Continuously Variable Transmission Research Articles

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.

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.

Decoupling Analysis of Brushless Dual-Mechanical-Port Dual- Electrical-Port Machines

The brushless dual-mechanical-port dual-electrical-port (BLDD) machine has emerged as a promising alternative to the traditional mechanical continuously variable transmission (CVT), due to its gearless and brushless design. In BLDD machines, two sets of windings are placed in the same stator, and care must be taken to avoid strong coupling that may deteriorate the machine performance and reliability. This paper categorizes the topologies of existing BLDD machines into five types and presents a systematic decoupling analysis from the perspective of field-modulation theory. Using the presented method, the conditions to achieve decoupled designs are concluded and the decoupling characteristics of each type of BLDD machine are identified. Besides, a simple indicator is developed to fast identify the coupling type, i.e., decoupled, low or high coupling design, of BLDD machines, enabling an efficient selection of slot-pole combinations. With the aid of finite-element analysis (FEA), the coupling degree of BLDD machines with various slot-pole combinations has been analyzed for verification. Other performances, such as torque density and PM utilization, are also compared among the five types of BLDD machines to provide a more comprehensive view of their characteristics. Finally, a prototype of a BLDD machine is manufactured and tested to validate the analysis.

Analisis Perbandingan Penggunaan Pegas CVT Racing 1000 RPM 1500 RPM 2000 RPM terhadap Performa Sepeda Motor Honda Beat 110 CC

In the era of automatic transmission or automatic transmission motorbikes, many people enjoy doing it in various circles compared to manual transmission motorbikes, these automatic transmission motorbikes are indeed fuel efficient and agile, but automatic motorbike users are not satisfied with their less optimal power, seeing the problems in The use of springs is a factor that influences the performance of automatic transmissions. The purpose of this study is to analyze one of the components of the Continuously Variable Transmission, namely the CVT spring. then compare the power and torque values to find out the comparison of the use of the three springs on the vehicle and retrieve data through the dynotest process. Tests using this dynotest tool produce the values of power, torque, and engine speed produced by the vehicle, this test uses three springs with different constant values such as 1000 Rpm, 1500 Rpm, 2000 Rpm to retrieve table and graphic data values and then compare the data to be converted into thrust and vehicle speed values. To obtain the maximum speed of the vehicle. From the experimental results, each spring produces a different transmission ratio. This results in the value of power and torque, which is produced by each different spring.

Design, Analysis and Manufacturing of Continously Variable Transmission of all Terrain Vehicle

This project focuses on the integration of Continuously Variable Transmission (CVT) technology into All-Terrain Vehicles (ATVs) to enhance their adaptability and performance. The aim is to design, analyse, and manufacture a specialized CVT system tailored to the unique requirements of ATVs. Recognizing the challenges faced by conventional transmission systems in off-road environments, the project seeks to optimize power delivery, improve acceleration, and enhance fuel efficiency through the implementation of a well-designed CVT. The project begins with a comprehensive literature review, providing insights into the existing knowledge on CVT technology and its relevance to off-road vehicles. The conceptual design phase involves generating innovative design concepts, aligning with the specific needs of ATV applications. Engineering analysis, a critical aspect of the project, utilizes simulation tools and mathematical modelling to ensure the reliability, durability, and efficiency of the proposed CVT system under diverse operating conditions.

A Duster Plug-in Hybrid Electric Vehicle with Wireless Charging System

The paper presents the GASTER Electricway 4WD concept, Plug-in Hybrid Electric Vehicle (PHEV) type, in development within the Automotive Engineering Research Centre of the University of Pitesti, aiming to create a green and versatile version of Romanian Dacia Duster. The car has been built by implementing a hybrid propulsion system with electrified rear axle. This hybrid system is PHEV, parallel type with two shafts, organized in a motorized solution E4WD (Electricway 4WD). It is composed of a thermal power train with a 1.6 litre engine fuelled with Compressed Natural Gas (CNG) and a CVT (Continuously Variable Transmission), placed in the front of the vehicle. The electric powertrain, located at the rear side of the vehicle includes an electric motor coupled with a mechanical transmission. The traction battery is Lithium-ion NMC type. The charging of the traction battery can be performed with the on board charger of by cable from a Wallbox or public station, in the Standard version, and Plug-in bidirectional or Wireless from renewable sources in the Premium version.

