Browse Topic: Gears

Items (1,954)
Gears are essential components in industrial machinery, and their design needs to be optimized to ensure the proper functioning of mechanical systems across various industrial applications. In this study, an optimization approach is proposed to determine the optimal design of a spur gear. This approach is based on an improved Jaya algorithm, which features a straightforward formulation without any algorithm-specific control parameters. Utilizing a simple and parameter-free updating mechanism, the strength of this algorithm lies in its iterative ability to enhance candidate solutions by moving them toward the best solution while avoiding the worst one, providing a flexible framework for optimization. However, since the original Jaya algorithm was primarily designed for continuous optimization problems, this research incorporates adjustments to adapt it effectively for mixed-variable optimization problems and to manage multi-objective functions. The effectiveness of the proposed
Rezki, InesFerhat, DjeddouHamouda, AbdelatifAbderazek, Hammoudi
For the team at SmartCap, building top-notch gear for outdoor adventurers isn’t just a business — it’s a passion driven by their own love for the wild. But as demand for their rugged, modular truck caps soared after their move to North America in 2022, they hit a snag: How do you ramp up production without sacrificing the meticulous quality you are known for, all while navigating a tough labor market? Their answer? A bold step into the world of intelligent automation, teaming up with GrayMatter Robotics, and employing the company’s innovative Scan&Sand™ system.
In electrified drivetrains, lubricants are commonly in contact with the motor and other electrical components as well as the gears and bearings. Copper, present in these electrical components, is susceptible to corrosion by fluids containing active sulfur, which can lead to catastrophic failure of the unit. Lubricating fluids for electric vehicles (referred to as e-fluids) must not cause corrosion and must maintain high performance while having suitable electrical conductivity, material compatibility, and heat transfer properties. We describe a new formulation without active sulfur that has recently entered the market, which can protect against copper corrosion. We show that this e-fluid can provide suitable wear protection under field trial conditions, and that the e-fluid provides improved wear protection in bearing (FE-8) tests compared to a traditional extreme pressure axle fluid (API GL-4). Surface analysis (X-ray photoelectron spectroscopy) measurements of the component surfaces
Hopper, Elizabeth R.Williams, Megan S.Gahagan, Michael
Reducing gear rattle noise within the passenger cabin is a crucial objective in vehicle development due to its direct impact on customer comfort and driving experience. Gear rattle occurs when free gears collide during meshing, primarily driven by high torsional vibrations generated by engine fluctuations. These vibrations are transmitted through the clutch system to the transmission, amplifying noise inside the cabin. This study focuses on optimizing the clutch by stabilizing its hysteresis to address this issue. This helps minimize the torsional vibrations transferred to the transmission input shaft, thereby reducing gear rattle. The investigation centers on a case where significant gear rattle was observed at high vehicle speeds, particularly under high engine torque conditions. A thorough root cause analysis identified that the primary contributor to the noise was a drop in the clutch hysteresis value at elevated engine torques. This drop increased torsional vibrations in the
Awasthi, MradulDhankhar, Dinesh SinghKhare, Devendra KumarRana, DeepakPandey, Anant
As per metaphor, “The squeaky wheel gets the grease,” and in the case of Battery Electric Vehicles (BEVs), the transmission system has become the focal point for NVH (Noise, Vibration, and Harshness) improvements. With the engine being replaced by the near-silent electric motor, the noise generated by the transmission has become more prominent, demanding greater attention to noise reduction. This shift has created a pressing need for innovations in both design and manufacturing processes to enhance the overall quietness of the vehicle. As a result, ongoing advancements are being made to address and improve the NVH characteristics of BEV transmissions. Following paper will discuss the improvement in NVH achieved through a design innovation in the way bearings are installed and demonstrated a significant amount of improvement. We have used SMT MASTA as a simulation tool to predict the expected results and a Transmission Dyno test bench in an anechoic chamber to test the NVH performance
Pingale, AbhijeetSoni, Jaldeep
For electric vehicles, it is critical to develop drive units that produce a minimal amount of noise while meeting efficiency needs for a given application. Modern computational resources and accumulated experience allow for engineers to evaluate gear noise early in the development process and influence the design of the drive unit. This paper documents a high-fidelity virtual engineering approach to evaluate gear noise in a concept parallel axis drive unit and provide learnings to influence the design of external structures to improve NVH performance. By using the latest simulation tools to calculate and visualize the noise and vibration characteristics of the drive unit, designers and developers can implement design changes in optimization iterations to reduce noise and vibration. Gear harmonic response is firstly analyzed through a system model which considers structural deflection and misalignment, then a FE housing model is incorporated which is used for noise radiation evaluation
