Browse Topic: Bearings

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Design considerations for optimizing the wheel bearing outer ring bolt‑mounting pattern for reduced drag2026-01-0830To be published on 09/14/2026
Electric vehicles (EVs) place unique and demanding requirements on wheel bearing systems due to their increased vehicle mass, higher torque output, and the need for improved energy efficiency to maximize driving range. These factors elevate the loads transmitted through the bearing‐to‐knuckle joint, often necessitating higher clamp loads to maintain joint integrity. However, increased clamp loads can amplify wheel bearing outer ring distortion, leading to higher rotational drag and reduced bearing durability. Managing and minimizing outer ring distortion is therefore critical for EV wheel bearing design, as well as for high‑performance vehicles that experience extreme lateral loads at the hub‑to‑knuckle interface. This paper investigates key design considerations for optimizing the wheel bearing outer ring and its mounting interface to minimize distortion under elevated clamp loads. A comprehensive CAE‑based Design of Experiments (DOE) is conducted to evaluate the influence of various
Mandhadi, Chaitanya Reddy, Lee, Seungpyo, Bovee, Benjamin, Callaghan, Kevin
Influence of Scrub Radius on Steering Dynamics, Bearing Durability and Wheel-End Packaging in Heavy Commercial Vehicles2026-01-0831To be published on 09/14/2026
Front axle geometry is a critical determinant of vehicle performance in heavy commercial vehicles (HCVs), directly influencing steering feel, component life, and maintenance costs. This paper investigates the effects of increasing scrub radius—defined as the lateral distance between the tire contact patch center and the steering axis intersection with the ground—on steering dynamics, durability, and packaging. A larger kingpin offset generating a positive scrub radius improves steering leverage and reduces steering torque, particularly beneficial for power-assisted steering systems. However, its broader implications for wheel-end design require detailed evaluation. High-fidelity multi-body dynamics models, validated through instrumented vehicle testing, were employed to quantify these effects under diverse scenarios, including low-speed maneuvering, high-speed lane changes, and severe braking. Results indicate that a controlled increase in scrub radius (10–20 mm) reduces steering
Pandiyan, Mahendran, Saxena, Saurabh
Analysis of the Cause of Knocking Noise in a Marine Dual-Power Dual-Branch Transmission Gear System2026-99-1650To be published on 07/24/2026
This study investigates the knocking noise phenomenon in a marine dual-power dual-branch transmission gear system. Vibration mechanisms are analyzed, and potential failure modes are assessed. System vibration data were evaluated using time-domain and frequency-domain methods. Results show that overall vibration levels remained within acceptable limits, with no indication of imminent failure. Physical inspection confirmed that the shaft, gears, bearings, housing, and installation met specifications, with no observed performance degradation or structural damage. By correlating noise occurrence with vessel loading conditions, a strong relationship was identified among gear transmission torque, the power distribution ratio between high-and low-pressure turbines, and the onset of knocking. Specifically, under low-load conditions, uneven power and torque distribution among the four gear branches led to insufficient loading on the low-pressure side. This light-load state induced instability
Gu, Chengzhong, Xu, Hanwei, Luo, Rirong, Ren, Fushan
Evaluation of Structural Service Performance of Low-temperature Modified Asphalt Pavement based on Peavy-Duty traffic Engineering2026-99-1645To be published on 07/24/2026
