of the input shaft on the transmission ratio and of the kinematic precision of the positioning of the transmission. The experimental results have shown that the double harmonic transmission, with the short flexible toothed wheel, has a kinematic precision of positioning higher than that known from the simple radial harmonic transmissions.

Abstract Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent transmission, and a concave and convex locking arc device, has a large rigid impact. To solve these problems, according to the design requirements for a dryland plug seedling transplanting mechanism, a rotary seedling pick-up mechanism of a planetary gear train with combined non-circular gear transmission of incomplete eccentric circular and non-circular gears was proposed. This has the characteristics of two-times greater fluctuation of the transmission ratio in a cycle, and can achieve a non-uniform continuous drive. Through analysis of the working principle of the seedling pick-up mechanism, its kinematics model was established. The human–computer interaction optimization method and self-developed computer-aided analysis and optimization software were used to obtain a set of parameters that satisfy the operation requirements of the seedling pick-up mechanism. According to the optimized parameters, the structure of the seedling pick-up mechanism was designed, a virtual prototype of the mechanism was created, and a physical prototype was manufactured. A virtual motion simulation of the mechanism was performed, high-speed photographic kinematics tests were conducted, and the kinematic properties of the physical prototype were investigated, whereby the correctness of the theoretical model and the optimized design of the mechanism were verified. Further, laboratory seedling pick-up tests were conducted. The success ratio of seedling pick-up was 93.8% when the seedling pick-up efficiency of the mechanism was 60 plants per minute per row, indicating that the mechanism has a high efficiency and success ratio for seedling pick-up and can be applied to a dryland plug seedling transplanter.

There are many types of planetary gear trains， and each one corresponds to a transmission ratio calculation formula， which makes great difficulties in the comprehensive research of planetary gear trains and the development of general design software. According to the structural diagram of the planetary gear train， the corresponding adjacency matrix is written. Then， the basic loop of the train is searched from the adjacency matrix to construct the basic loop matrix. Finally， the basic loop matrix is transformed into the coefficient matrix of the equation of motion. And use MATLAB to automate this algorithm and solve the equation of motion to obtain the gear ratio of the planetary gear train.

The difference between the planetary differential mechanism and the planetary closed differential mechanism is analyzed by examples of planetary transmission mechanism. The evolution process of RV reducer from one tooth differential cycloid needle wheel reducer is analyzed，the concept that the crank shaft is a negative 1 tooth sun wheel in a tooth differential meshing drive is proposed and the transmission ratio equivalent calculation is carried out. The power flow diagram of RV reducer is equivalent，and the transmission power distribution ratio formula of each branch is obtained，and the essence of planetary closed differential motion of RV reducer is revealed. This theoretical analysis is instructive for the forward design of the RV reducer.

The transmission of vibration waves in specific frequency bands can be suppressed by the local resonance and the multi-layer transmission structure. A composite non-periodic isolator containing a local resonance structure is proposed in this paper. The transmission performance of vibration waves is studied using the modal displacement, and the main vibration control frequency band is picked up for vibration wave transmission. Meanwhile, the total power distribution, frequency quality loss factor and total power loss density are calculated in main frequency band. Further, the energy transmission and loss performance of vibration waves are studied in the composite non-periodic isolator. The transmission ratio of the vibration wave is also discussed, the evolution of the vibration transmission ratio is compared in each metal frame of the composite non-periodic isolator, and the vibration isolation performance is evaluated. Research shows that the vibration isolation energy can be effectively increased and the vibration isolation performance can be effectively improved in the proposed composite non-periodic isolator. [ABSTRACT FROM AUTHOR]

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is considered the kinematic schema of a complex planetary mechanism, which is achieved through aggregating of three planetary units with cylindrical gearings, from the make-up of automatic transmissions used to the automotives. Known the kinematic conditions, specify those five speed stages, in paper is presented a method of synthesis of type structural -- topological and kinematical following the calculation analytical expressions of the transmission functions input -- output in each gear. [ABSTRACT FROM AUTHOR]