Browse Topic: Transmission gears

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Analysis and optimization of noise and vibrational performance of an e-axle2026-26-03401/16/2026
As the electric mobility landscape evolves, there is a growing emphasis on addressing the Noise, Vibration, and Harshness (NVH) challenges associated with electric drivetrains. The absence of an IC engine in EVs shifts the focus to other noise contributors such as gear meshing, electric machine operation, and structural vibrations. Despite the known influence of micro-geometry on gear dynamics, current optimization practices often rely on empirical adjustments or standard guidelines without fully utilizing advanced computational methods to predict and optimize NVH performance. There exists a pressing need for a systematic approach to analyse and optimize gear micro-geometry to reduce noise and vibration in high-speed e-axle applications. This research aims to bridge that gap by investigating the relationship between micro-geometry optimization and NVH characteristics of an e-axle. Through detailed modelling and optimization techniques, this research aims to identify optimal gear micro
Ankit, Priyadarshi, KULKARNI, KRISHNA, Momin, Vaseem
Multispeed EV Transmission – Gear Shift Simulation and Validation2026-26-01571/16/2026
The advancement of electric vehicle (EV) transmission systems is currently a prominent trend aimed at decreasing carbon emissions and providing eco-friendly transportation alternatives. Most of the EV transmissions are single speed, but research conducted on multi speed EV transmissions show higher efficiency, good performance, high speed and torque demand when compared with single speed counterparts. Most of the multi speed EV transmissions that are developed are of non-synchromesh type, which have direct effect on NVH, driving dynamics and durability of drivetrain components. Due to aforementioned factors, gearshift analysis becomes critical for development. Simulation model is developed at early development phase for initial feedback. Using the feedback, drivetrain can be optimized furthermore and test on physical parts can be conducted for final verification. This paper provides a simulation based approach for modelling non-synchromesh two speed EV transmission using Simulation X
Patel, Hiral, Thambala, Prashanth, Sutar, Suresh, Todtermuschke, Karsten
Drive Cycle Type Identification Using Data Driven Methodologies2026-26-06491/16/2026
Identifying the type of drive cycle is crucial for analyzing customer usage and optimizing vehicle performance and emission control. Methods that rely on geographical location are limited by varying driving conditions at the same location (e.g., heavy traffic during peak hours vs. free-flowing traffic at night). This paper proposes a methodology to identify the type of drive cycle (city, interurban, highway or others) using drive characteristics derived from vehicle data rather than geographical location. Real-world vehicle data from testing trucks is taken, whose drive profiles are already known. Initially, multiple characteristic features of the drive cycle are identified from literature surveys and domain experiences. These features, which can be extracted from basic signal data, include gear shifts, time spent in different driving modes (acceleration, cruise, standstill), velocity distributions, and an 'aggressiveness factor' representing overall driving style. Using ML based
REDDY, MALLANGI PRASHANTH, Gorain, Raju, Ganguly, Gourav
Comprehensive Durability Assessment of Planet Carrier in Heavy-Duty Tipper Gearboxes Using RLDA Torque Data2026-26-04431/16/2026
In heavy-duty tippers, where challenging conditions demand high torque, planet carriers play a crucial role by enabling efficient load distribution and torque transmission while supporting gear ratio and speed variation in space-constrained systems such as automatic transmissions, hybrid drivetrains, and electric vehicles. This paper focuses on the comprehensive durability performance assessment of planet carriers using duty cycles derived from RLDA measurements for a heavy-duty tipper gearbox development program. The existing Design Validation Plan (DVP) for the planet carrier considers first gear utilization of 10-15% at 40% vehicle overload, in line with historical data. However, recent trends in mining applications revealed vehicle overloads of 55-65%, leading to an increase in first gear utilization (25-35%). This shift presents challenges for OEMs to enhance design durability while incorporating additional safety margins to meet the demands of a competitive, cost-driven market
Bagane, Shivraj, Pendse, Ameya
Experimental Evaluation of Metro Rail Bogie Frame through Bench Testing2026-26-05611/16/2026
Bogie frame is a main skeleton and structural member in railway system which is carrying all the loads such as Suspensions,Axles,wheels, car body, Motor, Gear box etc. The frame is subjected the exceptional and service stresses in Vertical, Longitudinal, Lateral and twist directions throughout the service life which should be withstand for a life span of 30 years without failure. The purpose of this project is to determine the Structural integrity of the Metro rail bogie frame in consideration with EN13749 standard .This paper is the outcome of bench testing of metro rail bogie frame with the application of multiaxial loading in static and dynamic campaign through which stress data is collected with strain gauge sensors and correlated with the FEA results at design stage. This helps to verify and evaluate the design and validate the quality of metro rail frame as per the requirement specified in EN13749 European standard in early design stages.