Relying on the reconstruction project, the low-temperature modified asphalt pavement significantly reduces the construction temperature of the asphalt mixture by 40 °C compared with the traditional asphalt pavement, and improves the road performance of the material. By comparing the two mixture rolling schemes, the compaction effect of scheme 2 is better. For AC-13 mixture, the flexural tensile strength of USP-SBS composite modified asphalt mixture is 0.67 MPa higher than that of SBS modified asphalt mixture, and compared with SBS modified asphalt mixture, the final rut depth of USP-SBS composite modified asphalt mixture is 2.68 mm shallower than that of SBS modified asphalt mixture, and the total deformation rate is 43.8% lower than that of the latter. The post-construction quality evaluation shows that the stability of the low-temperature modified asphalt pavement test section under the bearing capacity and high-temperature-water coupling is better than that of the conventional road
Liu, Chuanfeng, Xu, Ke, Shi, Zheng, Hao, Jidong, Zhao, Liandi, Xianwei, Wang
Adaptive Class-Incremental Learning Intelligent Fault Diagnosis Method for Unmanned Aerial Vehicle Rolling Bearings2026-99-05967/10/2026
As a key component of unmanned aerial vehicles (UAVs), the stable operation of motor bearings is of vital importance to the stability of UAVs. In view of the incomplete data set in the actual diagnosis process, samples not encountered during model training are highly likely to appear. This paper proposes an Adaptive Class-Incremental Learning(ACIL) intelligent fault diagnosis method. This method construct a ResNet framework embedded with Coordinate Attention as the base architecture for class-incremental learning. Furthermore, the Information Preservation Example Selection(IPES) method is utilized to alleviate catastrophic forgetting and update the model from the previous phase using knowledge distillation under coordinate attention. The effectiveness of this method is verified through experiments on the bearing test dataset. The results show that, both average incremental accuracy and average incremental forgetting rate achieve state-of-the-art performance, which means that the
Song, Ziyang, Lu, Jiantao, Wu, Wei, Li, Shunming
A Novel Rotating Component Comprehensive Diagnostic Network Based on Stacked Auto Encoders and Sparse Filter Combined with Generative Adversarial Network2026-99-05347/10/2026
Nowadays, the majority of intelligent fault diagnosis approaches are still centered on individual faulty components, while only a limited number of models are capable of performing integrated diagnosis for rotating systems that consist of shafts, bearings, and gears. Under variable-speed operating conditions, the large scale of vibration data further complicates the process of effective feature extraction. To improve these challenges, this study develops a comprehensive diagnostic framework for rotating components, termed WGAN-SAFC. The proposed architecture integrates a Wasserstein Generative Adversarial Network (WGAN) with a hybrid structure of stacked autoencoders and sparse filtering (SAFC). SAFC integrates the feature-learning capability of SAE and the sparsity-driven representation of SF, while incorporating adversarial data generation to address sample imbalance and enhance fault diagnosis performance. Experimental verification on collected vibration datasets demonstrates that
Li, Shunming, Feng, Mengqi
Vibroacoustic Analysis and Optimisation of an Electric Refrigerant Scroll Compressor2026-01-07226/20/2026