Lima, LuizShi, ZhenghongXu, HaiReynolds, CraigMiller, John
Gear whine has emerged as a significant challenge for electric vehicles (EVs) in the absence of engine masking noise. The demand from customers for premium EVs with high speed and high torque density introduces additional NVH risks. Conventional gear design strategies to reduce the pitch-line velocity and increase contact ratio may impact EV torque capacitor or its efficiency. Furthermore, microgeometry optimization has limited design space to reduce gear noise over a wide range of torque loads. This paper presents a comprehensive investigation into the optimization of transfer gear blanks in a single-speed two-stage FDW electric drive unit (EDU) with the objective of reducing both mass and noise. A detailed multi-body dynamics (MBD) model is constructed for the entire EDU system using a finite-element-based time-domain solver. This investigation focuses on the analysis and optimization of asymmetric gear blank design features with three-slot patterns. A design-of-experiment (DOE
He, SongBahk, CheonjaeLi, BoDu, IsaacPatruni, Pavan KumarBaladhandapani, Dhanasekar
The use of plastic gears has expanded due to their lightweight properties, low noise emission, and cost-effective manufacturing. For instance, in the transportation equipment industry, some metal gears are being replaced with plastic gears. To achieve further size and weight reduction, gears must be able to withstand higher loads without damage. Gears have various modes of damage. Since there are different types of wear, each with different factors, it is important to identify the factors and take appropriate countermeasures. In gear meshing, there are many factors that affect wear, so restricted-factor tests are required to confirm the effectiveness of countermeasures. The purpose of this study is to elucidate the wear regime in high-load gear meshing and then to establish a simplified evaluation method replicating the meshing of gears for wear resistance focusing on the relative sliding between the two surfaces of metal and plastic. In the evaluation, changes in wear morphology over
Yamamoto, JimpeiSuzuki, TakaharuAko, NatsukiIwasaki, ShinyaKurita, Hirotaka
In recent years, accurate gear processing is required for various products to improve efficient power transmission and small noise and vibration. On the other hand, the accuracy tends to be worse by high speed processing for increasing production efficiency. Therefore, we investigated relationship between gear honing machine vibration and the accuracy. The vibration acceleration of the honing machine was measured at various conditions, and the gear accuracy was measured after processing. As results, the accuracy was observed to be affected by both the original gear accuracy before honing processing and the gear secondary rotational vibration of the machine in operation. Subsequently, we applied transfer path analysis (TPA) to investigate which directional force in operation increased the vibration. As the results, the contribution from the input force at gear processing point along normal direction was the main contributor. Then, vibration transmission characteristics of the machine
Hanioka, HiroakiOgawa, YunosukeYoshida, JunjiOnishi, YoichiKurokawa, Yasuhiro
This paper explores methods to enhance the sound quality of V6 outboard engines. Previous research in the boat and outboard engine domain has underscored the importance of enhancing sound quality. Specific preferences and desired directions for outboard engine sound quality have been identified. It’s been suggested that controlling intake sound and gear noise is important to achieving desired sound quality according to customer preferences. However, there are few examples of methods for achieving this. This study aims to develop methods for enhancing sound quality by emphasizing low-frequency sounds through intake sound. Initially, various methods were evaluated, and intake valve timing modification was chosen. Simple simulations confirmed that delaying valve timing for some cylinders may introduce characteristics that are not present in conventional cases. Subsequent 1D simulations identified optimal intake valve timing, balancing intake pressure characteristics and horsepower
Muramatsu, HidetaMatsumoto, TaroNaoe, GakuKondo, Takashi
This paper initially delineates the control process of driver-initiated gear changes. The gear-shifting point control module computes the new target gear based on the current updated driving state, and the gear-shifting point decision module assesses the rationality of the new target gear and conveys it to the gear-shifting timing control module. The gear-shifting timing control module selects the reasonable new stage in accordance with the current execution status and outputs the new target gear, coordinating the clutch control module and the brake control module to regulate the clutch engagement/disengagement and the switches of the two clutches. Altering the intention regarding gear changes encompasses gear replacement and variations in power type, which involve the necessary recalculation of the target speed based on the new target gear. Secondly, the conditions for the “change of mind” request in the speed stage are stipulated, which is the stage where the input shaft speed is
Jing, JunchaoHuang, WeishanLi, DongfeiZuo, BotaoLiu, Yiqiang