Tormal, Uday Bapurao
Clutch Thermal Adequacy Assessment in Repeat Restart Launch Condition on Gradient2026-26-04341/16/2026
The clutch is a mechanical device that engages and disengages power transmission from the engine to the wheels. It consists of the clutch disc assembly and cover assembly. The clutch disc, with friction material linings, is mounted on the transmission shaft and gets clamped between the flywheel and cover assembly to transmit power as required. However, wear and tear occur due to the differential speeds and slippage between the engine and transmission during operation. Clutch performance is assessed for its thermal behavior under repeat restart conditions on steep gradients, which is essential for the reliability and durability of commercial vehicle clutches. Repeat restart test is a key test to assess clutch performance on a 12% gradient. This test replicates real world scenarios, such as truck launches on hilly terrains under full load, where the clutch experiences significant slippage due to speed differences. This generates heat, and repeated engagements can cause the temperature to
Munisamy, Sathishkumar, Chollangi, Damodar, Mane, Sudhir
A practical approach to reduce Gear Whine noise through gear Tooth contact analysis in an Agricultural Tractor2026-26-03451/16/2026
Customer demand for comfortable tractors has gone multi-fold in last decade. Transmission gear whine noise as one of the major sources of noise, is an important factor influencing the perceived quality of a vehicle and customer comfort. Investigations were carried out on 57HP tractor reported with high whine noise during deceleration from high speeds to low speeds. The source of whine noise is identified through order analysis as spiral bevel gear. Mitigating spiral bevel gear whine noise is always a challenge because of geometry, tooling and assembly requirements. Tooth contact analysis was performed on the spiral bevel gear for simulating the meshing of gear teeth to determine factors like contact patterns, transmission errors, and load distribution. From tooth contact analysis the root cause for high deceleration noise was identified as the motion transmission was not smooth in entry and exit for both forward and reverse. A practical approach of microgeometry optimization was
P, Bharath, p, Priyadarshan, Janarthanan, Devakumara Raja, Chavan, Amit
Performance Evaluation and Optimization of Engine Brake System using Chassis Dynamometer2026-26-05111/16/2026
Engine braking is a deceleration technique that leverages the internal friction and pumping losses within the engine. By closing the throttle and potentially selecting a lower gear, the engine creates a retarding force that slows the vehicle. This practice contributes to better fuel economy, decreased brake system load, and improved vehicle handling in specific driving scenarios, such as steep declines or slippery road surfaces. To alleviate stress on their primary braking systems and prevent overheating, heavy vehicles frequently incorporate engine-based braking. While older trucks relied on simple exhaust brakes with a butterfly valve to restrict exhaust flow, these had limited impact. Hence contemporary heavy vehicles almost exclusively use more advanced engine braking technologies. Traditionally, our heavy-duty vehicles use Exhaust brake system to elevate the braking performance on hilly terrains. Hence an improved sample of Engine brake was developed for enhanced braking
M, Vipin Prakash, Rajappan, Dinesh Kumar, R, Suresh, N, Gopi Kannan
Virtual Validation of ADAS Algorithms Using Driver-in-the-Loop Simulation2026-26-00501/16/2026
Driver-in-the-Loop (DIL) simulators have become crucial tools across automotive, aerospace, and maritime industries in enabling the evaluation of design concepts, testing of critical scenarios and provision of effective training in virtual environments. With the diverse applications of DIL simulators highlighting their significance in vehicle dynamics assessment, Advanced Driver Assistance Systems (ADAS) and autonomous vehicle development, testing of complex control systems is crucial for vehicle safety. A comprehensive review of current research trends reveals key areas of focus such as realism of simulated experiences through improved vehicle dynamics models and advanced sensory feedback. The integration of virtual and augmented reality technologies help to create more immersive and informative simulations to improve the cost-effectiveness and accessibility of DIL simulation platforms. By examining the current landscape of DIL simulator use cases, this paper critically focuses on
Sharma, Chinmaya, Bhagat, Ajinkya, Kale, Jyoti Ganesh, Karle, Ujjwala
Application of DOE Techniques to Identify Factors Influencing Gearbox Synchronizer Wear and Life.2026-26-04891/16/2026
Gearbox synchronizers are essential components for ensuring smooth gear shifting in both manual and automated manual transmissions. The lifespan of a synchronizer is influenced by a complex interplay of several factors, including synchro geometry, lubrication, friction material properties, clutch design parameters, powertrain vibrations, and various operating conditions. These factors contribute to the wear and degradation of synchronizers over time, affecting the overall performance and durability of the transmission system. This paper investigates the influence of various design and operational parameters on the synchronizer's life using a Design of Experiments (DOE) approach. A comprehensive experimental plan was meticulously developed to systematically vary key factors such as synchronizer friction material, the number of cones, lubricant viscosity, and clutch stiffness, among others. The resulting experimental data was analyzed through statistical methods, particularly regression
Jagtap, Amol Shivaji, Koulage, Dasharath, Rudramath, Sagar
Model Based Design of Gear Shift Control for Twin Clutch AMT2026-26-00541/16/2026
Model Based Design (MBD) uses mathematical modelling to create, test and refine systems in simulated environment, primarily applied in control system development. This paper discusses an approach to control gear shifting using shift logic on vehicle level for twin clutch transmission using prototype controller. Twin clutch transmission is a concept with two clutches, one at input end of the transmission called primary clutch and the other at output end of the transmission called secondary clutch. This concept is proposed to counter the challenges with conventional transmission which include increased gear shift time and effort in lower gears, potential rollback of vehicle in uphill condition and chance of missed shifts. The advantages of this concept include reduced gear shift effort and improved synchronizer life with potential for reducing the size of the synchro pack. This paper proposes a methodology to develop shift logic, integrate hardware with software, flashing and calibration
Patel, Hiral, Thambala, Prashanth, Tongaonkar, Yogesh, Mosthaf, Joerg, Malpure, Khushal
Reverse Gear Duty Cycle Generation Using Virtual RLD Simulation2026-26-04051/16/2026
Keywords: RLD (Road Load Data), AVL VSM, AVL Route Studio, Duty Cycle, Transmission, Reverse Gear, Durability The development of transmission systems involves creating duty cycles for bench-level durability evaluations for both forward and reverse gears. For forward gear, vehicles are driven under various real-world conditions over thousands of kilometers, equipped with numerous sensors and components tailored for data collection. In contrast, duty cycles for reverse gear are often based on prior experience or rough estimations due to the lack of clear definition of real world use case. Reverse gear RLD is particularly scarce, especially for heavy-duty vehicles operating in off-road or mining environments, where specific reverse driving paths are not typically followed. This paper presents a detailed methodology highlighting the importance of reverse gear duty cycles by leveraging virtual RLD simulations on various gradients using tools such as AVL Route Studio and AVL VSM. By