In electrified vehicles, auxiliary components can represent a dominant source of noise, one of which is the refrigerant scroll compressor. Compared with vehicles equipped with internal combustion engines, electrified vehicles require larger refrigerant compressors, as thermal management is needed not only for the passenger compartment but also for the battery and electric drive components. Excitation mechanisms within the compressor, arising from the cyclic compression process and the eccentric motion of the scroll, induce housing vibrations and result in airborne sound radiation. To investigate the vibroacoustic noise generation mechanisms of a scroll compressor, operational vibrations were analysed using accelerometers and three-dimensional laser scanning vibrometry. In addition, the radiated sound was characterised using microphones and near-field sound intensity measurements. The results demonstrate a strong correlation between surface vibrations and airborne sound radiation, with
Saur, Lukas, Beer, Gabriel, Fritzsche, Marco, Becker, Stefan
Influence of Common-Mode Voltage Reduction Techniques on High-Frequency Sideband Vibrations in IPMSM Drives for EVs2026-01-06956/20/2026
Space vector pulse width modulation (SVPWM) induces common-mode voltage (CMV) in three-phase voltage-source inverters, producing steep voltage edges that can lead to high leakage currents. In electric drive applications, these currents accelerate motor bearing degradation and may cause winding insulation failure. Active-zero-state PWM (AZSPWM) and near-state PWM (NSPWM) have been proposed as alternative modulation strategies to mitigate CMV and reduce drive degradation. This paper investigates the noise, vibration, and harshness performance of AZSPWM and NSPWM in comparison with conventional SVPWM. The proposed CMV reduction schemes are evaluated in terms of both CMV mitigation and their impact on high-frequency sideband vibration harmonics. Experimental results demonstrate that the CMV reduction strategies are highly effective in lowering CMV levels relative to SVPWM; however, this benefit is accompanied by an increase in vibration levels, which may adversely affect the mechanical
Khamis, Mahmoud Aly, Tatar, Andrei Alexandru, Repecho, Victor, Doria-Cerezo, Arnau
BEARING, BALL, AIRFRAME, ANTI-FRICTION, SELF-ALIGNING, LIGHT AND HEAVY DUTYAS27645D (Current)6/18/2026
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTIFRICTION, EXTERNAL SELF-ALIGNING, EXTRA LIGHT DUTY CORROSION-RESISTANT NITROGEN STEEL (CREN)AS27648/1A (Current)6/15/2026
ACBG Rolling Element Bearing Committee
Rolling Element Bearing Axial and Radial Internal ClearanceARP5483/3B (Current)6/10/2026
This test method outlines the standard procedure for measuring the radial and axial internal clearance of rolling element bearings used in airframe controls.
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTIFRICTION, INTERMEDIATE DUTY CORROSION RESISTANT NITROGEN STEEL (CREN)AS27649/1A (Current)6/9/2026
ACBG Rolling Element Bearing Committee
Hybrid Digital Twin for Aero-Engine Bearing Prognostics: A Physics-Informed Machine Learning Approach to RUL Prediction2026-26-07186/1/2026
Unscheduled maintenance due to the failure of critical components, such as aero-engine rolling element bearings, is a leading cause of costly Aircraft-on-Ground (AOG) events; consequently, current time-based maintenance practices are inefficient and prone to risk. This paper develops a resource-efficient Hybrid Digital Twin (HDT) model for an engine bearing, focusing on the dynamic prediction of spall growth due to Rolling Contact Fatigue (RCF), thereby enabling a condition-based maintenance paradigm. The HDT architecture integrates two core models: (1) a physics-informed model that uses established life and fatigue theory to define initial degradation thresholds, and (2) a data-driven Recurrent Neural Network (RNN), specifically a Long Short-Term Memory (LSTM) network, for dynamic degradation rate modeling. The methodology utilizes a Monte Carlo simulation coupled with RCF progression equations to generate a large, high-fidelity synthetic run-to-failure dataset under varying
Mohamed, Abbas
Rolling Element Bearing Hardness TestARP5483/2B (Current)5/15/2026
This method outlines the standard procedure for testing the hardness of bearing components. Bearings covered by this test method shall be any rolling element bearing used in airframe control.
