Browse Topic: Universal joints

Items (404)

Steering Control Systems - Heavy Trucks

J2425_202111 (Current)

11/09/2021

This SAE Recommended Practice describes a laboratory test procedure and requirements for evaluating the characteristics of heavy-truck steering control systems under simulated driver impact conditions, as well as driver entry/egress conditions. The test procedure employs a torso-shaped body block that is impacted against the steering wheel.

Truck Crashworthiness Committee

Universal Joint End Yoke Connection (Earwork)

J2301_202101 (Current)

01/07/2021

This document specified the main dimensions and tolerances which affect interchangeability between end yoke earwork for the most common North American-used universal joints. Dimensions and tolerances of the mating universal joints are left to the discretion of the universal joint manufacturers. The term “earwork” refers to the configuration and geometry defining end yoke connections directly provided for universal joint cross attachment of drivelines. Earwork for certain styles of universal joint connections and flange connections have for a long time been proprietary to certain manufacturers. Over years of usage, proprietary rights have expired and the industry, as a whole, has used these earworks as standard. In an effort to tabulate some of the long-established practices, the following SAE Recommended Practice has been compiled. Manufacturers do from time to time, as the need arises, change tolerances or fits to better enhance component performance. This document has been prepared

Drivetrain Standards Committee

Universal Joint End Yoke Connection (Earwork)

J2301_202101-TEST-REC (Historical)01/07/2021

This document specified the main dimensions and tolerances which affect interchangeability between end yoke earwork for the most common North American-used universal joints. Dimensions and tolerances of the mating universal joints are left to the discretion of the universal joint manufacturers. The term “earwork” refers to the configuration and geometry defining end yoke connections directly provided for universal joint cross attachment of drivelines. Earwork for certain styles of universal joint connections and flange connections have for a long time been proprietary to certain manufacturers. Over years of usage, proprietary rights have expired and the industry, as a whole, has used these earworks as standard. In an effort to tabulate some of the long-established practices, the following SAE Recommended Practice has been compiled. Manufacturers do from time to time, as the need arises, change tolerances or fits to better enhance component performance. This document has been prepared

Drivetrain Standards Committee

An Interval Analysis and Optimization Method for Generated Axial Force of Automotive Drive Shaft Systems

2020-01-091804/14/2020

To study the generated axial force (GAF) of the drive shaft system more accurately and effectively, this paper introduces the interval uncertainty into the research focusing on the GAF. Firstly, an interval uncertainty model for calculating the GAF is proposed based on the Chebyshev polynomials and an analytical model of the GAF. The input torque, the articulation angle, the rotation angle of the drive shaft system, the pitch circle radius (PCR) of the tripod joint and the friction coefficient are regarded as interval variables. Secondly, the upper and lower bounds of the proposed GAF model under interval uncertainty parameters are calculated quickly with the vertex method. Then the interval uncertainty optimization of the GAF under uncertainty parameters is performed. The upper bound of the response interval of the GAF is taken as the optimization object. Finally, the proposed model is verified by experiments, while the interval uncertainty analysis and optimization of the GAF are

Feng, Huayuan, Rakheja, Subhash

Research on Fractal Friction Model between Balls and Arc Raceways inside a Ball Joint

2020-01-109304/14/2020

During the operation of the ball joint, its service life and transmission efficiency are affected by the internal friction. Taking the ball joint as the research object, based on fractal theory, the friction between the steel ball and the raceway inside the ball joint of an automotive drive shaft system is studied in this paper. During the analysis, the friction between the steel ball and the arc raceway is regarded as the friction between a sphere and an arc raceway surface. In order to describe the friction state more accurately, this paper proposes a correction coefficient to modify the distribution function of contact asperities in the plane, and obtains the distribution function of contact asperities between the sphere and the arc raceway surface. The correction coefficient is related to the load, the size parameters and the material parameters of the steel ball and the raceway. Then based on the modified distribution function, the fractal models of the friction coefficient, the