Kansagara, Smit, Patel, Hiral, kira, Lucas, Sutar, Suresh, Soor, Debasis
The selection of a two-speed gearbox for small commercial electric vehicles aims to optimize powertrain efficiency2026-26-04171/16/2026
In response to the significant environmental challenges posed by climate change driven by global warming, the automotive industry is accelerating the transition toward electrification. While electric vehicles offer considerable potential for mitigating CO₂ emissions, their elevated upfront costs pose a notable challenge to large-scale market penetration. Energy efficiency improvement of electric vehicles is emerging field of research to reduce total cost of ownership. Electric vehicle powertrain component selection in small commercial vehicles including three and four wheelers is a complex process which has to fulfil multiple requirements Range, performance, drivability, packaging, total cost of ownership of vehicle and comfort. In addition, powertrain configuration including battery, motor and transmission ratio selection plays a fundamental role in cost of electric vehicle. Hence, The task of selecting the right powertrain configuration, encompassing architecture, motor selection
Wani, Kalpesh, Jadhav, Vaibhav, Shendge, Raman, Warule, Prasad
Optimization of Propeller shaft design to eliminate Launch Undulation (Lateral shake) and Vibration level2026-26-03341/16/2026
During vehicle launches in 1st gear, a lateral shake (undulation) and a pronounced metallic hitting noise were observed in the underbody. The noise was identified as the propeller shaft's second universal joint (UJ) yoke striking the fuel tank mounting bracket. Sensitivity to these issues varied with acceleration inputs: light pedal input during a normal 1st gear launch on a flat road resulted in minimal undulation, whereas wide open throttle (WOT) conditions in 1st gear produced significant lateral shake and intensified hitting noise. Further investigation revealed that the problem persists across all gears and occurs consistently during normal driving conditions, with continuous impact between the propeller shaft yoke and the fuel tank mounting bracket. Extensive experimental measurements at the vehicle level indicated that these issues were primarily caused by the center-mounted propeller shaft joint deviating from its central position and rotating eccentrically under torque. This
Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran
Development and Validation of a 1D Model for Evaluating Transmission Efficiency in Vehicles2026-26-00661/16/2026
This study develops a one-dimensional (1D) model to enhance transmission efficiency by evaluating power losses within a transmission system. The model simulates power flow and identifies losses at various stages such as gear mesh, bearing, churning, and windage losses. Using ISO/TR 14179, which provides a method for calculating the thermal transmittable power of gear drives with an analytical heat balance model, the 1D model ensures accurate thermal capacity evaluation under standard conditions. A key advantage of this 1D model is its efficiency in saving time compared to more complex 3D modelling, making it particularly useful during the conceptual stage of transmission system development. This allows engineers to quickly assess and optimize transmission efficiency before committing to more detailed and time-consuming 3D simulations. To validate the model, experimental tests were conducted at various motor speeds (RPM) and torque values, using high-precision sensors and dynamometers
Bandi, Nagendra Reddy
FATIGUE FAILURE ANALYSIS FOR AUTOMOTIVE TRASNMISSION2026-26-05771/16/2026
A fatigue failure in the transmission input shaft was identified during a bench-level endurance test under 2nd gear loading conditions. The test transmission’s input shaft comprises fixed 1st, reverse, and 2nd gears, with the remaining gears mounted as floating. The shaft was subjected to cyclic torsional loads, and failure occurred after a defined number of cycles. Metallurgical analysis revealed a brittle fracture surface with crack initiation at the outer surface, propagating to core in a helical pattern, ultimately resulting in complete shaft fracture. To monitor and replicate the failure, the test setup was instrumented with a Reilhofer Delta Analyzer for early fault detection. TTL signals from accelerometers mounted on the transmission and a bench speed sensor were fed into the system, which generated FFT spectra and trend indices. A warning alarm triggered upon deviation in the trend index, indicating premature damage initiation. The test was subsequently halted for component
Navale, Pradeep, Kushwaha, Rakesh, Patel, Hiral
Gear Shift Validation of Multi Speed EV transmission on Test Bench using Vehicle Control Unit2026-26-05321/16/2026
Electric vehicle (EV) transmissions play a vital role in powering EVs by channelling energy from the electric motor to the wheels. Recently, the focus has shifted to multi-speed transmissions in the EV sector due to their potential to improve efficiency and performance. By utilizing various gear ratios, these transmissions enable the motor to function within its most efficient range across different speeds. Most of these transmissions need electronic control unit (ECU) with software for optimal functionality and smoother gear shifting. These controllers incorporate controller area network (CAN) communication protocol to operate along with other ECUs. Thus validation of these transmissions is a challenge as they are clutch less, motor has to be controlled for speed matching and have electro mechanical systems replacing conventional systems for operation. This paper proposes a methodology to validate multispeed EV transmissions on a test bench. The validation setup consists of electric
Thambala, Prashanth, Patel, Hiral, Soor, Debasis
Multibody Dynamic Analysis of Belt-Type CVT Systems in Two-Wheelers: A Study on Slip, Misalignment, and Transmission Efficiency2026-26-00791/16/2026
More efficient drivetrain technologies are in greater demand in the two-wheeler market as a result of the introduction of BS6.2 emission standards. In order to satisfy these performance and regulatory requirements, Continuously Variable Transmission (CVT) systems—which are renowned for their stepless gear shifting and increased fuel efficiency—are being given more and more consideration. However, because CVT is nonlinear and multibody dynamic, accurately predicting its behavior is still a difficult task. With an emphasis on variables like belt slip, pulley misalignment, and transmission efficiency, this study provides a thorough multibody dynamic analysis of a belt-type CVT system used in two-wheelers. High-fidelity analysis of the belt-pulley interaction under various load and speed conditions is now possible thanks to the development of a novel modeling methodology using advanced multibody dynamics simulation software – Virtual Dynamics. The method makes early design validation
Mane, Prashant, Shah, Swapnil, Voncken PhD, Antonius, Pinjari, Abrar, Emran, Ashraf, Mane PhD, Shrikala
Minimum Weight Design of an Electronic Continuously Variable Transmission for Rotorcraft ApplicationsF-0081-2025-02905/20/2025