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTIFRICTION, EXTRA LIGHT DUTY, PRECISION CORROSION-RESISTANT NITROGEN STEEL (CREN)AS21428/1C (Current)5/15/2026
ACBG Rolling Element Bearing Committee
Developments in Debris Monitoring of Hybrid BearingsF-0082-2026-02645/5/2026
Hybrid bearings, which pair traditional bearing-steel raceways with ceramic rolling elements, can offer improved performance over full-metal bearings, particularly in aerospace applications. Because rolling-element bearings are critical components, effective condition monitoring is essential to prevent in-flight failures and support proactive maintenance strategies. Wear-debris monitoring is widely used in these applications to detect and diagnose bearing fault modes. To compare degradation behavior and monitoring signatures, bearing life tests were conducted on hybrid and full-metal bearings under matched Hertzian stress conditions. The results showed that differences in degradation curves between the two bearing types were small relative to the overall variability in bearing life. Additionally, hybrid bearings that develop rolling-element pitting were observed to progress toward raceway spall formation. This paper was presented at ERF Forum 51 but has been updated with new findings
Mahmoud, Hassan, Oszmian, Adam
Smart Duplex A Digital Inspection Strategy for Duplex BearingsF-0082-2026-01065/5/2026
Rolling-element bearings in rotorcraft dynamic systems are critical components susceptible to rolling contact fatigue (RCF), a dominant degradation mechanism manifesting through subsurface-initiated spalling, surface micropitting, and fatigue fractures. Robust inspection strategies compliant with EASA and FAA requirements are therefore essential. Traditional methods are often invasive, requiring disassembly, and are susceptible to human-factor errors. Smart Duplex introduces a design-for-monitoring architecture integrating in-situ videoscopic and coherence scanning interferometry (CSI) for high-resolution 3D surface mapping, including under partial grease coverage. This paper details a repeatability and reproducibility (R&R) framework ensuring metric consistency; a maintainability assessment projecting significant man-hour reductions and high availability; certification rationale emphasizing airworthiness improvements via enhanced detectability, workload reduction, and digitized
Delli Paoli, Michele, Anaclerio, Mario Alberto
WITHDRAWAL NOTICE2026-01-0158.014/7/2026
Experimental Validation of a Multi-Row Tapered Roller Bearing Analytical Model for Relating Preload to Frequency Response Characteristics2026-01-00084/7/2026
Roller bearings are used in many rotating power transmission systems in the automotive industry. During the assembly process of the power transmission system, some types of roller bearings (e.g., tapered roller bearings) require a compressive preload force. Those bearings' rolling resistance and lifespan strongly depend on the preload set during the installation process. Therefore, accurate setting of the preload can improve bearing efficiency, increase bearing lifespan and reduce maintenance costs over the life of the vehicle. A new method for bearing preload measurement has shown potential for both high accuracy and fast cycle time using the frequency response characteristics of the power transmission system. An open problem is experimental validation of the multi-row tapered roller bearing analytical model. After validation, the analytical model can be used to predict the assembled system damped natural frequency for a desired bearing preload. This work presents the experimental
Gruzwalski, David, Mynderse, James
Optimization of Lightweight Gear Blanks to Improve NVH for an Electric Drive Unit2026-01-00014/7/2026
A single-speed electric drive unit (eDU) with multi-stage reduction can have high gear whine due to high pitch-line velocity in the absence of engine masking noise. A comprehensive investigation is conducted focusing on the optimization of the first-stage transfer gear blanks to improve NVH performance and reduce mass for EV applications. A multibody dynamic model of the eDU is constructed, incorporating asymmetric gear blank geometry, shaft elasticity, bearing stiffness, and housing flexibility, to characterize realistic operating conditions and simulate gear contact mechanics with high fidelity and computational efficiency. NVH excitation sources, including static transmission error and dynamic meshing force, are systematically evaluated for solid and slotted gear configurations. Based on a DOE optimization study, an 8-slot gear blank design is selected to balance mass reduction, stress, NVH, and manufacturing requirements. Micro-geometry optimization is conducted for the slotted
He, Song, Du, Isaac, Li, Bo, Bahk, Cheonjae, Grguras, Zachary, Baladhandapani, Dhanasekar, Patruni, Pavan Kumar
BEARING, BALL, AIRFRAME ANTIFRICTION, EXTRA LIGHT DUTY CORROSION-RESISTANT NITROGEN STEEL (CREN)AS27642/1A (Current)3/25/2026
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTIFRICTION, EXTRA LIGHT DUTYAS27646E (Current)3/19/2026
ACBG Rolling Element Bearing Committee
BEARING, ROLLER, NEEDLE, TRACK ROLLER, CROWN RADIUSED OD INTEGRAL STUD, TYPE VII ANTIFRICTION, INCHAS21447D (Current)3/19/2026
ACBG Rolling Element Bearing Committee
BEARING, ROLLER, NEEDLE, TRACK ROLLER, INTEGRAL HEAVY STUD, TYPE IX, ANTIFRICTION, INCHAS21441D (Current)3/18/2026
ACBG Rolling Element Bearing Committee
BEARING, ROLLER, NEEDLE-SINGLE ROW, HEAVY DUTY, SELF-ALIGNING, TYPE III, ANTIFRICTION, INCHAS24463E (Current)3/16/2026
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTI-FRICTION, EXTRA WIDE, DOUBLE ROW, INTERMEDIATE DUTY, CORROSION-RESISTANT NITROGEN STEEL (CREN)AS27647/1A (Current)3/16/2026
ACBG Rolling Element Bearing Committee
BEARING, BALL, AIRFRAME, ANTIFRICTION, INTERMEDIATE DUTYAS27641E (Current)3/16/2026
ACBG Rolling Element Bearing Committee
Plain Bearing High Speed Oscillation TestARP5448/2 (Current)3/6/2026
This test method outlines a standard procedure for performing cyclic reversing load testing on oscillating sliding bearings. The wear data from these tests is to be used for qualification requirements and to establish bearing design criteria.