Pengaruh Massa Weight Roller terhadap Keausan Material dan Akselerasi Motor N-Max

The Nmax motorbike roller basically consists of 6 units which function to maintain and regulate motor acceleration found in the Roller Housing in the Continuously Variable Transmission (CVT) section which allows friction and wear to occur on the roller material. Acceleration is the level of acceleration that occurs in an object at a certain time, while material wear is the mechanical property of an object to accept loads, power and energy without causing damage. This research was carried out using a Tribometer test tool and logger pro analysis software. The results obtained show that material wear increases with increasing RPM. At 500 rpm, standard roller wear ranges from 0.107% to 0.346%, while at 1400 rpm, wear increases to range from 0.323% to 0.938%. The acceleration test results show that the standard roller with a mass of 13 grams has the lowest acceleration performance, with the lowest value occurring in test II at 1.26 m/s². Meanwhile, the 9 gram roller has the highest average acceleration of 4.82 m/s².

Common transmission theory and wide application

Gear and belts/chains are the most common solution for modern mechanical devices. The allowable stress and gear ratio are two of the main factors that decide the performance of the ear section for transmission. The allowable stress can be calculated by bending stress and contact stress from design criteria. The performance of the belt solution is decided by the belt/chain material, center distance and the belt length. The allowable strength of the belt/chain solution is strongly related to the materials selected. With the current study of belts and gears, the related factors could be calculated to design the optimum shape and material. Dual clutch transmission (DCT) and continuously variable transmission (CVT) are two widely applied transmissions with gear and belt/chain solutions that are introduced in the research. The advantages of DCT could be the reliability and high transmission efficiency of the gear solution and the space and energy efficiency of belt/chain structure advantages of the CVT. Both DCT and CVT could be applied in different conditions to maximize the specific performance.

A Continuously Variable Transmission-Based Variable Stiffness Actuator for pHRI: Design Optimization and Performance Verification

Abstract Physical human–robot interfaces (pHRIs) enabled the robots to work alongside the human workers complying with the regulations set for physical human–robot interaction systems. A variety of actuation systems named variable stiffness/impedance actuators (VSAs) are configured to be used in these systems’ design. Recently, we introduced a new continuously variable transmission (CVT) mechanism as an alternative solution in configuring VSAs for pHRI. The optimization of this CVT has significant importance to enhance its application area and to detect the limitations of the system. Thus, in this paper, we present a design optimization approach (an adjustment strategy) for this system based on the design goals, desired force, and minimization of the size of the system. To implement such design goals, the static force analysis of the CVT is performed and validated. Furthermore, the fabrication of the optimized prototype is presented, and the experimental verification is performed considering the requirements of VSAs: independent position and stiffness variation, and shock absorbing. Finally, the system is calibrated to display 6 N continuous output force throughout its transmission variation range.

Retracted: Hybrid Recurrent Laguerre‐Orthogonal‐Polynomial NN Control System Applied in V‐Belt Continuously Variable Transmission System Using Particle Swarm Optimization

Retracted: Hybrid Recurrent Laguerre‐Orthogonal‐Polynomial NN Control System Applied in V‐Belt Continuously Variable Transmission System Using Particle Swarm Optimization