This study presents a sophisticated approach to accurately estimating the power losses in the electric vehicle drive unit (e-DU) through a combination of 1D analytical models and 3D computational fluid dynamics (CFD). Understanding and accurately estimating these power losses is crucial for enhancing efficiency and range of electric vehicles (EV). The primary focus is on the types of power losses attributable to mechanical contact friction and oil drag within components such as gear meshes, bearings, and seals. The research specifically examines different analytical models for quantifying power losses due to gear mesh contact and bearing friction. These models were validated against experimental test data, allowing for a comprehensive understanding of their accuracy across a range of operational parameters. Additionally, the impact of oil properties and oil jet flow rates on power losses related to gear and bearing drag was analyzed using analytical methods and correlated with CFD
Motin, AbdulGanamet, Alain
This paper delineates a shift control approach for a dual motor structure incorporating a drum-type shift lever in a parallel mode, which can be approximately categorized into five stages. In the first stage, the torque of the dual motor and internal combustion engine is interchanged, and the engine side torque is reverted to zero within the capacity range, with the P3 motor compensating for the torque loss on the engine side. In the second stage, the vehicle control unit transmits a request for series connection to the powertrain control module and dispatches a request for the internal combustion engine gear position to be in neutral to the powertrain control module. The powertrain control module enters the sequence for the transition from parallel to series and undertakes the action of unloading the C0 clutch torque. Once the C0 clutch torque is completely disengaged, the actual mode is fed back as parallel, and the actual engine gear position is fed back as neutral. In the third
Jing, JunchaoLiu, Yiqiangli, DongfeiZuo, BotaoHuang, Weishan
The applications are too numerous to list in their entirety. Coffee grounds. Eggshell waste. Pomegranates and pineapples. Manure and paper mill sludge. Tobacco. These are just a few of the materials that require dewatering, a process that — as its name suggests — separates fluids from solids, often converting what would otherwise go down the drain or end up in a landfill into saleable products.
This study introduces a probabilistic analysis approach to evaluate the gear tooth strength for the hypocycloid engines, which are particularly significant in internal combustion (IC) engine applications due to their unique design and critical requirements for both efficiency and durability. The research utilizes the stress–strength interference (SSI) theory within a “design for reliability” framework to develop a robust methodology for designing the internal gear mechanism required for the hypocycloid gear mechanism (HGM) engine, in accordance with American Gear Manufacturers Association (AGMA) standard gear rating practices. This approach incorporates probabilistic factors to address variations in HGM component parameters, gear material properties, and engine operational conditions. To validate the design and ensure accuracy, a finite element method (FEM)-based verification is employed, to identify potential failure points and enhance the overall reliability of the HGM engine. The
ElBahloul, Mostafa A.Aziz, ELsayed S.Chassapis, Constantin
Electric vehicles (EVs) are paving the way for future mobility, with drive motors playing a central role in their efficiency and performance. Motor testing machines are crucial for validating EV motors, yet flaws in testing equipment, such as gear issues, often lead to operational disruptions. This study aims to enhance motor testing by implementing machine learning and vibration signal analysis to detect gear faults early. Using statistical feature extraction and classifiers like Quadratic SVM and Bagged Trees, the collected vibration signals are categorized as normal or faulty under loaded (0.275 kW) and no-load conditions. Performance comparison reveals the Bagged Trees algorithm's superior accuracy of 95.3%. This approach offers an intelligent, preventive maintenance solution, improving the motor test bench’s reliability.
S, RavikumarSyed, ShaulV, MuralidharanD, Pradeep Kumar
In Electric vehicle Drive Unit Gears, high mesh misalignments result in shift in load distribution of a gear pair that can increase contact and bending stresses. It can move the peak bending and contact stresses to the edge of the face width and increase gear noise as well. Lower misalignment value is often required to reduce the peak bending and contact stresses and have a balanced load distribution along the gear flank, which in turn helps in reducing noise and improving durability of drive unit. This paper delineates Prescriptive Analytics method that combines virtual simulations, Machine learning (ML) and optimization techniques to minimize different gear misalignments for the electric vehicle drive units. Generally, the manual optimization process is carried out by sequential modifications of stiffness of individual components. However, this process is time consuming and does not account for interactions between the components. In this study, firstly, Machine learning models are
Penumatsa, Venkata Ramana RajuThomas, BensonBlack, DerrickJain, Sachin