ACBG Plain Bearing Committee
Efficiency Improvement of an Electric Vehicle e-Transaxle through Gear, Bearing, and Lubricant Optimization Strategies2026-26-00531/16/2026
Improving transaxle efficiency is vital for enhancing the overall performance and energy economy of electric vehicles. This study presents a systematic approach to minimizing power losses in a single-speed, two-stage reduction e-transaxle (standalone) by implementing a series of component-level design optimizations. The investigation begins with the replacement of conventional transmission oil with a next-generation low-viscosity transmission fluid. By adopting a lower-viscosity lubricant, the internal fluid resistance is reduced, leading to lower churning losses and improved efficiency across a wide range of operating conditions. Following this, attention is directed toward refining the gear macro-geometry to create a gear set with reduced power losses. This involves adjustments to parameters such as module, helix angle, pressure angle, and tooth count, along with the introduction of a positive profile shift. These modifications improve the contact pattern, lower sliding friction, and
Agrawal, Devesh, Bhardwaj, Abhishek, Bhandari, Kiran Kamlakar
Bearing Creep Prevention in EV Transmission2026-26-05981/16/2026
As the trend shifts from Internal Combustion Engine (ICE) vehicles to Electric Vehicles (EVs), the operating speeds of prime movers have significantly increased. Commercial EV manufacturers prefer high-speed, low-torque motors coupled with transmissions over low-speed, high-torque motors due to higher efficiency and power density. This combination of high-speed, low-torque motors coupled with transmission is essential for achieving the required gradeability and enhances operational efficiency. However, the increased operating speeds of these EV transmissions have inherently increased the risk of ‘bearing creep’ [8]. The “bearing creep” is the phenomenon where unintended relative motion occurs between bearing races and their mounting surfaces, leading to premature wear of mounting surfaces [3]. This issue can lead to a series of failure modes such as increased gear mesh misalignment, bearing damage, seal damage, etc. These problems result into elevated transmission vibrations eventually
Bagad, Sachin Sunil, Kanase, Ashish, Hiremath, Satalingayya, Nevarekar, Sandip
Power Loss Evaluation in 4WD Axle & Correlation with Testing Results2026-26-01071/16/2026
In tractors, efficiency is predominantly influenced by the transmission system, with transmission elements being the major contributors to power losses. Enhancing efficiency necessitates monitoring these power loss areas. Transmission power loss refers to the reduction in power from the engine to the final drive elements. Various parameters and factors affect these losses, and analyzing these conditions helps identify and improve the components that contribute most to driveline efficiency. This study correlates analytically calculated power loss with losses measured during testing under different load conditions. Additionally, critical parameters contributing to power loss in gears, bearings & in seals have been identified, and theoretical relationships have been established.