Feng, Huayuan, Li, XiHua

Bollinger Motors showcases second-gen Class-3 EV prototypes

19AUTP11_1611/01/2019

Bollinger Motors recently unveiled its second-generation Class-3 EV prototypes. The start-up, based in Ferndale, Michigan, revealed the latest beta of its B1 SUV and B2 truck prototypes, highlighting the amount of in-house engineering and design. As a Class 3 (GVWR 10,001 to 14,000 lb.) vehicle, the Bollinger Motors truck and SUV are in the same classification as a Ford F-350 or Ram/Chevy 3500 truck. “This is the only all-electric Class 3 truck with off-road capability,” founder and CEO Robert Bollinger said of the B2. “Our beta version vehicles look very much like the original alpha prototype vehicle that debuted in 2017, but almost every component on our B1 SUV and B2 truck prototypes is different,” said Karl Hacken, Bollinger Motors chief engineer. The four-door B1 and B2 are identical from the C-pillar forward, with the B2 truck's 139-in wheelbase stretching 20 inches longer than the SUV. Both aluminum-bodied prototypes feature a vehicle-length 16×14-in pass-through enabled by

GKN spreads premium propshaft tech to quiet pickup cabins

19AUTP10_1110/01/2019

It may seem a long way in engineering and NVH terms from premium European cars such as Audi's A5 and A7 to light duty trucks, but GKN Automotive has bridged that gap with its latest lightweight all-wheel drive (AWD) modular propshaft. Many pickups suffer a significant amount of unwanted NVH emanating from the front propshaft, with its two universal or CV joints and an interconnecting shaft positioned below and close to the passenger cabin. But now GKN Automotive has “re-characterized” its premium car driveline system to an entirely different vehicle category. “With a traditional truck front propshaft, the level of noise entering the cabin is perceived as a drone,” explained Michael Miller, GKN's propshaft product technology manager. “We've worked on applications of our new technology where the cabin NVH levels have been dramatically reduced. Positive results stem from the combination of joints used in our lightweight modular front propshaft.”

THE LIMITATIONS OF THE UNIVERSAL JOINT

08001406/25/2019

Kinematic Analysis and Simulation of the Double Roller Tripod Joint

2019-01-152606/05/2019

The kinematic model of the double roller tripod joint is established in order to analyze its kinematic characteristics and provide theoretical basis for its application and improvement. By means of spatial coordinate transformation, the translational and rotational motion equations of the rollers relative to the tracks and trunnions, the motion equation of the center of the tripod and the equations of the input/output angular displacement error and bending angle are derived. The motion simulation of the double roller tripod universal joint was carried out in ADAMS so as to verify the established kinematic model. The results show that the rollers of the double roller tripod joint only have periodic translational motions relative to the tracks while the rollers have both periodic translational and rotational motions relative to the trunnions. The tripod’s center does the circular motion on the tripod plane with the angular velocity 3 times of the input angular velocity. The input/output

Qiu, Yinyuan, Shangguan, Wen-Bin

New Half Shaft Bench Test Methodology for NVH Characterization

2019-01-155806/05/2019

The main purpose of this paper is to develop a reliable bench test to understand the vibratory behavior of the half shafts under applied torque comparable to an idle condition. In some cases, the half shaft path is a major factor influencing the idle vibration in the vehicle. At idle condition vehicle vibrations are caused by engine excitation and then they pass through different paths to the body structure. Half shaft manufacturers generally characterize shaft joints for their frictional behavior and typically there is no data for vibration characteristics of the half shaft under idle conditions. However, for predictive risk management, the vibratory behavior of the half shaft needs to be identified. This can be achieved from measured frequency response functions under preloaded test conditions. This bench test enables manufacturers to conduct comprehensive design of experiments on the impact of powertrain vibration input while transmitting through the half shaft into the vehicle

Siavoshani, Saeed, Vesikar, Prasad Balkrishna, Yuan, Wei, Abbas, Ahmad, Sturla, Francisco Antonio

Integrated Multi-Physics Simulation for Full-Vehicle Low Frequency NVH Optimization in HEVs

2019-01-145506/05/2019

The recent automotive industry trend towards electrification has created new challenges for NVH engineers. These challenges stem from new powertrain architectures and their complex interactions, the governing control strategies which aim to optimize energy management, and new unmasked sources of excitation. Additionally, vehicle manufacturers are attempting to reduce hardware testing in order to rapidly satisfy increasing production demand and to minimize its costs. Hence, to meet the above-mentioned challenges up front in the development process of Hybrid Electrical Vehicles (HEVs) while balancing competing design objectives of drivability, durability and NVH, a simulation-led design and optimization is required. NVH problems are often the result of mechanisms that originate through complex interactions between different physical domains (flow, electromagnetic, structural/mechanical, control logic, etc.) and the assembly of individual components into a complete system. Therefore

Gomez, Llorenc Foraste, Zeman, Jonathan, Liu, Jack

Experimental Investigation of Sliding on Tripod Constant Velocity Joints

2019-01-501703/13/2019

An automotive transverse transmission is articulated by mechanisms called constant velocity joints (CVJ). The joint allows the suspension to move freely. Its frictional behavior is not well known. However, the CVJ functional analysis makes it possible to identify important mechanical losses due to the friction of component elements. This article will focus on tripod side. An analysis of its behavior by designing and constructing a rig in order to qualify the sliding inside of the tulip between tracks and rollers has been initiated. Thanks to three-dimensional (3D) printing and sport camera a new approach was established.

