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Damage matching criterion for development of accelerated duty cycle from road load data, and achieving right duty cycle to determine gear and bearing durability.

Romax Solutions-Amol Korde
  • Technical Paper
  • 2019-28-0121
To be published on 2019-10-11 by SAE International in United States
While designing the transmission, designer needs to have a duty cycle which is a set of load cases against which he wants to confirm the durability of the same. This is done through data acquisition by running a vehicle on various terrains and converting those data points to a concise set of load cases which we term as duty cycle. This is required because data acquired has millions of data points giving value of torque and RPM at every millisecond which cannot be directly used to assess the fatigue durability of gears and bearings. Converting these millions of road load data points into fewer number of load cases is always a challenge. For a transmission designer, it is being a major hurdle to determine as what is the scientific way of converting these millions of data points into a concise duty cycle. The road load data is taken for few hundred or few thousand kilometres covering enough types of terrains on which vehicle is expected to run. But the methods available with todays engineers does…

Design of Light Weight Footstep Using Continuous Glass Fiber Reinforced Plastic Brackets

Mahindra & Mahindra, Ltd.-Praveen Kumar, Vivek KV Shenoy, Ashish Kumar Sahu, Srivatsa Sriperumbudur, Anton Kumanan, K V Balaji
  • Technical Paper
  • 2019-28-0172
To be published on 2019-10-11 by SAE International in United States
Objective Utility or Off-road vehicles are characterized with their higher ground clearances. Higher ground clearance of vehicle requires the vehicle to have footsteps for easy entry and exit of passengers from the vehicle. A typical foot step construction consists of structural steel brackets with an Aluminium or plastic top panel. Conventional steel construction is heavier to meet weight bearing capacity and durability requirements. Our objective of this work is to explore lightweight materials which can meet these performance requirements with a lighter construction. We chose to study the continuous glass fiber reinforced plastic as an alternative to the metal construction. Methodology The continuous glass fibers in the PP matrix improves the material strength due to high strength to weight ratio. The strength of the matrix increases depending on the fiber length in the matrix. This technology uses twin screw extrusion and plunger type injection to retain the fiber length in the molded part which helps the part to bear higher loads depending upon the aspect ratio of fibers in the matrix. We have produced test…

Fault Detection in Single Stage Helical Planetary Gearbox using Artificial Neural Networks (ANN) with Histogram Features

BSACIST-Syed Shaul Hameed, Muralidharan Vaithiyanathan, Mahendran Kesavan
  • Technical Paper
  • 2019-28-0151
To be published on 2019-10-11 by SAE International in United States
Abstract Drive train failures are most common in wind turbines. Lots of effort has been made to improve the reliability of the gearbox but the truth is that these efforts do not provide a life time solution. Majority of failures are caused by bearing and gearbox. It also states that wind turbine gearbox failure causes the highest downtime as repair has to be done at Original Equipment Manufacturer [OEM]. This work aims to predict the failures in planetary gearbox using fault diagnosis technique and machine learning algorithms. In the proposed method the failing parts of planetary gearbox are monitored with the help of accelerometer sensor mounted on the planetary gearbox casing which will record the vibrations. A prototype has been fabricated as a miniature of single stage planetary gearbox. The vibrations of healthy gearbox, sun defect, planet defect and ring defect under loaded conditions are obtained. The signals show the performance characteristics of gearbox condition. These characteristics and their number of occurrences were plotted in a histogram graph. Predominant statistical features which represent the fault…

Lightweight Wheel Bearing with Dissimilar Materials for Vehicle

Hyundai Motor Group-Jaehee Lee
Iljin Global-Inha Lee, Seonho Lee, Heechan Shim, Jungyang Park
  • Technical Paper
  • 2019-01-2134
To be published on 2019-09-15 by SAE International in United States
Limited fossil fuel resources, air pollution, and global warming all drive strengthening of fuel economy and vehicle emission standards globally. Much R&D continues to be dedicated to improve fuel efficiency of automobiles and to reduce exhaust gasses. These include improvement of engine/driveline performance for higher efficiency, development of alternative energy, and minimization of air resistance through aerodynamic design optimization. OEM weight reduction-focused research has extended into chassis components (steering knuckle, brakes, control arms, etc.) in sequence from body-in-white(BIW). Wheel bearings, one of the core components of a driveline and part of a vehicle’s unsprung mass, are also being required to reduce weight. Conventionally, wheel bearings have achieved “lightweighting” primarily through design optimization methods. They have been highly optimized today using steel based materials. Opportunities for further mass optimization are increasingly limited and so the focus of this study is integration of lighter-materials into steel bearing components for weight savings. Both aluminum and CFRP were considered in the study for partial integration into the steel hub flange which interfaces directly with the wheel. The application of…

Study on Application Methods to Mitigate Galvanic Corrosion between Wheel Bearing and Aluminum Knuckle