Jayapal, Jayaraj, Mahapatra, Soumya Ranjan, Sethi, Suvendu Kumar, Joshi, Shrikant, Bange, Prashant
Enhanced Methodologies for Predicting Automotive Wheel Bearing Life and Damage Using RLDA2026-26-04821/16/2026
The durability of wheel bearings is assessed in terms of raceway life and flange life. Raceway life focuses on the performance and damage tolerance of rolling elements, while flange life evaluates the structural integrity of wheel flanges under operational stresses. Traditionally, durability predictions relied on conventional design methods and analytic formulas for raceway spalling, as well as static load assumptions for flange fatigue analysis. Recently, integrating design of experiments (DOE) with traditional approaches has enhanced these methods, enabling systematic evaluation of design variables and loading conditions. This paper introduces a methodology for analyzing raceway life and damage in automotive wheel bearings using RLDA (Road Load Data Acquisition) data. The process involves acquiring raw deterministic load data, filtering it to preserve high-peaked signals, and transforming the filtered data into block cycles derived from load time histories. Each block cycle contains
Narendra, Vishwanath, Mane, Yogiraj, Paua, Ketan, Singh, Ram Krishnan, Vellandi, Vikraman
Simulation Based Optimization of the NVH Characteristics in Modern High Speed Engine During Development Phase2026-26-03261/16/2026
Engine noise mitigation is paramount in powertrain development for enhanced performance and occupant comfort. Identifying NVH problems at the prototype stage leads to costly and time-consuming redesigns and modifications, potentially delaying the product launch. NVH simulations facilitate identification of noise and vibration sources, informing design modifications prior to physical prototyping. Early detection and resolution of NVH problems through simulation can significantly shorten the overall development cycle and multiple physical prototypes and costly redesigns. During NVH simulations, predicting and optimizing valvetrain and timing drive noise necessitates transfer of bearing, valve spring, and contact forces to NVH simulation models. Traditional simulations, involved continuous force data export and NVH model evaluation for each design variant, pose efficiency challenges. In this paper, an approach for preliminary assessment of dB level reductions across design iterations is
Rai, Ankur, Deshpande, Ajay Mahadeo, Yadav, Rakesh
Research on Characterization Parameters of Main Bearing Wear Condition Based on Vibration Signals2026-01-50031/15/2026
This study aims to investigate the influence of torque, rotational speed, lubricating oil temperature, and main bearing clearance on the vibration signals of diesel engine block surfaces, thereby establishing a foundation for diagnosing abnormal main bearing wear conditions using engine block surface vibration signals. An experimental test bench was constructed for a six-cylinder diesel engine to collect vibration signals under varying rotational speeds, torques, lubricant temperatures, and main bearing clearances. Frequency domain analysis and wavelet packet decomposition were then performed. The frequency domain analysis results indicate that the vibration signal amplitudes associated with abnormal main bearing wear are primarily concentrated below 5 kHz. Specifically, the energy in frequency bands below 1 kHz and around 2.5 kHz tends to increase with higher rotational speed, torque, and main bearing clearance, while the overall frequency domain amplitudes decrease with rising
Dong, Yiming, Hu, Yuping, Ji, Shaobo, Pan, Chi, Yue, Yuanhang, Liao, Guoliang
Calculation of Bending Capacity of L-Shaped Concrete Filled Steel Tube Special Column2025-99-021512/23/2025
In this paper, a systematic and in-depth study is carried out on the key engineering problem of the accurate calculation of the flexural capacity of L-shaped concrete-filled steel tubular columns. Based on the basic framework of mechanics theory, the basic design principle of reinforced concrete members is integrated, and the nonlinear characteristics of steel and concrete materials in the process of stress are mainly considered, such as steel yield strengthening, concrete compression damage, etc., and the ultimate bending moment calculation model which is more suitable for the actual stress state is constructed. Through rigorous theoretical derivation and multi-parameter comparative analysis, the final formula for calculating the bearing capacity of special-shaped columns not only has clear mechanical concept support, but also systematically defines the scope of application of the calculation method. The verification results show that the established calculation method not only meets