Due to manufacturing, assembly, and actuator wear, slight deviations between the actual and logical positions of various gears in a transmission system may accumulate, affecting shift quality, reducing shift accuracy, and causing operational anomalies. To address this issue, a self-learning method based on the top dead center (TDC) and lower dead center (LDC) was proposed, specifically for the hybrid gearbox of an electric torque converter (eTC) module and a double-input shaft gearbox (DIG). The linear active disturbance rejection control (LADRC) method was employed to estimate and manage the nonlinear resistance during the motion of the shifting motor. To simplify the controller parameter problem, the nutcracker optimization algorithm (NOA) was utilized to tune the LADRC parameters, thereby optimizing the position self-learning process. The control strategy was modeled using MATLAB/SIMULINK, and its reasonableness was verified through hardware-in-the-loop (HIL) tests. Based on these
Hong, HanchiQuan, Kangningd’Apolito, LuigiXu, Li
Organizations need to maintain their processes at high levels of efficiency to be competitive, asset management and industrial maintenance are extremely important to obtain positive results in optimizing operating costs, saving energy resources, reduction of environmental impacts among other characteristics that are considered differential for organizations. In this scenario, methods are increasingly being sought to assist managers in decision-making processes that contain several alternatives and selection criteria involved. The AHP and TOPSIS methods have been widely associated with prioritization studies, cost evaluation, resource selection, suppliers, among others. Thus, the selection of equipment and industrial elements can be evaluated by means of multicriteria decision methods where the criteria considered important by specialists in the area are inserted into the model. The objective of this article was to present a selection process for spur gears based on stress analysis and
de Oliveira, Geraldo Cesar Rosariode Oliveira, Vania Aparecida RosarioSilva, Carlos Alexis AlvaradoGuidi, Erick SiqueiraSalomon, Valério Antonio PamplonaRosado, Victor Orlando Gamarrade Azevedo Silva, Fernando
This paper proposes a theoretical drive cycle for the competition, considering the battery pack project under design. The vehicle has a non-reversible, double-stage gear train, created without a dynamic investigation. To evaluate the effect on performance, several ratios were analyzed. Dynamic model uses Eksergian’s Equation of Motion to evaluate car equivalent mass (generalized inertia), and external forces acting on the vehicle. The circuit is divided into key locations where the driver is likely to accelerate or brake, based on a predicted behavior. MATLAB ODE Solver executed the numerical integration, evaluating time forward coordinates, creating the drive cycle. Linear gear train results provided data as boundary conditions for a second round of simulations performed with epicyclic gear trains. Model is updated to include their nonlinearity by differential algebraic equation employment with Lagrange multipliers. All data undergoes evaluation to ascertain the mechanical and
Rodrigues, Patrícia Mainardi TortorelliSilveira, Henrique Leandro
Gear shifting performance in vehicles is critical for smooth operation, especially under cold environment conditions or sub-zero conditions. In this comprehensive study, we delve into the multifaceted aspects that influence gear shifting behaviour during cold conditions especially after overnight vehicle soaking at low temperature below -8°C to simulate real world scenarios. Notably, our efforts on these bench trials focuses on isolating the synchronization load from the maximum block release force, a phenomenon arising from the interaction between synchronizer rings and gear cones in case of high drag of input and counter shafts. Our experimental trials involved multiple bench level testing for lower gear shifting case especially 2nd to 1st gear and 1st to 2nd gear shifting. Factors under study are focusing on changing the Oil (viscosity and quantity), different combination of synchronizer ring material, change of inertia etc. Shifting load in cold condition mainly includes two loads
Mishra, SubodhSiddharth, KumarSingh, Manoj
Gear shifting effort or force especially in manual transmission has been one of the key factors for subjective assessment in passenger vehicle segment. An optimum effort to shift into the gears creates a big difference in overall assessment of the vehicle. The gear shifting effort travels through the transmission shifting system that helps driver to shift between the different available gears as per the torque and speed demand. The shifting system is further divided into two sub-systems. 1. Peripheral system [Gear Shift Lever with knob and shift Cable Assembly] and Shift system inside the transmission [Shift Tower Assembly, Shift Forks, Hub and sleeve Assembly with keys, Gear Cones and Synchronizer Rings etc.] [1]. Both the systems have their own role in overall gear shifting effort. There has been work already done on evaluation of the transmission shifting system as whole for gear shifting effort with typical test bench layouts. Also, work has been on assessment of life of the
Singh, ParamjeetYadav, Sanjay Kumar
Integrated electric drive systems are characterized by high power density, reliability, and controllability, making them increasingly prevalent in the realm of electric commercial vehicles. However, the direct coupling between the motor shaft and the transmission system has introduced a series of undesirable torsional vibration phenomena. To investigate the dynamic characteristics of electric drive systems in operation for electric commercial vehicles, a comprehensive modeling approach is employed. This modeling framework takes into account key factors such as gear backlash, structural flexibility, and electromagnetic spatiotemporal excitations. Based on this model, the influence of the electrical system on time-varying gear mesh stiffness, gear transmission error, bearing forces, and other factors is investigated. Building upon this foundation, the article proposes an approach for active harmonic voltage injection. This method effectively reduces torque fluctuations, decreases the