This paper, explores the design and sizing of a planetary gear-based electronic continuously variable transmission (ECVT) for implementation of a parallel gas-electric hybrid helicopter propulsion system. The ECVT consists of a differential planetary gear transmission (PGT) and an electric motor/generator (MG) unit. The ECVT enables power-flow between engine, motor and helicopter main rotor. The parallel arrangement enables the main rotor speed to varied continuously based on the MG speed while the engine speed can remain constant. The performance benefits enabled by the main rotor speed variation capability are offset by the added weight penalties introduced by the ECVT system. By considering factors such a as gear tooth bending and contact stress, bearing loads, required motor torque, planetary gear kinematics and pitch-line velocity constraints, this paper conducts a minimum mass design study for several PGT / ECVT arrangements. Here, three different single stage PGT/ECVT
DeSmidt, Hans, Ai, Zhisheng
Dynamics of a Variable Speed Hybrid-Electric Helicopter Propulsion SystemF-0080-2024-12525/7/2024
In this paper, a comprehensive dynamic simulation of a parallel hybrid gas-electric single main rotor helicopter involving a motor/generator (MG) pair and a differential planetary gear transmission (PGT) arrangement forming an electronic continuously variable transmission (E-CVT) was performed. This notional hybrid electric helicopter was sized based on a retrofit of a dual engine, 10000 lb, 2500 Hp class helicopter. The total weight added by the electric components was 182 lbs which increased the propulsion system weight from 1184 to 1366 lbs. The simulation results found that at 110 kts cruise, the hybrid electric system enabled a 27% reduction in main rotor rpm which resulted in an 18% reduction in the fuel burn rate. It is concluded that use of an E-CVT parallel hybrid propulsion system offers potential for increased flight range and reduced fuel consumption in medium to large-scale helicopter applications.
DeSmidt, Hans, Ai, Zhisheng
The Influence of Torsional Vibrations on the Longevity of Manual Transmission Synchronizers and the Durability of Clutch Dampers2024-01-50101/25/2024
This study delves into the impact of engine torsional vibration on transmission component failures, specifically synchronizers and clutch damper springs. Synchronizers are crucial in ensuring smooth gear shifts by synchronizing the rotational speeds of the transmission input and output shafts. While design factors such as geometry, friction material, and lubrication are often attributed to synchronizer failures, engine-generated torsional vibrations significantly affect their lifespan. Clutch damper mechanisms integrated into the clutch disc are designed to mitigate these vibrations. This research employs 1D powertrain simulation modeling to predict powertrain torsional vibration behavior. Additionally, rig tests are conducted to simulate vehicle-level angular accelerations and examine the impact of torsional vibrations on synchronizer life. The results provide valuable insights into optimizing clutch damper design to effectively dampen vibrations and prolong transmission component
Jagtap, Amol, Rudramath, Sagar, Chollangi, Damodar, Bhandari, Kiran
CAE Based Benchmarking of Shaft Deflection for Transmission Gear Rattle Noise2024-26-02451/16/2024
Vehicle transmission gear rattle is one of the most critical NVH irritants for refined vehicles. It is perceived more dominantly in lower gears of vehicle running. It depends on various design parameters like Input torque amplitude & fluctuations, driveline torsional vibrations, gear micro & macro geometry, shaft flexibility, etc. Establishing exact contribution of each of these parameters to transmission rattle, thru experimental or simulation technique, is very challenging. Current paper explains the NVH CAE benchmark approach deployed to understand difference in rattle behavior of two transmission designs. Subjective and objective evaluation shows that one is better than the other for rattle noise. Paper focuses on simulation and comparison transmission shaft deflection as a measure of transmission rattle. FEA based nonlinear static simulations are carried out by applying torque induced forces at each of the gear contacts for all the gear engaged conditions. Simulated shaft
Bijwe, Vilas B., Kulkarni, Shriram, Vaidya, Rohit, Shah, Bhartendra
Gearshift Simulator – Perceive Gearshift Feel at Early Development Stage2024-26-02921/16/2024
One of the very first customer touchpoint in a vehicle is quality of gear shifting. Gearshift quality is perceived as a symbol of refinement, robustness of a vehicle. Globally, lot of efforts are taken to refine the gearshift quality. Design improvements in internal components of transmission, cable and shifter assembly, knob design iterations are carried out to arrive at optimum gearshift quality at the vehicle level. Current practice for this activity includes processes such as design modification, manufacturing of proto components, assembly of components and fitment in the vehicle. This vehicle is then instrumented with sensors and data acquisition units to capture the parameters which determine the gearshift quality. This is an iterative process which goes on until necessary refinement/improvement is achieved. This process requires investment of lot of time, efforts and the budget. This paper describes a virtual approach to arrive at optimum design of components. This paper gives
Tongaonkar, Yogesh Manohar, Patel, Hiral, Thambala, Prashanth, halingale, Amol
Integrated testing at lab from road by doing conversion and correlation between Subjective to objective assessment on ride comfort parameter of gear shifting quality in Two- wheeler.2024-26-03271/16/2024
The evaluations of ride comfort in gear shifting have been known as one of the dominant factors for vehicle quality assessment. However, those factors have not been assessed and analyzed objectively in-depth in conjunction and integration with general ride and handling parameters. In recent, the criteria set by customer have changed on account of heightened expectations, resulting in a growing demand for enhanced ride comfort. the quality of gear shifting experienced by a customer is evaluated subjectively on road leads to difficulty in arriving inferences and taking decisions due to variation in responses of people on the same situation. This study is involved the process of conversion from subjective to objective assessment on gear shifting quality by identifying the objective parameters for contributing the quality of gear shifting feel. Measuring and analyzing those parameters like lever travel, lever effort, and noise while shifting during dynamic condition at vehicle level on
Manoranjan, R., K S, Sreekanth
Experimental Evaluation of Metro Rail Bogie Frame through Bench Testing2024-26-03251/16/2024
Bogie frame is a main skeleton and structural member in railway system which is carrying all the loads such as Suspensions, Axles, wheels, car body, Motor, Gear box etc. The frame is subjected the exceptional and service stresses in Vertical, Longitudinal, Lateral and twist directions throughout the service life which should be withstand for a life span of 30 years without failure. The objective of this work is to estimate the structural integrity of the Metro rail bogie frame .This paper is the outcome of bench testing of metro rail bogie frame with the application of multiaxial loading in static and dynamic campaign through which stress data is collected with strain gauge sensors and correlated with the FEA results at design stage. This helps to verify and evaluate the design and validate the quality of metro rail frame as per the requirement specified in EN13749 European standard in early design stages.