APPLYING REGULAR RELIEF ONTO CONICAL SURFACES OF CONTINUOUSLY VARIABLE TRANSMISSION TO ENHANCE ITS WEAR RESISTANCE

While investigating the variator transmission of vehicles, the relationship between the technological and service parameters of the working surfaces of conical disks treated by technological methods was established. The service properties are proposed to be enhanced by Regular MicroReliefs (RMRs) created on such surfaces. The optimal technological processing conditions were found, which allow retaining the greatest amount of lubricant. The causes of surface defects, formed on the working surfaces of conical disks of the Continuously Variable Transmission (CVT), are systematized and classified. The wear resistance of such surfaces is proposed to be enhanced by technological methods, in particular, by forming partially RMRs on them. Their application facilitates relaxation processes on the material near to the surface, reduces shear stresses and strains, thus preventing the formation of burrs and extending the life of the conical disks of the CVT. A novel approach for obtaining the toolpaths of the deforming element, based on the so-called “Commis–Voyageur problem” algorithms, is employed in order to research the possibilities for involving that methods in toolpath generation. Dependences between the partial RMR’s formation conditions (deforming forces and feedrate) and microgeometric quality parameters are established. The latter include surface roughness, with a partially RMR applied onto the face surfaces of the test specimen (rotary body). It is found that these microreliefs enhance the ability of oil retaining in plastically deformed traces, formed over the operational surfaces, in comparison with those, that are processed by traditional cutting methods, as turning for example.

Battery Electric Vehicles: How Many Gears? A Technical–Economic Analysis

The large majority of electric cars have a single-speed gearbox, because electrified powertrains provide maximal power across a wide operating range, and single-speed simplifies construction and reduces capital costs. Nevertheless, multi-speed transmissions have also been developed for electric cars, and some of them have recently appeared as commercial products. This paper aims to compare, through some practical examples, solutions with single-speed and dual-speed transmissions. In particular, given the very smooth driving of electric cars, for dual-speed solutions, a dual-clutch gearbox was considered. Finally, a continuously variable transmission (CVT) was also used. Different solutions were analyzed from a technical–economic point of view, based on a simulation of the vehicle under standardized driving cycles, thus evaluating the capital and running electricity costs. The obtained results show that the comparison between the two solutions is very open, and in the majority of cases, the advantages in terms of efficiency overcome the disadvantages due to the additional capital costs. For a rather low battery cost of 150 €/kWh, the total cost reduction moves from about 100–150 € up to 1500–2000 €, depending on the electricity cost, along the whole vehicle lifespan.

AGRICULTURAL MECHANIZATION EVOLUTION: the journey of mechanizing harvesters and tractors - a study focusing on CASE IH® machinery

The research presents an analysis of the evolution of agricultural mechanization, focusing on the tractors and harvesters of the brand CASE IH®. CASE IH® has a deep-rooted history in American agriculture, resulting from the merger of several pioneering companies in the early 20th century. Since then, it has played a crucial role in the global evolution of agriculture, offering high-quality equipment that has transformed agricultural work methods. The present study aims to: present the evolution of machinery in agriculture, emphasizing innovation and technology over time, and demonstrate the progression of CASE IH® brand tractors and harvesters. This research has a basic nature and adopts a qualitative approach with descriptive and exploratory objectives, using the method of narrative literature review through bibliographic research. The evolution of agricultural mechanization has had a significant impact on the productivity and efficiency of the agricultural sector. CASE IH® demonstrates its commitment to efficiency and sustainability by introducing technologies such as the Advanced Farming System (AFS) and the Continuously Variable Transmission. This research underscores the importance of understanding this evolution to envision the future potential of agriculture and the opportunities that may arise.

Research on Designing the Continuously Variable Transmission Test Bench

The continuously variable transmission (CVT) is designed to enhance the performance of the powertrain system. It helps the vehicle have better acceleration as well as improves the fuel economy. Fuel consumption in a car is directly linked to transmission efficiency, primarily influenced by the vehicle's drivetrain system. Factors affecting the transmission efficiency of transmission including belt structure, hydraulic pressure, and control technique are factors that need to be studied and improved. This study was carried out to calculate and design the mechanical, hydraulic, and electrical control systems of a CVT test bench. With the initially designed test bench simulated, it is possible to evaluate the characteristic quantities controlling the transmission ratio of the gearbox such as the pressure acting on the pulleys, the force acting on the belt, the torque at axes corresponding to different load modes vary from 2kW to 6 kW. The results of this study will be the basis for manufacturing an experimental system for in-depth studies and evaluation of the CVT such as belt slip, as well as the factors affecting transmission efficiency of CVT.