Xi, XinChen, XiaoliZhao, HongyangZhao, XuanWei, JingLiu, Yonggang
This paper evaluates electric machine and reducer specifications along-side vehicle dynamics and drivability for an axial flux machine (AFM). The baseline is a conventional central drive unit with a single electric machine, reducer, and differential. It compares powertrain architectures with two in-wheel AFMs (IWD) and one AFM mounted perpendicular to the chassis against the E-Axle design. The study starts by determining wheel-level traction force and power requirements for a mid-sized vehicle, then derives necessary machine and reducer specifications. It also considers packaging and efficiency constraints. The E-Axle uses a single-stage planetary gearbox, while the perpendicular AFM connects to a bevel gear reducer, and the IWD requires no reducer. These architectures are analysed in a vehicle dynamics simulation with six degrees of freedom, suspension, tire, and road models. Efficiency is assessed using the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). Besides acceleration
Wipfler, FelixYildirim, MetinNegrila, Andrei-RaduGerling, DieterBruell, MartinSabzewari, Kiarash
A power steering system helps the heavy-duty operator move the vehicle easily with the hydraulic pump that provides the fluid pressure and facilitating adequate operation. Some failures in the power steering system are due to external and internal factors that can reduce its service life. The external factors could be identified by ocular inspection but normally, due to internal failures, it is necessary to use a hydraulic pressure flow meter. However, this device makes it impossible to detect failures caused by the selected lubricant. This work aims to investigate the causes of power steering system seizure by using the tribological wear examination process and the lubricant characterization under some actual operation conditions. The lubricant characterization was carried out in a four balls tester using fresh and used samples of a re-refined oil based ATF, SAE 15 W40 and synthetic SAE 5 W30 oils at two temperatures. In general, the results showed an unsteady friction profile with
García-Maldonado, MiguelGallardo, EzequielMozqueda-Flores, LuisVite-torres, Manuel
Geared automotive and aerospace transmissions are one of the most critical systems regarding wear. Limiting wear is of paramount importance to improve sustainability by reducing replacements that lead to increased waste and energy consumption for re-manufacturing. Simulation of gears including the wear effect can be very useful for the design of new more efficient and compact gears. Thermal effects may play a decisive role in the wear phenomena and should be included in the models used for simulations. In this study, some tests are conducted on a pin-on-disk apparatus under varying temperatures to assess its influence on steel-to-steel wear rate. A modified Archard law is used for wear estimation which includes the experimentally derived parameters accounting for thermal effects. This model is then coupled with a loaded tooth contact analysis (LTCA) tool to obtain accurate predictions of the contact pattern, as well as the instantaneous load shared by the mating teeth pairs during the
Grabovic, EugeniuCiulli, EnricoArtoni, AlessioGabiccini, Marco
Rolling bearings play a critical role in rotating machinery, with their fatigue life directly impacting equipment’s operational reliability. This underscores the significant engineering application value of “fault diagnosis” (FD) technology for rolling bearings in mechanical, automation, and aerospace domains. Literature reviews highlight that a substantial portion of failures in machinery such as jet turbine engines, wind turbines, gear reducers, and induction machines are attributable to bearing issues. Early fault detection and preventive maintenance are therefore imperative for ensuring the smooth operation of rotating machinery. This paper focuses on rolling bearings, delving deep into FD technology using machine learning principles. It analyses the structure and common failure modes of rolling bearings, discussing an FD method based on machine learning. Specifically, the SE-DRN (“squeeze-exclusion deep residual network”) approach is employed, leveraging “variational modal
Muin, Abdullah-AlKhan, ShahrukhMiah, Md Helal
As environmental concerns have taken the spotlight, electrified powertrains are rapidly being integrated into vehicles across various brands, boosting their market share. With the increasing adoption of electric vehicles, market demands are growing, and competition is intensifying. This trend has led to stricter standards for noise and vibration as well. To meet these requirements, it is necessary to not only address the inherent noise and vibration sources in electric powertrains, primarily from motors and gearboxes, but also to analyze the impact of the spline power transmission structure on system vibration and noise. Especially crucial is the consideration of manufacturing discrepancies, such as pitch errors in splines, which various studies have highlighted as contributors to noise and vibration in electric powertrains. This paper focuses on comparing and analyzing the influence of spline pitch errors on two layout configurations of motor and gearbox spline coupling structures
Park, SoheeMin, Gyeonghwi
