Variable Transmission Research Articles

Design and Testing of a Crawler Chassis for Brush-Roller Cotton Harvesters

In China’s Yangtze River and Yellow River basin cotton-growing regions, the complex terrain, scattered planting areas, and poor adaptability of the existing machinery have led to a mechanized cotton harvesting rate of less than 10%. To address this issue, we designed a crawler chassis for a brush-roller cotton harvester. It is specifically tailored to meet the 76 cm row spacing agronomic requirement. We also conducted a theoretical analysis of the power transmission system for the crawler chassis. Initially, we considered the terrain characteristics of China’s inland cotton-growing regions and the current cotton agronomy practices. Based on these, we selected and designed the power system and chassis; then, a finite element static analysis was carried out on the chassis frame to ensure safety during operation; finally, field tests on the harvester’s operability, stability, and speed were carried out. The results show that the inverted trapezoidal crawler walking device, combined with a hydraulic continuously variable transmission and rear-drive design, enhances the crawler’s passability. The crawler parameters included a ground contact length of 1650 mm, a maximum ground clearance of 270 mm, a maximum operating speed of 6.1 km/h, and an actual turning radius of 2300 mm. The maximum deformation of the frame was 2.198 mm, the deformation of the walking chassis was 1.0716 mm, the maximum equivalent stress was 216.96 MPa, and the average equivalent stress of the entire frame was 5.6356 MPa, which complies with the physical properties of the selected material, Q235. The designed cotton harvester crawler chassis features stable straight-line and steering performance. The vehicle’s speed can be adjusted based on the complexity of the terrain, with timely steering responses, minimal compaction on cotton, and reduced soil damage, meeting the requirements for mechanized harvesting in China’s inland small plots.

МОДЕЛИРОВАНИЕ ПУСКА ДВС АВТОМОБИЛЯ С БЕССТУПЕНЧАТОЙ КОРОБКОЙ ПЕРЕДАЧ

The aim of the work is to build a computer dynamic model of moving internal combustion engine parts and a continu-ously variable transmission to determine the starting characteristics of the internal combustion engine. The paper objective is to define the characteristics of moving parts of the internal combustion engine and continuously variable transmission when starting the internal combustion engine with an electric starter. The research method is computer modelling of moving internal combustion engine and transmission parts when starting with an electric starter. The novelty of the work lies in building a computer model of moving parts of an internal combustion engine and a contin-uously variable transmission, connected by a torsional vibration damper, considering changes in friction parameters. The results are in developing a computer model to determine the starting characteristics of a four-cylinder in-line four-stroke internal combustion engine with spark ignition and a continuously variable multitronic® 01J transmis-sion. To check the computer model adequacy, the author uses the values of the average friction pressure in accord-ance with GOST R 54120-2010 and empirical data on the unevenness of the angular velocity of the crankshaft. Simu-lating a four-stage start of an internal combustion engine shows that opening the cylinder valves at the 1st stage in-creases the angular velocity of the crankshaft by 4%. Temporary switching on the reverse clutch for 1.4 s reduces the amplitude of angular oscillations of the solar shaft by 2.22 times, eliminates the beating of the contacting gearbox teeth, but slows down the crankshaft speed by 7.6%. After the reverse clutch is turned off, periodic changes in the an-gular velocity of gearbox parts occur.

Output speed control for hydro-mechanical continuously variable transmission of tractor.

In order to improve the speed stability of tractors equipped with hydro-mechanical continuously variable transmission (HMCVT) during field operations, the speed regulation characteristics, torque characteristics, and power diversion characteristics of HMCVT are analyzed. And a comprehensive control strategy for HMCVT output speed is proposed by analyzing the factors affecting the fluctuation of output speed, which combines engine speed control and displacement ratio control of hydraulic speed control system. This strategy adopts fuzzy control to regulate the engine speed to maintain the stability of engine operation. Moreover, adopting feed forward compensation control for speed compensation enhances the anti-interference ability of the hydraulic speed control system. And combined with model predictive control, adjust the swash plate swing angle of the variable pump to reduce the fluctuation of HMCVT output speed. By establishing joint simulation model, the effectiveness of the control strategy was verified using tractor acceleration mode and step load disturbance mode. The results show that the strategy can reduce the fluctuation rate of engine speed and impact degree, shorten the adjustment time, and improve the stability of tractor operating speed.