Ripard, Valentin, Ville, Fabrice, Cavoret, Jérôme, Ruzek, Michal, Charles, Pierre, Diaby, Moussa

Optimizing Steering Column Layout and UJ Phase Angle to Enhance Vehicle Dynamics Performance

2019-01-501002/05/2019

Vehicle dynamics is one of the most important vehicle attributes. It is classified into three domains, the longitudinal, vertical, and lateral dynamics. This paper focuses on optimizing the lateral vehicle dynamics which is driven by the straight ahead controllability and cornering controllability of the vehicle. One of the important parameters that dictates these sub-attributes is the steering ratio. Therefore, designing the right steering ratio is critical to meet the vehicle “specific” targets. Significant amount of work has been done by many researchers on variable steering ratio by implementing variable gear ratio (VGR) rack, active steering, and steer-by-wire systems. This paper discusses the methodology and considerations to optimize the steering ratio for a constant gear ratio rack by optimizing the steering column layout, viz., orientation and the phase angle in universal joints. A detailed analysis of steering system layout is done to optimize the steering ratio to enhance

Puvvula, Praneeth, Ravuri, Susheel, Dubal, Ajit, Salunkhe, Swapnil

Design and Development of a Retrofit Solution for Converting a Conventional LCV into Parallel Hybrid Electric Vehicle

2019-26-011701/09/2019

In today’s scenario, the emission norms are getting stringent day by day due to an increased level of pollution. The world is shifting towards low carbon footprint which made it necessary to adopt efficient technologies with fewer emissions. The hybridization of vehicles has resulted in improved efficiency with lower emissions which can fulfil the near future emission norms. Retrofitting of hybrid components into a conventional IC engine vehicle is so far the best way to achieve better performance both economically and technologically. This research is primarily focused on the design and development of a novel retrofit solution of P3x architecture for the light commercial vehicle. This retrofit solution is different from other hybrid solutions in terms of powertrain. It contains an innovative add-on powertrain along with the existing powertrain. This additional powertrain consists of a pair of helical gears followed by a chain and sprocket as a coupler for traction motor. The newly

Kumar, Ravindra, Kaundinya, Ashwin Subramanian, Shah, Ravindra, Ghugal, Swapnil, Kale, Jyoti Ganesh, Thorat, Vivek, Barik, Saroj, Shinde, Sanket

Torsional Fluctuations Consideration while Design of Synchro Rings

2018-01-182309/10/2018

In today’s manual transmissions of car, gearshift system requires high performance with particular emphasis on low effort, minimal travel and positive feel. To meet these targets, a high capacity multi cone synchronizers along with higher co-efficient of friction material used for lower gears. The design of synchronizer with these specifications is influenced by torsional fluctuations from engine. Excessive torsional vibrations leads to wobbling of synchro rings within the peripheral clearances with surrounding parts. Wobbling leads to abrasion wear of frictional area of synchro ring causing grating or crashing noise of gears during shifting. This paper presents the optimization of the multiple cone synchronizer design exposed to excessive torsional vibrations and validation of the same on test bench during development stage instead vehicle level validation.

Tawhare, Nitin, Aswale, Dhananjay, Ponkshe, Makarand

GKN turns the CV joint inside-out

18AUTP09_0909/01/2018

GKN Driveline is developing an innovative driveshaft concept that literally turns inside out the traditional configuration of the constant-velocity joint (CVJ), bringing potential benefits to both high-performance rear-wheel-drive vehicles-and future electric vehicles (EVs). In a conventional design, CVJ housings face outward from the sideshaft, while the sealing systems on each end face inward; GKN has been testing a layout in which the CVJ reverses the positions of these components within a sideshaft system, integrating the CVJ housings within the sideshaft itself.