For a couple of decades, virtually every global original equipment manufacturer spent significant capital and attention raising their sales/production profile in China. It became the world's largest light vehicle market by 2010 and has not looked back. Forming new joint ventures to expand their portfolios through the extension of global offerings, several OEMs even took the opportunity to design China-specific variants. Western OEMs followed these JVs, and scores of European, North American, Japanese and Korean Tier 1 and 2 suppliers followed their OEMs, creating a local supply of global components as China became an integral cog in the machine. A presence in China is core to success for many industry players. China produced about 28 million light vehicles in 2023, based on S&P Global Mobility's estimates. China is not only key for Western OEM profitability, from a volume perspective it is the largest single market (about 31% of the world in 2023) with the highest growth profile. It
An advanced multi-layer material model has been developed to simulate the complex behavior in case-carburized gears where hardness dependent strength and elastic-plastic behavior is characterized. Also, an advanced fatigue model has been calibrated to material fatigue tests over a wide range of conditions and implemented in FEMFAT software for root bending fatigue life prediction in differential gears. An FEA model of a differential is setup to simulate the rolling contact and transient stresses occurring within the differential gears. Gear root bending fatigue life is predicted using the calculated stresses and the FEMFAT fatigue model. A specialized rig test is set up and used to measure the fatigue life of the differential over a range of load conditions. Root bending fatigue life predictions are shown to correlate very well with the measured fatigue life in the rig test. Also fatigue life predictions are shown to correlate well with validation tests carried out on a full-scale axle
DeJack, Michael A.Tichy, Richard
Through real-time online optimization, the full potential of the performance and energy efficiency of multi-gear, multi-mode, series–parallel hybrid powertrains can be realized. The framework allows for the powertrain to be in its most efficient configuration amidst the constantly changing hardware constraints and performance objectives. Typically, the different gears and hybrid/electric modes are defined as discrete states, and for a given vehicle speed and driver power demand, a formulation of optimization costs, usually in terms of power, are assigned to each discrete states and the state which has the lowest cost is naturally selected as the desired of optimum state. However, the optimization results would be sensitive to numerical exactitude and would typically lead to a very noisy raw optimum state. The generic approach to stabilization includes adding hysteresis costs to state-transitions and time-debouncing. These added costs could result in systems remaining in sub-optimal
Kudupley, HarshalMawardi, AndryasPatel, Nadirsh
With the advancement of regulatory norms in automobile industry, there is a challenge to meet performance efficiency targets, especially with a lightweight platform, while providing superior driving experience to customers. The shift towards weight optimization, makes the vehicle structure more susceptible to transfer a diverse range of noise and vibrations through body. Although most undesirable noises perceived inside the cabin can be reduced by superior technology engine mounts and NVH packaging, all such solutions lead to cost addition. Intelligent considerations in part design can be used to supplement predictable transfer paths to quell the unwanted vibrations. One such case is of the gear whine noise in certain rpm bands caused by inherent gear meshing frequency coinciding with natural frequency of an engine mounting bracket. This paper demonstrates two methodologies to counter such a phenomenon, either through engine mount bracket natural frequency optimization or addition of a
Ghosh, ChiranjitAgrawal, AdheeshKarmakar, SudiptoSrivastava, ShubhamKhan, Aamir
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 engine 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. Paper focuses on simulation of gear impact power and its sensitivity to transmission shaft deflections. Impact power is one of the indicators of transmission rattle noise and transmission shaft deflection is one of the contributors for gear impact power. 3D MBD simulations are carried out to calculate loose gear impact power by applying angular acceleration input to
Bijwe, Vilas B.Kulkarni, ShriramVaidya, RohitShah, Bhartendra
Climate change due to global warming are major concerns. Electric vehicles are one of the promising technologies to curb the climate change by reducing CO2 emissions significantly. Electric vehicle component selection is a complex process, which has to fulfil multiple requirements with trade-off between performance & efficiency, efficiency & cost, performance & NVH, packaging & performance etc. In addition, E-drive selection in passenger & commercial vehicle is different due to application difference. Hence, it is a great challenge to select right E-Drive comprising motor, MCU and overall gear ratio to meet EV program constraints and targets. This study focuses on criterion used for selecting an E-Drive system comprising motor, MCU and overall gear ratio for electric vehicles in commercial and passenger vehicle segments. The automotive market in India is analysed and the most popular vehicles in CV and PV segments with comparable kerb weights have been identified; small commercial
Jadhav, Vaibhav V.Shendge, Raman S.Warule, Prasad B.Wani, Kalpesh S.