Wang, Cuicui, Bai, Shouyan, Wei, Hongxian, Lv, Shuang, Xu, Yafeng
Design and Application of Large-Segment Cable Hanging Baskets for Long-Span High-Speed Railway Cable-Stayed Bridges2025-99-021912/23/2025
With the advancement of cable-stayed bridge construction technology, the application of long-span concrete girder cable-stayed bridge is gradually extensive, making the study of construction technology and equipment for concrete main girders increasingly important. The cable hanging basket, a crucial piece of equipment for cable-stayed bridge construction, maximizes the cable’s bearing capacity, improves construction efficiency, and ensures safety and stability during construction. However, due to the varying structural designs and construction environments, the cable hanging basket must be specifically tailored for different cases. The Hanjiang Bridge on the Xi’an-Shijiazhuang High-speed Railway is China’s first steel-truss-reinforced PC box-girder cable-stayed bridge, with a main span of 420 meters. If conventional diamond-shaped hanging baskets are used for suspended casting of small sections, the construction period will not meet the construction requirements of this bridge. To
Li, Jian
BEARING, ROLLER, NEEDLE, SINGLE ROW, HEAVY DUTY, TRACK ROLLER, SEALED, TYPE V ANTIFRICTION, INCHAS21438E (Current)12/11/2025
ACBG Rolling Element Bearing Committee
Response Analysis and Optimization of a Lightweight Seat Ring under Airborne Landing Impact2025-99-041112/10/2025
In order to meet the high lightweight and transmission accuracy requirements of a certain airborne system, the seat ring bearing adopts a lightweight material 4-point contact ball slewing bearing. However, the non-linear contact of a large number of balls during the working process of the seat ring makes simulation difficult, and ball damage often occurs in previous experiments. Based on the bearing capacity of the shaft, the influence of uneven load transmission of the ball on the response was considered. The response of the bearing under shooting and airdrop landing impact loads was calculated and analyzed using multi rigid body and finite element methods, respectively. The results indicate that under the impact load, the stress on the ball has exceeded the yield limit of the material, resulting in irreversible plastic deformation. The plastic deformation morphology is basically consistent with the damage morphology of the test ball, which verifies the accuracy of the simulation
Zhang, Taiping, Ning, Bianfang, Wang, Huating, Fan, He
BEARING, PLAIN, SELF-ALIGNING, PTFE LINED, WIDEAS21231B (Current)12/10/2025
ACBG Plain Bearing Committee
Experimental Analysis of Wheel Bearing Friction Losses Under Realistic Driving Cycles on a Component and Roller Test Bench2025-32-010011/3/2025
The ongoing electrification of vehicle powertrains brings attention to components with a minor contribution to overall friction losses in research and development. To optimize the overall energy efficiency, it is essential to analyze and reduce the losses in these components. Wheel bearings are of particular interest in this context, as their friction losses affect both the driving and recuperation phases. These losses are dependent on temperature, mechanical loads and the bearing mounting situation into the vehicle. The analysis of friction losses and their dependency on the factors mentioned above is usually conducted by measurements on component test benches to allow an isolated analysis. In contrast, the friction losses of the complete drive system are measured on powertrain or roller test benches. In this context, the factors affecting the losses in wheel bearings deviate from the measurements obtained on component test benches. The purpose of this paper is to analyses the effect