Iljin Global-Sewoong Kim, Seonho Lee, Hyounsoo Park
  • Technical Paper
  • 2019-01-2136
To be published on 2019-09-15 by SAE International in United States
The substitution of aluminum for steel is an effective weight reduction solution where the application permits it; aluminum knuckles have been widely used for this reason. However, when an aluminum knuckle is assembled with the steel outer-ring of a wheel bearing without any means for galvanic corrosion prevention, the aluminum knuckle may severely corrode. Galvanic corrosion products can make it difficult to remove a wheel bearing from the aluminum knuckle during vehicle maintenance. Prevention of this problem is the focus of this paper. In this study, several concepts were examined to prevent or mitigate galvanic corrosion between a wheel bearing and its mating aluminum knuckle. One set of concepts involves using surface treated metal sleeves (using ferritic nitro-carburizing or a special coating). The sleeves were then inserted onto the outer-ring diameters of the wheel bearings prior to assembly into the steering knuckle. Another set of concepts that were investigated involves the application of thin coatings having high anti-corrosion properties. The coatings were applied directly to the bearing outer-ring knuckle piloting surfaces and bearing knuckle mounting…

Orbital Forming of Automotive Wheel Bearings

Orbitform-Jake Sponsler
  • Technical Paper
  • 2019-01-2133
To be published on 2019-09-15 by SAE International in United States
Orbital forming is considered an optimal assembly process for many designs of automotive wheel bearing assemblies. More specifically, this process involves forming the spindle over the inner race of the wheel bearing to maximize surface area contact on the inner ring for retention, and to maintain bearing preload. The unique forming properties and precise controls allow orbital forming to produce an ideal finished retention feature and form for these types of bearings. This paper discusses the specific benefits of orbital forming of automotive wheel bearings. Forming basics, the physics behind the benefits of orbital forming, as well as pre-form lip geometry and other part design considerations are presented. Advanced machine control methodologies and historical machine process improvements are also reviewed concluding with next steps in process control and in-machine quality assurance.

Development of a Low Friction High Performance Wheel Bearing Seal

ILJIN USA Corporation-Seungpyo Lee
Iljin Bearing GmbH-Reinhold Mahr
  • Technical Paper
  • 2019-01-2135
To be published on 2019-09-15 by SAE International in United States
The ever tightening of fuel economy and greenhouse gas emissions standards globally continues to challenge bearing companies toward lower torque, lower mass products. This paper focuses on improving fuel efficiency by considering the torque of automotive wheel bearing seals. This study establishes the level of drag torque reduction achieved through the structural design of the bearing seals. Wheel bearing seals are a critical component that must pass stringent torque, water exclusion, and other critical OEM and supplier performance specifications. They are designed as non-serviceable and must maintain full performance through the life of the vehicle. As a result of the application of specialized structural design, the drag torque, per the study, is reduced by more than 50% compared to existing bearing specifications. Electric vehicle companies are also seeking low friction wheel bearing solutions to further reduce CO2 (indirect or wheel-to-wheel) emissions. This research findings can assist the OEM’s in meeting the rigid emissions and fuel economy standards through drag reduction in the wheel bearings.

Bearing Life Optimization for Automotive Wheel Bearings

ILJIN USA Corporation-Seungpyo Lee
  • Technical Paper
  • 2019-01-2137
To be published on 2019-09-15 by SAE International in United States
Automotive wheel bearings have primary functions of translating the rotating motion of the wheels into linear vehicle motion while bearing the vehicle weight. Bearing life is affected by many parameters such as bearing geometry, vehicle and bearing technical specifications, driving conditions, lubrication conditions, material properties, and so on. In this paper, the optimization of bearing life was performed. Optimization formulation with no constraints was established to solve this problem. The large scale generalized reduced gradient, LSGRG, algorithm was applied to calculate the basic rating life and modified rating life proposed by ISO 281:1990 and ISO 281:2007, respectively. The optimization history for design variables and cost function were investigated. The results showed that the optimized basic rating life and modified rating life increased about 15% and 31% comparing with those of initial life, respectively.

Friction Reduction by Optimization of Local Oil Temperatures

University of Kassel-Oemer Oezdemir, Adrian Rienäcker
University of Stuttgart-Kevin Huttinger, Michael Bargende
  • Technical Paper
  • 2019-24-0177
To be published on 2019-09-09 by SAE International in United States
The reduction of engine-out emissions and increase of the total efficiency is a fundamental approach to reduce the fuel consumption and emissions of vehicles driven by combustion engines. Conventional passenger cars are operated mainly in lower partial loads most of their lifetime. Under these conditions, oil temperatures which are far below the maximum temperatures allowed, dominate inside the journal bearings. Therefore, the objective of this research project was to investigate possible potentials of friction reduction by optimization of the thermal management of the oil circuit of a combustion engine. Within the engine investigations, it was shown that especially the friction of the main and connecting rod bearings can be reduced with an increase of the oil supply temperature. For the investigations, the oil circuit of the test engine was modified to realize three separate oil circuits of main and connecting rod bearings, cylinder head and the piston jets with turbocharger, that were individually supplied with oil at different pressures and temperatures by an external system. Furthermore, on a journal bearing test rig it was shown…


E-25 General Standards for Aerospace and Propulsion Systems
  • Aerospace Standard
  • AS9276B
  • Current
Published 2019-08-15 by SAE International in United States
No Abstract Available.
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