Worldwide automotive sector regulatory norms have changed and become more stringent and complex to control environmental noise and air pollution. To continue this trend, the Indian Ministry of Road Transport is going to impose new vehicle exterior pass-by noise regulatory norms IS 3028:2023 (Part2) to control urban area noise pollution. This paper studies the synthesis of M1 category vehicle driving acceleration, dominant noise source, and frequency contribution in exterior PBN level. A vehicle acceleration analysis study was carried out to achieve an optimized pass by noise (PBN) level based on the vehicle’s PMR ratio, reference, and measured test acceleration data. Based on the analysis, test gear strategy was decided to achieve a lower PBN level. This strategy involved increasing the effective final drive ratio and optimizing engine calibration, resulting in improvement with acceleration in the ith gear. This increased acceleration surpassed the upper limit of the reference
Kalsule, Shrikant BalasahebTitave, UttamPatil, JitendraJadhav, KamalakarNaidu, Sudhakara
Increased popularity on SUV category in the market has led to high focus on performance attributes of SUVs. Considering high weight & CoG achieving target handling performance is always a challenge. Static Wheel Alignment parameters, especially Camber have shown significant contribution in Handling attributes of vehicle. This paper presents an experimental study on change in wheel camber under the influence of different vehicle loading conditions. In SUVs, generally wheel is subjected to large deflection from its high static loads which makes it quite difficult to maintain an ideal camber angle. Hence, it is important to analyze the camber angle variations under actual loading conditions. An in-house fixture is developed to emulate the actual vehicle loading conditions at rear wheel end. The multi-link rigid axle suspension with watt’s link assembly is mounted on the chassis-frame which is rigidly fixed to ground, and loads are achieved through hydraulic actuators at Wheels. Axle
Jani, HarshilRasal, ShraddheshHussain, InzamamAsthana, ShivamAhire, ManojVellandi, VikramanSenniappan, Moorthy
The commercial vehicles market is dominated by manual transmission, due to lower ownership cost. Generally, 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, driver fatigue can be reduced with a smooth gear change process. The gear change process in a manual transmission is carried out with the help of the synchronizer pack. The crucial function of a 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 the 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 is very uneven and
Jamadade, GajananK, Barathi RajaChatterjee, Soumik
As a car OEM, we continuously strive to set the bar for competitors with every product. Consumer travel experiences are enhanced by increasing passenger cabin silence. There is only one steering system opening in the firewall panel, which is used for allowing intermediate shaft's fitment on the pinion shaft of the steering gear. The steering grommet is the sole component that covers the firewall cut-out without disrupting steering operations, which has a substantial impact on the NVH performance of the vehicle. It is typically used in cars to eliminate engine noise and dust entering to passenger compartment. The part is assembled inside the vehicle where the steering intermediate shaft passing through BIW firewall panel. We use a bearing, plastic bush, or direct rubber interference design in the steering grommet to accommodate the rotational input the driver provides to turn the automobile. However, occasionally noise may be produced due to uneven bearing or plastic bush loading or a
J, SadhishVijayarangan, DeepakS, SenthilKole, Shantinath
The automotive industry has recently started implementing magnetic gears, in different types, as an alternative design for transmission systems. One such design being the Magnetic planetary gear permanent magnet (MPG-PM) machine. The current methodology and the relevant formulae help to design the magnetic planetary gear system, which does not have design considerations for permanent magnet machines and the influence of magnetic fields. The influence of design characteristics of PM machine, Magnetic field and its material plays a vital role in designing the MPG-PM for electric vehicle applications. A method of optimizing the Gear topology design parameters of a magnetic planetary gear permanent magnet machine (MPG-PM machine) is proposed. The Analytical calculations regarding the design parameters are proposed in relation to power, gear ratios, and other design constraints like packaging parameters i.e., outer diameter, the overall length of the machine. The analytical calculation
Ramakrishnan, Gowtham Raj
This paper discusses the overall design and development of Rack and pinion steering (RPS) gear assembly in terms of gear calculations, DVP, modeling, performance characteristics, strength analysis and physical testing. Design calculations for gear meshing included several parameters like normal module, transverse module, helix angle, no. of teeth as per steering gear ratio, pinion shaft angle etc. A complete geometry of the RPS gear assembly was developed using CAD software UG-NX as per vehicle requirements. BIW(Body in white)and its surrounding parts clearance from the RPS assembly were verified for packaging review. Performance study of the assembly includes simulation-based prediction using MSC Adams for estimation of various output parameters like free pinion Torque and its variations over rack travel, rack force required for rotating pinion, gear ratio, relation between input torque of pinion and output load to find rack efficiency. Strength tests of the assembly are done to find
Rathore, Gopal SinghChawla, Shubham