Research on the Energy Management Strategy of a Hybrid Tractor OS-ECVT Based on a Dynamic Programming Algorithm

The multi-degree-of-freedom characteristics of the planetary gear electronic continuously variable transmission (ECVT) configuration in series-parallel hybrid tractors impose more complex requirements for energy management strategies under variable load conditions. For a high-power hybrid tractor, this paper takes the hybrid tractor output-split (OS)-ECVT configuration as the research object and describes the principles of stepless transmission and power-splitting within the configuration. In order to improve the fuel economy of high-power hybrid tractors and the running status of power components, an energy management strategy focused on ploughing conditions based on the Bellman minimum dynamic programming (DP) algorithm is proposed in this paper. Second, equivalent fuel consumption is selected as the performance index for energy-saving control, and the solving principle of the energy management strategy based on the dynamic programming algorithm is established to facilitate the resolution process of the energy management strategy. Finally, the energy-saving control simulation is completed under ploughing conditions. The results show that compared with the energy management strategy based on the optimal operating line (OOL), the energy management strategy based on DP fully utilizes the benefits of low-cost electric energy and enables the hybrid power system to have a wider range of stepless transmission performance. In addition, the hybrid power system has the advantages of enhanced decoupling of speed and torque, higher efficiency, and more economical secondary energy conversion. As a result, the whole machine has enhanced power-split performance, greatly improving the running conditions of the power components. The equivalent fuel consumption values of the energy management strategies based on DP and OOL are about 3.1238 L and 4.2713 L, respectively. The equivalent fuel consumption based on DP is reduced by about 26.87%, which effectively improves the fuel efficiency of hybrid tractors.

Understanding Climate Variability and Malaria Transmission in West Africa: Case Studies, Regional Insights, and Future Directions

Climate variability plays a crucial role in malaria transmission in West Africa. Variable temperature, rainfall, and humidity patterns in diverse climatic zones, such as tropical rainforests and semi-arid regions, significantly influence mosquito breeding sites and transmission rates. Tropical rainforests experience high transmission rates due to consistent rainfall and humidity, while savanna regions experience seasonal peaks. Semi-arid regions with limited rainfall and extreme temperatures show lower but variable transmission rates. Temperature fluctuations affect the development and survival of Anopheles mosquitoes and malaria parasites. Rising temperatures can extend transmission seasons and spread the disease to unaffected areas. Rainfall patterns affect breeding site availability, with heavy rains increasing breeding sites and droughts reducing mosquito populations. Humidity influences mosquito survival and parasite development. Extreme weather events, such as cyclones and floods, exacerbate malaria transmission by increasing breeding sites and damaging infrastructure. Socioeconomic factors, including urbanization, land use changes, and economic instability, also interact with climate variability to impact malaria dynamics. The review highlights the need for integrated malaria control strategies that incorporate climate considerations, including enhanced surveillance, climate-resilient infrastructure, and community engagement. Future research should address knowledge gaps regarding the interaction between climate variables and malaria transmission, and the socioeconomic impacts of climate change on malaria dynamics. By tailoring control strategies to specific climatic and socio-economic contexts, stakeholders can better manage malaria risks and improve health outcomes across West Africa. Keywords: Climate, Variability, Malaria, Transmission, West Africa, Case Studies.