Tormal, Uday Bapurao
Noise reduction on electric two wheeler by structural modification and gear design optimization2024-26-02151/16/2024
The low running cost of electric two wheelers is resulting in high popularity and growing market share. The electric two wheelers are generally considered silent. However, the tonal nature of radiated noise is annoying for both driver and pedestrians in electric vehicles. This study focuses on electric two wheeler with annoyance issue. The customer complained about non-linear noise with respect to speed and also whining during loading and coasting. The detailed Noise Source Identification (NSI) revealed that the noise is due to motor whine and structural resonances of chassis excited by this motor excitation during runup and gear whine orders during coasting when excitation by motor is absent. The motor mounting and chassis are structurally modified with suitable vibration isolators based on the results of modal analysis. The transmission gear geometry and contact pattern are optimized for transmission error reduction. The modification resulted in 6-8 dB overall noise reduction with
Chivate, Shriniwas Dilip, Gaikwad, Atul Annasaheb, Taware, Ganesh Nanasaheb
Investigation of Synchronizer Ring Failure in a Commercial Vehicle Transmission2024-26-03831/16/2024
The commercial vehicles market is dominated with manual transmission, due to less ownership cost. Generally, the commercial vehicles are used in large numbers by the fleet owners. The transmission endurance life is very important to a vehicle owner. On the other hand, the driver fatigue can be reduced with smooth change process. The gear change process in a manual transmission is carried out with the help of the synchronizer pack. The crucial function of synchronizer pack in an automotive transmission is to match the speed of the target gear for smooth gear shifting. In a transmission the loose and the weakest part is the synchronizer ring. The failure of synchronizer affects smooth gear shifting and it also affects the endurance life of the transmission. The synchronizer ring can fail due to poor structural strength, synchronizer liner wear, synchronizer liner burning etc. The synchronizer liner burning is very difficult to analyze since the liner wear pattern are very uneven and the
Jamadade, Gajanan, K, Barathi Raja, Chatterjee, Soumik
Reduction of Gearbox noise by optimizing Gear micro geometry2024-26-02341/16/2024
Vehicle noise level has to be maintained within the limit specified by Pass By Noise (PBN) standards to meet the regulatory requirements. Gearboxes and engines are the main sources of noise in a vehicle, owing to the mechanical and physical processes involved. The noise problem in transmission system is characterized by high amplitude acoustic signals, and the gear mesh noise can be indirectly estimated using the Transmission error parameter. Transmission error is defined as the difference between the actual position of the output gear and the position it would occupy if the gear drive were perfect, which can be attributed to various factors such as tooth profile errors, misalignment, and tooth deflections. A six-speed manual transmission commercial vehicle is observed to exhibit higher noise levels during the vehicle PBN test. The gearbox is modelled in Romax gearbox simulation software and the transmission error value is identified to be high. The micro geometry parameters lead
G R, Santosh Kumar, Ks, Dhianeshwar, Basim, K Mohammed
Lubrication Effectiveness Determination for Wet-Sump Transmissions using Multiphase Computational Fluid Dynamics Modeling2024-26-02981/16/2024
Wet-sump transmissions are widely used in heavy duty and medium duty vehicles. As these transmissions do not have a dedicated forced lubrication system, it is important that the gear train, shafts, and enclosure are designed appropriately so that enough oil splashes to critical locations to ensure sufficient lubrication. The lubrication effectiveness of such transmissions can be studied through detailed tests or numerical simulations. Often, the vehicle, and therefore the transmission, encounters some severe operating conditions, such as climbing on an incline, driving downhill, etc. Studying these conditions through tests is an expensive process and this imposes the need for an analysis first approach. In this paper, 3D multiphase Volume of Fluid (VOF) method is used to examine two such extreme cases: an 8-degree tilted installation of transmission in a vehicle, and an inclined condition of transmission during 10-degree uphill climb. By studying the oil volume fraction on gears and
r, Shamini, Sachdeva, Aniket, Handa, Joji, Sena, Carlos, Marson, Luigi
Analysis of Dynamic Characteristics and Load Sharing Performance of Electric Driven Planetary Gear System Based on Electromechanical Coupling Model2023-01-701110/30/2023
Due to the multi-gear configuration and high integration of electric drive systems in electric vehicles, it is necessary to investigate the influence of drive motor torque fluctuation on the dynamic characteristics and load sharing performance of planetary gear transmission systems. Considering both motor torque fluctuation and internal excitations of the transmission system, a dynamic model of the electromechanical coupled system is established by combining the Maxwell motor electromagnetic model with the planetary gear dynamics model. Based on the proposed model, the dynamic characteristics, dynamic load performance and load sharing performance of the system considering motor torque fluctuation are analyzed, and the improvement of system load sharing performance due to sun gear floating is discussed. The results show that motor torque fluctuation leads to more complex dynamic response and causes the vibration displacement amplitude to more than doubled. Furthermore, the system
Guo, Fang, Li, Chen, Su, Jinzhan, Liu, Chao
Global Vehicle Vibration Enhancement Using Circular Force Technology2025-01-00155/5/2023
In addition to safety advantages, sound and vibration are being utilized to enhance the driver experience in Electric Vehicles (EVs). Significant interest and investment continue to grow in utilizing interior and exterior sound for pedestrian safety and driver awareness of vehicle state, as well as enabling a unique personal EV audio experience for brand recognition both inside and external to the vehicle. Several automakers are also using audio to simulate virtual gear shifting and as well as manual transmissions in EVs. According to several automotive industry articles and market research, the audio enhancements alone, without the vibration that drivers are accustomed to in combustion engine vehicles, are not sufficient to meet the engagement, excitement, and emotion that driving enthusiasts expect. In this paper, we introduce the use of new automotive high-force compact light-weight circular force generators for globally shaking vehicles. The technology was developed originally for
Norris, Mark A., Orzechowski, JEFFREY, Sanderson, Brad, Swanson, Douglas, vantimmeren, Andrew
Research on the control strategy of active gear shifting sound quality in the vehicle2025-01-00195/5/2023