The Effectiveness of Using Continuous Variable Transmission (CVT) in 2WD Buggy Vehicles

Continuous Variable Transmission (CVT) is a transmission system that does not have gears like in manual transmission cars or conventional automatic transmission cars. CVT has the advantage of being able to maintain the proper rotational speed at any time in terms of engine efficiency by changing the speed ratio flexibly and continuously. A continuously variable transmission (CVT) is a transmission that can change steplessly through an infinite effective gear ratio between maximum and minimum. This is in contrast to other mechanical transmissions which only allow a few different gear ratios to choose. The flexibility of the CVT allows the drive shaft to maintain a constant angular speed over the output speed range. Torque is transmitted from the drive to the pulley which is driven by friction acting between the belt and pulley surfaces. Tests were carried out using a dynotest to obtain wheel rotation data and the resulting torque. The loading is given from 3 kg, 5 kg, 7 kg and 8 kg, the engine rpm used is 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm and 8000 rpm. Rear wheel rotation is inversely proportional to the load, the greater the load the rotation will decrease. Load is directly proportional to torque, the greater the load given the torque will increase. The CVT system is still effective for use as a power successor. The power that can be transmitted is still greater than 50%, namely 68%.

Investigation and Optimization of Energy Consumption for Hybrid Hydraulic Excavator with an Innovative Powertrain

This paper presents an innovative powertrain design and an energy regeneration system for hybrid hydraulic excavators to reduce energy consumption and emissions. The proposed system is designed to maximize engine efficiency and make full use of the energy gained from boom and arm retraction. The powertrain features an innovative design that incorporates a continuously variable transmission (CVT), which drives the main pump. It enables precise control of both the engine’s speed and torque, ensuring that the engine operates within the high-efficiency range. The energy regeneration system is applied to regenerate the potential energy of the boom and arm, which can be used to either charge the battery or directly supply power to the main pump. Moreover, an energy management strategy based on an equivalent consumption minimization strategy is used to distribute the power while offering maximum engine efficiency. When compared with the existing hybrid system and conventional system, the simulation results indicated that the proposed approach achieves energy-saving efficiencies of 16.9% and 77.1%, respectively, at high velocities and 22.25% and 53.5%, respectively, at medium velocities. This research signifies a promising advancement for sustainable and efficient hydraulic excavator operations.

Rotational Speed Optimization of Coaxial Compound Helicopter and Turboshaft Engine System

In order to enhance the overall performance and operational efficiency of the integrated coaxial compound helicopter and turboshaft engine system, a preliminary study on the optimal rotational speeds was implemented based on multidisciplinary integration. First, the flight mechanics model of coaxial compound helicopter and the aerothermodynamic model of turboshaft engine were developed. Then, the minimum fuel flow of the turboshaft engine was selected as the optimization objective, and an integrated optimization method of optimal rotational speeds based on the golden section method was proposed according to fixed ratio transmission (FRT) and continuously variable transmission (CVT). Finally, the effect of the optimal rotational speeds on the overall performance of the integrated system was investigated, and the variation laws of the optimal rotational speeds under different operating modes were revealed. The results indicated that the optimal rotational speeds can decrease engine fuel flow by a maximum of more than 10%, which is conducive to promoting operational economy and overall performance. Moreover, the flight conditions, helicopter weight, and engine degradation significantly affect the optimal main rotor speed.

Design principles and traction performance of a novel zero-spin rolling conical traction continuously variable transmission

In the existing traction continuously variable transmission (CVT), half toroidal CVT (HT-CVT) is considered to have a better traction performance. However, the HT-CVT has the spin losses due to its structural limitations, which significantly influences the traction efficiency. In this paper, the kinematic qualities and contact models of a novel zero-spin rolling conical CVT (RC-CVT) are studied, and then the rollers and conical disks are compactly designed through the proposed design principles. Subsequently, the transmission efficiency is investigated by using a detailed numerical model and compared with HT-CVT. Based on these computational models and parameters, the practical spin ratio, spin momentum and traction efficiency of RC-CVT are calculated and compared with HT-CVT. The results show that the practical spin ratio and spin momentum of RC-CVT are much smaller than that of HT-CVT, and the efficiency on fixed transmission ratio is consequently higher than that of HT-CVT.