Analysing the possibility of using a hydraulic transmission with motor wheels for the nomad at off-roader

Problem. The creation of transport vehicles for operation in difficult road conditions requires solving a complex of problems related to the fulfilment of the necessary requirements for speed and traction characteristics, in particular, shifting modes, overcoming climbs, manoeuvrability and increased speed with its stepless change, anti-skid properties. Such requirements are achieved thanks to constructive solutions in transmissions of various types. Goal. The aim is an attempt to create a full-flow continuously variable transmission with hydrostatic transmission and motor-wheels instead of a step-mechanical one to improve the technical characteristics of the all-terrain vehicle and the technological possibilities of manufacturing the transmission by the block method when using standard components. Methodology. Based on the analysis of the technical characteristics of the analogue all-terrain vehicle with a mechanical multi-gear transmission and a review of achievements in modern hydrostatic transmission with hydraulic motor-wheels, static calculations were carried out to assess the possibility of creating a stepless full-flow hydro volume transmission and building its hydraulic schematic diagram. Calculations are based on mathematical models created on the basis of the laws of mechanics and hydraulics. The results. According to the results of the calculations, it has been shown that it is fundamentally possible to create a stepless hydrostatic transmission for an all-terrain vehicle with the specified traction and speed characteristics. Further research is proposed on the analysis of the dynamics of the hydrostatic transmission of the all-terrain vehicle and the creation of a corresponding experimental model of the vehicle. Originality. For the analogue all-terrain vehicle, the hydraulic motor-wheels required for the working volume were selected, which provide the parameters of traction and speed characteristics and allow creating an original transmission without the use of reducers and gearboxes. Practical meaning. The obtained results are planned to be considered as recommended for carrying out a functional and cost analysis in the design and determination of technological possibilities in the manufacture of a hydrostatic transmission of an all-terrain vehicle. It is also proposed to consider the method of calculating the hydrostatic transmission of an all-terrain vehicle in the educational process for master's students of industrial mechanical engineering when studying the disciplines related to the design of hydraulic drives and their tests.

Does shrinkage have an impact on urban livability? An empirical analysis from Northeast China

Urban shrinkage has emerged as a global socioeconomic development issue, presenting new challenges for countries in advancing the construction of livable cities. To investigate whether urban shrinkage has an impact on urban livability (UL), along with its underlying mechanisms and transmission paths, this study employed comparative inductive analysis and took Northeast China as a case for theoretical discussion and empirical validation. The results indicated that: (1) Shrinkage did have an impact on UL, which was dominated by negative effects and supplemented by positive effects. Furthermore, it exhibited characteristics of phased and dimensional heterogeneity, with significant spatial differentiation. (2) The impact of shrinkage on UL was essentially a comprehensive result of the interplay between the positive and negative effects arising from changes in urban development capacity and per capita occupancy caused by shrinkage. This process involved both variable transmission paths and stock transmission paths, jointly explaining the positive and negative shrinkage effects. This study provides a new perspective on rational cognition for coping with shrinkage effects and their generative logic, as well as theoretical insights for other countries around the world to optimize UL in shrinkage scenarios.

Continuously Variable Transmission and Stiffness Actuator Based on Actively Variable Four-Bar Linkage for Highly Dynamic Robot Systems

Continuously Variable Transmission and Stiffness Actuator Based on Actively Variable Four-Bar Linkage for Highly Dynamic Robot Systems

Research on the application of artificial intelligence tools to predict the operating temperature and pressure of the pipeline transportation system at the Hai Thach - Moc Tinh field