The active sound synthesis system of electric vehicles plays an important role in improving the sound perception and transmission of working condition information inside the vehicle. Nowadays, the active sound synthesis system inside the vehicle has become standard in electric vehicles of major Major automobile manufacturing plants to meet the user groups' demand for driving and riding experience. Starting from the existing in-vehicle active sound synthesis algorithm, this paper designs a gear shift control strategy suitable for all working conditions. During acceleration, in order to achieve the gear shifting effect, the motor speed signal is obtained to bias the speed at the shift point. During deceleration, in order to prevent a sudden increase at the shift point, the speed of the deceleration condition is linearly interpolated to make the shifting process of the deceleration condition smoother. During acceleration after deceleration, in order to avoid the uneven sound jump at the
xilong, zhou, Liu, Zhien, Xie, Liping, Lu, Chihua, Yu, Shangbo, GAO, XIANG, yongsheng, wang
A Time Efficient Thermal and Hydrodynamic Model for Multi Disc Wet Clutches 2022-01-07863/29/2022
Wet Clutches are used in automotive powertrains to enable compact designs and efficient gear shifting. During the slip phase of engagement, significant flash temperatures arise at the friction disc to separator interface as a result of dissipative frictional losses. An important aspect of the design process is to ensure the interface temperature does not exceed the material temperature threshold at which accelerated wear behaviour and/or thermal degradation occurs. During early stages of a design process, it is advantageous to evaluate numerous system and component design iterations exposed to plethora of possible drive cycles. A simulation tool is needed which can determine what are the critical operating conditions that need to be validated for the system performance and durability to be assured. This paper describes a time-efficient multiphysics model developed to predict clutch disc temperatures with a runtime of minutes. It consists of a simplified 1D numerical model of heat
Morris, Samuel Adam, Morris, Nicholas John, Leighton PhD, Michael
Development of vehicle virtual test rig for powertrain dynamics characterization 2022-01-07833/29/2022
Simulating driveline NVH is a prominent and critical factor during new vehicle development. Driveline performance depends on accuracy of loads consideration and boundary condition of the vehicle systems. The evaluation of transient and steady state behavior of driveline system depends on participation from vehicle subsystems such as suspension, tire, body in combination with the driveline components like powertrain, flywheel, clutch, propeller shaft, differential and driveshaft. This work describes the development of a test rig in the virtual dynamic’s environment, consisting of virtual transmission and driveline assembled with full vehicle model. Roller rigs are developed and incorporated at the front and rear wheel ground integration points for excitation mechanism, it also accounts for tire slip factors and contact forces. A RWD ( rear wheel drive) vehicle model is considered for capturing major driveline transient and vibration event such as tip in/ tip out, gear shifting and
BHATTACHARYYA, INDRANIL
Experimental evaluation and VECTO simulations of a hybrid electric bus2022-01-08073/29/2022
New heavy-duty vehicles are simulated with the Vehicle Energy Consumption Calculation Tool (VECTO) to certify their fuel consumption and CO2 emissions in the European Union. VECTO is planned to be utilized also for the certification of vehicles with hybrid electric powertrains, in all topological configurations spanning from P0 to P4 parallel systems as well as series hybrids. A development version of VECTO able to simulate these configurations is already available and was used for this study. In this work we have collected available measurement data from a specific P2 hybrid bus which was run in WHVC on the dyno as well as on the road and a vehicle model was created in VECTO. The VECTO Hybrid Controller was evaluated by comparing the measured and simulated decisions on utilizing the available power sources (fuel/stored electric energy), on regenerating braking and on gear shifting, on a step by step base as well as on a cycle average CO2 emissions result. The results show a good fit
Bitsanis, Evangelos, Broekaert, Stijn, Tansini, Alessandro, Fontaras, Georgios
Innovative Experimental Approach towards Gear Rattle Investigation2022-01-07843/29/2022
Today’s customers are very thoughtful towards a new vehicle purchase. Along with the vehicle performance, overall vehicle NVH quality is also one of the most important factor which affects their buying decision. During any new product development, gearbox rattle noise is a fundamental NVH problem which requires to be addressed and solved in the early stages. Gear rattle is an annoying noise phenomenon of the automotive transmission, which is mainly induced by torsional fluctuation of engine. This fluctuation is passed from clutch system to the transmission. The torsional vibration causes the free gears inside the transmission to impact each other, which generates so-called the gear rattle noise. The noise source of the gear rattle in the manual transmission is due to the impact of gears oscillating through their gear backlash and the noise will transfer into the vehicle cabin through the transmission case via shafts, bearings and vehicle structures. This paper describes an experimental
Vaishya, Abhishek Lakhanlal
Comparison of sensing modes for stray-field-immune magnetic angle sensors2022-01-07573/29/2022
Magnetic angle sensors play a major role in engine control, steering, and numerous other automotive applications like pedal, wipers and gear shift position sensing. With vehicle electrification, these sensors are increasingly exposed to parasitic magnetic stray fields. When shielding is not an option, a differential scheme is an alternative, where the sensor responds to magnetic field gradients. Two such schemes were previously introduced to reject stray fields to some degree. For these two modes, there are engineering trade-offs between the key performance parameters (noise, thermal drift, angular range). Often, these trade-offs are misunderstood by sensor users. This paper investigates these trade-offs by comparing the two stray-field-immune magnetic sensing modes. We use a single programmable integrated sensor supporting both modes for a direct comparison. The integrated sensor is designed for safety critical automotive applications. Two independent dies are integrated in the same
Lefebvre, Christopher, Mazzilli, Francesco, Laville, Arnaud, Bidaux, Yves, Close, Gael
Vibration analysis of Gear defects using Machine learning approach2021-28-018210/1/2021