Advent of EV powertrain has considerable effect on transmission development activities as competed to regular ICE transmission. Conventional ICE transmission and the transmission for an e-powertrain differ on fundamental level. The conventional transmission has number of gear ratios, shift mechanism which enables the transmission to deliver a smooth power output as per demand from the driver. Whereas the e-powertrain transmission is mostly a single gear ratio transmission (reducer) which primarily depends on speed and torque variation from the motor to cater the driver requirement. Hence, the operating speeds of such e-transmissions can vary from 0 to 20000 rpm in both forward and reverse directions. Such a large speed variation as compared with conventional transmission calls for special attention towards the lubrication of internal components. High speeds and lower oil viscosities tend to disrupt the oil films in between contact surfaces causing metal to metal contact. This situation
Kushwaha, RakeshBhosale, VikasNavale, PradeepPatel, Hiral
Gear vibration and noise evaluation approaches are commonly proposed with a variety of way in a transmission system while complicated and obscured, it is difficult to provide a feasible basis for the gear development of E-drive system. Based on the vibration mechanism of E-drive gear meshing and order tracking theory on rotating machinery, this paper expressed the details of gear vibration evaluation approach accordingly during E-drive system’s development phase, combined with objective testing and subjective evaluation correlation analysis, raised the meshing gear order vibration evaluation approach by the means of the testing data target curve-fitting, also verify the reasonableness and validity of this approach on a HEV matched with E-drive system by means of subjective evaluation and objective measurement before and after the gears’ optimization, the clarification shows that significant correlation between subjective evaluation and objective measurement of the meshing gears both of
Jing, HaihongDeng, FengZhang, NiWang, XichengWu, XiaolongWang, Yiping
The brass synchronizers are not resistant to abusive conditions of gearbox operations, but they are very durable and cheap when used on their favorable material property working limit. The main failure which can occur in the gearbox due to the synchronizer is crash noise. During gear shifting the gear crash will create high discomfort for the driver and must apply high force to change the gears. The main factors which contribute to the crash phenomenon are the insufficient coefficient of friction, high drag in the system, and high wear rate of the synchronizer rings before the intended design life of the synchronizer. The brass synchronizers were tested on the SSP-180, ZF synchronizer test rig to know the effect of the synchronizer performance parameters like the coefficient of friction, sleeve force, slipping time as well as durability parameters like wear rate when the operating temperature of the oil is changed. This study will help to predict the impulse behavior, surface pressure
K, Barathi RajaKumar, Aneesh
Manual transmission (MT) is still the most preferred solution for emerging markets due to the lower cost of ownership and maintenance coupled with a higher transmission efficiency. In this regard, continuous improvement of the transmission shift quality is quite essential to meet the growing customer expectations. In the present work, a detailed evaluation of the gear-shift impulse (experienced at the gear-shift knob) is conducted between two different architectures of a manual, high-torque (450 Nm input torque) inline transmission meant for a sports utility vehicle (SUV). The conventional manual inline transmission architecture comprises a common gear pair at the input of the transmission. While this input reduction architecture is the most widely used architecture, having the common gear pair at the output of the transmission is also another option. The synchronizers of the manual transmission need to match the speed of the rotating components just before the gear-shifting event. The
K, Barathi RajaKumar, AneeshR, ManikandanOstwal, Amit
Gears are one of the vital components to transmit torque efficiently. Helical gears are chosen as they transmit higher torque with lesser noise compared to spur gears of same size. All new age gearboxes require to transmit maximum torque with minimum packaging space available to improve torque density. Ways of reducing weight are using lesser density material, decreasing centre distance, and thereby reducing pitch circle diameter of all gears, etc. However, they will also affect torque carrying capacity of gearbox which can lead to gear failure in conventional transmission architecture gearboxes with input reduction method. In input reduction method, torque gets multiplied from input shaft to countershaft. Countershaft torque is multiplied to output shaft gears requiring higher torque capacity gears on output shaft. In this research, output shaft reduction architecture is proposed to avoid torque multiplication from input shaft to countershaft gears. It helps to reduce gear sizing on
R, ManikandanK, Barathi RajaKumar, AneeshOstwal, Amit
NASA intended its Reusable Launch Vehicle program of the 1990s to demonstrate technologies that would enable hypersonic spaceplanes to make affordable, repeated trips into space. It was never intended to improve the performance of hunting, skiing, and sports gear, but, more than 20 years after its cancellation, that’s what’s happened.
Integrating sensors into rotational mechanisms could make it possible for engineers to build smart hinges that know when a door has been opened, or gears inside a motor that tell a mechanic how fast they are rotating. MIT engineers have now developed a way to easily integrate sensors into these types of mechanisms, with 3D printing.
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