The observation of operating parameters for the single-phase or multi-phase flows of oil and gas pipelines always plays an important role and prerequisite in daily operation. The inlet and outlet parameters of the pipeline such as pressure and temperature will greatly affect the efficiency of the production and transportation process of fields. These parameters are very important. It must be required to observe carefully and strictly. In fact, pressure and temperature signal gauges will always be set up at the inlet and outlet of the pipeline for continuously variable transmission of the signal to the central control room, then the operator can observe regularly. Alarms will be triggered when the signal goes out of the setting operation area. However, the operational parameters transmitted from this gauge are only available after the actual fluid flow passes through the pipeline. This will limit when the operator needs to apply calculation methods to pre-predict the flow regime, and operating parameters of the fluid in the pipeline when fluid flows has not passed through the pipeline. From that approach, the paper presents the result of research on the application of machine learning algorithms (ML) to build models to predict operating conditions of three-phase flows in the pipeline at Hai Thach- Moc Tinh field based on input parameters such as the open of wellhead flow control valve of wells located in wellhead platform WHP-MT1, WHP-HT1, and the commercial gas volume. The results of the research show that the ML calculation method gives the result which is only +/-2 barg/20C difference compared to the field data obtained from pressure (HT1-PT-0911) and temperature (HT1-TI-0911) signals set up at the outlet of the transportation pipeline at the Hai Thach-Moc Tinh field.

10 kV nanosecond pulse generator with high voltage gain and reduced switches

AbstractIn the article, a new type boost high‐voltage nanosecond pulse generator is proposed. The distributed inductance of the transmission line is utilised as the energy storage unit and cooperated with the variable impedance transmission line transformer to generate nanosecond pulses with extremely high‐voltage gain. What’s more, the isolation effect caused by the transmission line time delay is applied to achieve modular stacking. The demand for charging power supply can be greatly reduced, and few switches are used. Finally, the topological principle is verified by experiments, and a prototype of the five‐stage stacking prototype is built. With the charging voltage of 28 V, the generator can output pulse with a voltage amplitude of 10 kV and pulse width of 12 ns whose voltage gain is up to 357 times.

A Robotic Finger With a 4-Bar Linkage-Based Compact and Continuously Variable Active Transmission

A Robotic Finger With a 4-Bar Linkage-Based Compact and Continuously Variable Active Transmission

Performance Enhancement of Power-Cycle Hydro- Mechanical Transmission with Accumulator

Abstract In this study, a new power-cycling hydro-mechanical continuously variable transmission system (PCHMCVT) with energy recovery using an accumulator is proposed. The simulation of the basic characteristics of PCHMCVT is done using Simulink/Simscape and these characteristics have been validated with previous studies. The model is then used to examine the effect of adding energy recovery using an accumulator on the output power and the efficiency. The system is simulated on a driving cycle and the output velocity is investigated. The hydro-mechanical transmission system works in two modes of operation to improve the driving range. The effect of the accumulator is investigated in both of these modes. A comparison between the performance of the system with and without an accumulator is made to show the effect of the accumulator on the system and energy recovery. The results indicate that the energy recovery system can be utilized in both the driving and braking of the vehicle. The addition of an accumulator has improved the efficiency of the system by 8.1% and the power consumption of the engine has been reduced by 20.8%.

POLarizer-FENestration (POLFEN) a novel concept of a glazing technology to modulate daylighting and glare in buildings

A conceptual new window/glazing technology called POLarizer-FENestration (POLFEN) is presented. In 1935, Edwin Land's pioneering work on polarizers successfully developed a sheet polarizer that was used in various applications. Subsequently, polarizers were employed in windows to modulate daylight and reduce associated glare. Early prototype windows were circular in shape so that the polarizing filter could be rotated to modulate the daylight. However, compared to rectangular-shaped windows that are ubiquitous, circular windows are rare in buildings. Therefore, a new window/glazing technology, discussed in this paper, was developed that utilizes a polarizing film in a conventional rectangular or square window, arranged in the form of strips or a checker-grid over the window panes to modulate daylighting levels and control glare. In this new research, a working prototype of the glazing technology is developed and demonstrated including simulations using the Radiance daylighting simulation software. In the current work, two types of measurements were taken: photographs of the indoor luminous environment and illumination levels (Lux) at selective points on the work-plane both in a physical prototype as well as in the simulation model under two sky conditions: CIE clear sky with sun, and overcast sky. The results indicate that the new glazing technology resulting from this concept can effectively modulate daylighting levels, minimized associated glare to an acceptable level while maintaining a view to the outdoor environment. The technology can be classified as Variable Transmission Glazing (VTG), similar to Electrochromic (EC) glazing since it also offers a dynamic modulation of solar optical properties (Tvis).