Hartmann, Lukas, Erxleben, Lars, Rebesberger, Ron, Henze, Roman, Sturm, Axel
Advanced 3D Simulations of a Four-Stroke High-Performance Engine Valvetrain for the Analysis of the Mechanical Stresses and Energy Losses2025-32-001011/3/2025
Enhancing the performance of naturally aspirated 4-stroke engines relies heavily on improving trapping efficiency, increasing maximum engine speed, and reducing friction losses. In this regard, the valvetrain plays a critical role. Achieving high volumetric efficiency at higher engine speeds necessitates very steep valve opening and closing ramps, making this aspect pivotal in the design process. At high engine speeds, significant dynamic phenomena arise, including valve float during the lift phase and valve bounce during the closing phase. These effects not only induce substantial modifications to the valve lift curve but also increase the mechanical stress on critical components such as the valve and the rocker arm, thereby elevating the risk of failure. Moreover, the timing system substantially contributes to overall engine losses due to frictional energy dissipation, which results from the numerous interactions between moving components. The present work aims to develop a numerical
Tarchiani, Marco, Pizzicori, Alessio, Raspanti, Sandro, Romani, Luca, Meli, Enrico, Ferrara, Giovanni, Trassi, Paolo
BEARING, PLAIN, SELF-ALIGNING, PTFE LINED, NARROWAS21233B (Current)10/23/2025
ACBG Plain Bearing Committee
BEARING, SLEEVE, PLAIN, SELF-LUBRICATING −65 TO +250 °FAS21240A (Current)10/23/2025
ACBG Plain Bearing Committee
BEARING, SLEEVE, FLANGED, SELF-LUBRICATING -65 TO +250 °FAS21241A (Current)10/23/2025
ACBG Plain Bearing Committee
FLANGE, SHEET METAL, WIDEAS4751/2A (Current)10/21/2025
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Minimum Standards for Valve, High Pressure Oxygen, Cylinder Shut Off, Manually OperatedAS1066C (Current)10/21/2025
This standard covers all types of manually operated high pressure oxygen, cylinder shut off valves for use in commercial aircraft. It is intended that the valve shall be attached to a pressure cylinder storing oxygen under a nominal pressure of 12.76 MPa (1850 psig) at 21 °C (70 °F). Upon opening the valve, oxygen will be permitted to discharge from the storage cylinder to the valve outlet and to other downstream components of the oxygen system. It shall also be possible to recharge the cylinder through the valve.
A-10 Aircraft Oxygen Equipment Committee
Bearings, Sleeve, Plain and Flanged, Self-Lubricating -65 to +250 °FAS8943A (Current)10/21/2025
This standard covers plain and flanged sleeve bearings which are self-lubricating by incorporating polytetrafluoroethylene (PTFE) in a liner in the bore for use in a temperature range of -65 to +250 °F (-54 to +121 °C).
ACBG Plain Bearing Committee
BEARING, PLAIN, SELF-ALIGNING, GROOVED OUTER RING PTFE LINED, WIDEAS21230B (Current)10/21/2025
ACBG Plain Bearing Committee
BEARING, PLAIN, SELF-ALIGNING, GROOVE OUTER RING, PTFE LINED, NARROWAS21232B (Current)10/21/2025
ACBG Plain Bearing Committee
Research on the Application of Ship Domain Model in Ship Collision Avoidance2025-99-006810/17/2025
In contemporary global commerce, swift advancements are observed within the maritime transportation sector. The frequency of seafaring voyages increases apace, from which it is discerned that navigational safety emerges as an indispensable concern. Paramount to safeguarding vessel operations and diminishing the susceptibility to maritime mishaps has become the integration of ship domain models. Through incorporation of AIS datasets alongside mathematical statistical evaluations melded with insights derived from ship captains, this discourse introduces a novel risk domain paradigm tailor-made for ships. The curated data amalgamated with maritime captaincy was stratified and overlayered, utilizing techniques such as the maximum density method juxtaposed with least squares calculation to ascertain the periphery defining the ship’s risk precinct. This newly conceived model interweaves aspects of ship maneuverability in concert with evasion protocols predicated on extant ship domain models
Xiong, Junting, Zhang, Yong, Chen, Xiaofeng, Meng, Fanjun, Zhang, Junpeng
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