Gear drives are considered as the most effective transmission method in automobiles as well as in various industries because of its high efficiency, reliability and high velocity ratio. As a result, from its trustful usage, failure in any part may lead to a large and unpredictable production loss along with massive service cost and safety concerns. Periodic maintenance and condition monitoring are the only solution to avoid the above scenario. Vibration analysis are most sounded term in the fault detection due to its runtime condition monitoring and low cost. Nowadays, vibration analysis was off set to machine learning methods, which is a modern technique enable us the automation such that the system can learn from the input data and make decision with a nominal human interface were as conventional methods are highly operator dependent. Here in this study, the effectiveness of a machine learning based gear fault diagnosis system is studied. Gear defects like surface pitting
prasad SR, Vishnu, Poulose, Jasmine, Sadique, Anwar
Shift fork design using finite element simulations2021-28-024410/1/2021
Shift fork and shift fork are key shifting element in manual and dual clutch transmission for smooth operations of gear shifting. One of the main criteria for robust design of shift fork and shift swing is stiffness symmetry. Stiffness symmetry ensures straight movement of sleeve onto hub and thus helps in achieving good shift quality. Stiffness symmetry also ensures equal load distribution across two or three pads of shift fork while operation. In this paper we intend to demonstrate finite element simulation driven design process to improve stiffness symmetry of shift fork and shift swing. Various parameter affecting stiffness symmetry are analyzed through design of experiment and selected best range for optimum design of shift fork and shift swing. Output of this study will be useful for improving any design of shift fork to meet different targets of stiffness symmetry for all automobile suppliers and manufactures.
PRAYAGA, GIRIDHAR KRISHNA, sahu, Deepak Kumar
Optimization of Clutch pedal Vibration with hydraulic damper & influence on its position in resolving the vibration without compromising Efficiency of the system2021-28-024710/1/2021
The clutch pedal in manual transmission plays a significant role in defining the comfort of driver as the component is one of the customer's touchpoint in the vehicle. Whenever driver operates the clutch pedal, comfort & NVH refinement should be felt over the complete pedal travel. The expectations of customer on NVH refinements, such as pedal vibration felt on foot during actuation, becomes the part of perceived Quality and hence addressing the concern is very crucial. Due to advancements of technology & down-sizing of engines, NVH becomes the challenging area where the clutch pedal vibrations need to be eliminated to improve the comfort. In this paper we are explaining the problem statement & NVH solution to eliminate the clutch pedal vibration observed during clutch pedal actuation. Pedal vibrations were very severe at 10% clutch pedal pressed condition, and the same tends to diminish till 50% clutch pedal pressed condition. From initial position (0% clutch pedal pressed condition
S, Kesavprasad, Vellandi, Vikraman, M, Sudhan, Vijayarangan, Deepak
Methodology To Derive RLD Based Durability Test Schedule For Gearbox Oil Seals2021-26-04619/22/2021
Oil seal leakage is one of the major failure mode in gearbox / transaxle. Oil seal failures can be due to various reasons like high temperature, insufficient lubrication, failure due to external environment, incorrect fitment etc. Major reason for oil seal failure is insufficient oil flow inside gearbox when vehicle is running on gradient for long duration. When vehicle is running in hilly region, transmission will get incline leading to oil deficiency at one half of the transmission. Oil seal in this location will not get sufficient lubrication and will run dry. Also, there will be rise in local temperature at seal lip to shaft interface leading to failure of oil seal lip. Subsequently, oil leakage from transmission will start from this location when vehicle is running in different terrain. Due to continuous seepage, oil quantity in the transmission will get reduced and may lead to gear failure or seizure of bearing. Some OEM use transmission with transparent housing for lubrication
Uttamani, Rahul, Tendulkar, Vishveshvar, Navale, Pradeep, Kumar, Ravi, bhavikatti, Gururaj
Development of Closed Loop Power Recirculating Type Test Rig - Higher Torque Ranges2021-26-04919/22/2021
In the past decades, many impressive progress has been made in the rig development for the gear validation. But, the challenges are to test the entire gear box for the improvement in the single gear alone to ascertain material quality or process improvement, that too with the higher torque range gear boxes, which requires huge investment and power consumption due to high capacity test rig / dynamometer. This paper deals with an experimental validation of the dynamic model for a gear pair test system, representative of a closed loop power recirculating type test rig. Being a closed loop, this system has its own uniqueness, that, it uses the low capacity prime mover, which considers the initial starting loop torque only, to cater the high power requirement in an efficient manner. The key intend of the development of this rig is to reduce the testing from system level to sub component level with low cost operation and more competence for the gears of high torque application. This also
Rajaraman, Manikandan, Srinivasan, Sriraman, Muthu kumar, Pandurangan, N, Gopi Kannan
Customized and market specific thermal robust clutch system solution2021-01-12399/21/2021
The goal of reducing fuel consumption and CO2-Emission is leading to turbo-charged combustion engines that deliver high torque at low speeds (down speeding). To meet NVH requirements damper technologies such as DMF (Dual Mass Flywheel) are established, leading to reduced space for the clutch system. Specific measures need to be considered if switching over from SMF (Single Mass Flywheel) to DMF. It has an impact on thermal behavior of the clutch system for example due to reduced and different distribution of thermal masses and heat transfer to surroundings. Taking these trends into account, clutch systems within vehicle power-trains are facing challenges to meet requirements e.g. clutch life, cost targets and space limitation. Clutch development process must ensure to deliver a clutch system that meets requirements taking boundary conditions such as load cycles and driver behavior into account. Relevant load cycles are derived based on feedback & an analysis of driver behavior under
Kapse, Ravi Ramesh, Lakshminarayanan, Saravanan, Németh, Ákos, Thakare, Ankit, Bernhardt, Johannes
Ford engineered 2022 Bronco to give Jeep the willies21AUTP08_098/1/2021
Ford engineers refused to utter a single bad word about Jeep Wrangler during the course of the week-long 2022 Bronco media drive event in Austin, Texas. In fact, some among that gracious bunch admitted, ahem, that they may have owned and modified a Wrangler or two in their lifetimes. Jeep's profit-spinning 4x4 icon has that effect on competitors and fans alike. And it “has had this space to itself for decades,” noted Eric Loeffler, chief program engineer for U725, Ford's code for the new Bronco. About five years ago, Ford decided to unseat the Jeep's monopoly. The result is a modern take on another historic nameplate that finally brings Wrangler a truly serious competitor - and beats it in at least three key areas.