Pengaruh Perubahan Massa Roller dan Konstanta Pegas Sistem Cvt Terhadap Daya dan Torsi Pada Sepeda Motor 109 Cc

The development of the automotive industry is now experiencing a very rapid increase in the type of motorcycle. One of them is a motorcycle with automatic transmission or automatic motorcycle or CVT (Continously Variable Transmission). Matic motorcycle users often experience a lack of performance when used on daily trips. The mass of CVT rollers and springs is the main factor in the lack of performance of the matic motorcycle which is less efficient for its users. This research was conducted to determine the effect of increasing power and torque on motorcycles that are now declining in performance. The method used in this research is experimentation. Tests were carried out using a dynamometer tool to determine the comparison of the results of the variables carried out and compared to obtain maximum power and torque. The data obtained will be analyzed using statistical methods to evaluate the relationship between changes in roller mass and spring constant to power and torque. The results showed that the maximum power generated was at a roller variation of 11 grams and a spring constant of 33.78 N/cm of 7.19 HP at 6500 rpm engine speed. While the maximum torque is generated from the variation of roller 13 grams and spring 28.83 N / cm of 8.00 Nm at 6000 rpm engine speed.

Equivalent consumption minimization strategy based on global optimization of equivalent factor for hybrid tractor

Due to the increase in emission requirements for non-road vehicles in many countries and the reduction of agricultural personnel, tractors are developing towards high horsepower and electrification. According to the working conditions of high-horsepower tractors, a hydromechanical continuously variable transmission (HMCVT) is designed for hybrid tractors. Taking a tractor equipped with this transmission as the research object, an equivalent factor global optimization model was established and a genetic algorithm was used to optimize the equivalent factor S offline to obtain the optimal equivalent factor of the tractor under different operating mileage and the initial state of charge (SOC) of battery. By using the optimized equivalent factor, the tractor can be in the charge depleting (CD) mode for a longer time on the premise of making full use of the energy in the battery, so as to improve the auxiliary ability of the motor in the whole operation cycle to reduce the fuel consumption of the tractor. The effectiveness of the control strategy is verified by MATLAB/Simulink and hardware in the loop (HIL) tests, and the fuel economy of tractors is improved by 2.939% and 3.909% respectively in the two tests.

Continuously Variable Two-Flow Hydrostatic-Mechanical Transmission of Crawler Tractor

The paper proposes an original design of a continuously variable two-flow hydrostatic-mechanical transmission, which ensures division of the power flow along the sides of the crawler tractor. To ensure stability of rectilinear motion, their volumetric and mechanical efficiency, the maximum pressure of the working fluid in the hydraulic transmission, the maximum speed and torque on the shaft of the hydraulic motor. The parameters of an unregulated hydraulic motor, an adjust-table pump and mechanical transmission elements are selected. A mathematical model of the rectilinear motion of a caterpillar tractor with a continuously variable hydrostatic-mechanical transmission has been developed, taking into account the weight of the tractor, the parameters of the running system, the characteristics of the internal combustion engine, the parameters and efficiency of hydraulic machines, gearboxes, range and transfer boxes, planetary gear and allowing to determine the efficiency of individual branches and the entire transmission, carry out traction calculations of the tractor. A calculation program has been developed that implements the mathematical model. The parameters of the dual-flow transmission are selected so that most of the torque is transmitted through the mechanical branch and the transmission has a fairly high efficiency value. The maximum value of tractor traction efficiency is realized in the second and third ranges, which are designed to perform basic tillage operations.

A Novel Continuously Variable Transmission with Circumferentially Arranged Disks (CAD CVT)

This paper presents a novel Continuous Variable Transmission (CVT) design. CVT is highly beneficial for actuators with rotary output as it can improve the energy efficiency of the actuators by providing an optimum transmission ratio. This property of CVT is highly beneficial for fossil-fuel-based vehicles, electric vehicles, wind turbines, industrial robots, etc. With the exception of Spherical CVT and DH CVT, all known CVTs like push belt CVTs, toroidal CVTs, Milner CVTs, etc., require additional gear sets and clutches for direction reversal and neutral gear ratio. However, Spherical CVT and DH CVT have low torque capacity due to a single traction point constraint. Foregoing in view, a new CVT named CAD CVT has been developed. The paper presents the design conception, the operating principle, the transmission ratio, the torque capacity, frictional losses, and experimental verification of the basic functionality by manufacturing a Proof of Concept (PoC). The proposed CVT is the only CVT capable of independent direction reversal and high torque capacity as it can transmit torque through multiple traction points. The new CVT will significantly impact high-torque applications in different engineering applications, especially land transport consisting of heavy vehicles like trucks, buses, and trailers.

STUDI KASUS PERHITUNGAN TEGANGAN PADA FLAT BELT DALAM APLIKASI MESIN IHR

The Continuously Variable Transmission (CVT) automatic transmission system is a power transmission component widely used in various industrial sectors such as manufacturing, paper, automotive, and electric power. The decision to use this transmission is made due to its ease of maintenance, affordability, and its ability to operate within various power and speed ranges. Key components of the CVT automatic transmission system include flat belts, pulleys, rollers, CVT springs, CVT clutch linings, and clutch clutches. Calculation analysis will be conducted to determine the maximum stress of the flat belt, identify the material of the flat belt, and calculate the lifespan of the flat belt using the IHR machine. The results of the calculation show that the tight side stress is 383.3639 N, the loose side stress is 64.867 N, and the belt material stress is 3.1 N/mm2. These optimal stress and material stress values are deemed suitable for use.

Stepless Transmission Optimization for Green Micromobility

Small, electrified vehicles are becoming possible for urban environmental mobility due to their environmental performance, including zero-emission driving. Vehicles of this type use electric motors as sources of mechanical energy. Today, two types of transmission are most used in electrical micromobility vehicles (skateboards, scooters, tricycles, quadricycles, mopeds, motorcycles, go-karts, etc.): chain transmission and belt transmission. This transmission types provides a constant gear ratio that can only compromise between the maximum speed and the starting torque values, thus reducing the usage efficiency of the engine. This reduces vehicle manufacturers’ choice of less powerful drive and control elements, as well as balancing performance and efficiency at low and high speeds as well as on terrain.A novel design of a continuously variable transmission (CVT) for an electric go-kart is presented in this paper. The CVT consists of an inertial driving pulley mounted on an electric motor shaft, a timing V-belt, a gear wheel on the drive axle and 2 pressure rolls, which are moved by a servo motor for tensioning the V-belt. Gear ratio of a transmission can change seamlessly in the range of 1.5 - 2.2. The CVT has been tested under real conditions. The top speed of the electric go-kart with the given CVT and motor power 24.7 kW is 133km/h; time to accelerate to the top speed is 25 s. Total efficiency of the transmission (motor shaft, CVT, drive axle and wheels) is 65-72 % now, but there exist a lot of possibilities to improve it in the future. The conditions under which the novel CVT has an advantage over belt and chain transmissions with constant gear ratios have been studied. The developed mathematical model, the method for determination its constants, the algorithm for numerical calculations and the optimization criterion makes it possible to determine the optimal gear ratio for a vehicle with various CVT (not only belt) at any point in time in different racing modes. The model has been proved experimentally during acceleration and deceleration tests of the go-kart; it describes precisely the motion of the go-kart within the speed measurement error.The developed solution is applicable in urban micromobility. An optimized and stable transmission system focused on energy efficiency, resource saving, using less powerful drive and zero-emission.

Optimal Scheduling of Mobile Energy Storage Capable of Variable Speed Energy Transmission

Optimal Scheduling of Mobile Energy Storage Capable of Variable Speed Energy Transmission