Brooke, Lindsay
The Effect of Hub Moment on Main Rotor Shaft Drive GearsF-0077-2021-168865/10/2021
ABSTRACT
Binney, David, Hunte, Brian, Liu, Lin, Wright, Zach
Minimum Weight Design of a Two Speed Dual Clutch Offset Compound Gear Transmission for Rotorcraft ApplicationsF-0077-2021-168885/10/2021
ABSTRACT
DeSmidt, Hans, Ai,  Zhisheng
Analysis of Vehicle GPS and Derived Speed Data from BMW NBT Evo Systems Acquired with Berla iVe2021-01-09064/6/2021
Many late-model BMW vehicles are equipped with an NBT Evo infotainment system. This system is seen in BMW vehicles in all global markets. Like infotainment systems from other manufacturers, this system records data elements that can prove to be key evidence to investigators of vehicular incidents. This system records timestamped tracklogs that consist of GPS coordinates paired with date/time data. These tracklog points, however, are not recorded in regular intervals. Testing of an instrumented BMW 430i was conducted in and around the Bruntingthorpe Proving Grounds in the United Kingdom. The test vehicle was instrumented with a Racelogic Video VBOX Pro. Data from the instrumentation was compared to the data acquired from the BMW by the iVe Ecosystem from Berla Corporation. The accuracy of the GPS coordinates recorded in the BMW tracklogs was determined by computing the distance between the recorded BMW data and the reference instrumentation data. The derived speeds computed in iVe from
Vandiver, Wesley, Anderson, Robert
Comparison between Different Modelling Methods of Secondary Path to Maximize Control Effect for Active Engine Mounts2021-01-06684/6/2021
Active engine mount (AEM) is an effective approach which can optimize the noise, vibration and harshness (NVH) performance of vehicles. The filtered-x-least-mean-squares (FxLMS) algorithm is widely applicated for vibration attenuation in AEMs. However, the performance of FxLMS algorithm can be deteriorated without an accurate secondary path estimation. First, this paper models the secondary path using finite impulse response (FIR) model, infinite impulse response (IIR) model and back propagation (BP) neural network model and the model errors of which are compared to determine the most accurate and robust modeling method. After that, the influence of operation frequency on accuracy of the secondary path model is analyzed through simulation approach. Then, the impact of reference signal mismatch on the control effect is demonstrated to study the robustness of FxLMS algorithm. Finally, a test bench is established to optimize other control parameters and validate the performance of the
Zhou, Ziwei, Guo, Rong, Xu, Shuheng
Lead Mismatch Calculation of a Helical Gear System Mounted on Balance Shafts2021-01-06734/6/2021
In powertrain systems, combined deflection of loaded gear tooth as well as that of the shafts on which the gears are mounted is responsible for non-ideal meshing conditions. Uneven load distribution along the teeth between mating gears is one such non-ideal condition that can cause significant NVH issues. Lead mismatch, defined as the amount of mismatch along a pair of gear tooth faces, is a critical parameter to maintain uniform load distribution at the gear contact regions. If each of the adjacent shafts is a balance shaft where a counterweight is mounted at an eccentric location, shaft deflection and the resultant lead mismatch is even more. Also, typically, balance shafts are required to rotate at twice the crankshaft speed. At a high engine speed, Coriolis and centrifugal accelerations acting on the balance shafts can be significant resulting in higher shaft deflection and greater lead mismatch. In the present system, a balance shaft mechanism with helical mating gears are
Chowdhury, Sanjib, Vasu, Anoop, Chung, Jerry, Mehta, Yogesh
Predictive Gearbox Oil Temperature Using Machine Learning2021-01-01824/6/2021
Gearbox is one of the most defining components for vehicles, turbines and other applications. A failure in the gearbox would ultimately cause the system to breakdown and thus results in operational failure. A gearbox failure can be attributed to several factors such as gearbox oil temperature, driving patterns, dependent engine components and other various gearbox performance. The focus of this paper is gearbox oil temperature sensor which is the one important factor that determines gearbox overheating and influence the system to take precautionary steps in switching from different types of oil to prevent risk of damaging their equipment and expensive repair. The goal of this paper is to predict the gearbox oil temperature sensor failure by adopting machine learning techniques. Various Machine learning (ML) techniques such as Support vector machine, Decision trees and Random forest etc are employed in this paper to achieve the objective. We also evaluate the performance of different ML
Gandi, Varaprasad
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