Investigation on Dry-clutch Transmissibility Characteristic for Vehicle Launch Shudder

2018-01-122504/03/2018

Vehicle launch shudder is the terminology used in automotive industry to describe severe longitudinal oscillation during clutch engagement under start-up condition. This paper presents and implements detailed investigation for dry-clutch engagement and disengagement process, in order to deeply analyze vehicle launch shudder phenomenon which seriously deteriorates ride comfort. Firstly, diaphragm spring and cushion spring and link strip, which are three elastic components related to dry-clutch engagement and disengagement process in axial direction, are studied for their elastic properties, respectively, to obtain relationship between load and deflection. The elastic properties of these three elastic components are taken into considerations to establish nonlinear relationship between release bearing travel and clutch clamp force. Then, based on multi-body system dynamics theory, the lumped mass method is used to model the powertrain of front-engine and front-wheel-drive vehicle equipped

Yuan, Renfei, Wu, Guangqiang

Development of Axial Force Testing System for Wheel Bearing

2017-01-252209/17/2017

The actual installed conditions of 1st, 2nd and 3rd generation of wheel bearing were introduced. The theoretical factors of the axial fastening force for the axle (or CVJ bolts) and nuts were analyzed and the requirements for building up a precise axial force test system were given out. Four testing plans were discussed for the requirements. Based on the cases, the axial force test system was built up, and the axial force test was successfully carried out for the front wheel bearing of a car.

Wen, Chao, Luo, Tong, Huang, Dejie, Liu, Yu, Zhang, Lu

The Effect of Outer Ring Distortion on Wheel Bearing Friction Torque

2017-01-252109/17/2017

Wheel bearing friction torque (“drag”) directly contributes to vehicle fuel economy and CO2 emissions. At the same time, one of the most important factors for long-term durability of wheel bearings is effective seal performance. Since these two factors are often in conflict, it is important to balance the desire for low friction with the need for optimal sealing. One factor that affects wheel bearing sealing performance is the distortion of the outer ring that occurs when the bearing is mounted to the steering knuckle with fasteners. Minimizing this distortion is not just important for sealing, however. This paper explores the relationship between the outer ring distortion and the resulting friction torque. A design of experiments (DOE) approach was used in order to study the effects of the fastening bolt torque, constant velocity joint (CVJ) fastening torque, and outer ring distortion on component-level drag. The correlation shows the importance of maintaining raceway roundness in

Scherer, Stacey

Driveline Boom Noise Reduction through Simplified FEM Approach

2017-26-021501/10/2017

In today's competitive automobile marketplace with reduced vehicle development time and fewer prototypes/tests, CAE is playing very crucial role in vehicle development. Automobile environment demands ever improving levels of vehicle refinement. Performance and refinement are the key factors which can influence the market acceptance of vehicle. Driveline is one of the key systems whose refinement plays critical role in improved customer satisfaction. Because of the virtue of the driveline functionality, driveline induced noise and vibration are the most common issues in the AWD vehicle development programs. Refinement of the drive line needs complicated nonlinear full vehicle CAE MBD models for the evaluation of driveline induced noise and vibration responses at different operating conditions [1]. In this paper a simplified approach is adapted for solving the Noise & Vibration issue which has been identified at the prototype testing level of an AWD vehicle development. Linear finite

Krishna, Kodali Ajay, Patil, Sanjeev

CVJ and Knuckle Design Optimization to Protect Inboard Wheel Bearing Seals from Splash

2016-01-195609/18/2016

For higher mileage vehicles, noise from contaminant ingress is one of the largest durability issues for wheel bearings. The mileage that wheel bearing sealing issues increase can vary due to multiple factors, such as the level of corrosion for the vehicle and the mating components around the wheel bearing. In general, sealing issues increase after 20,000 to 30,000 km. Protecting the seals from splash is a key step in extending bearing life. Benchmarking has shown a variety of different brake corner designs to protect the bearing from splash. This report examines the effect of factors from different designs, such as the radial gap between constant velocity joint (CVJ) slinger and the knuckle, knuckle labyrinth height and varying slinger designs to minimize the amount of splash to the bearing inboard seal. This report reviews some of the bearing seal failure modes caused by splash. This study also discusses the test methodology to confirm the robustness of the various designs and

Sutherlin, Robert G., Reed, Douglas

Virtual Drivetrain Simulation Using Adams View and Correlation with Test

2016-01-136104/05/2016

Reducing the vibrations in the drivetrain is one of the prime necessities in today’s automobiles from NVH and strength perspectives. The virtual drivetrain simulation methodology to predict the driveline induced excitations transmitted to vehicle is developed for three cylinder engine using Adams View. The obtained mount forces from Adams dynamic simulation is correlated with the measured test data at vehicle level and the good correlation is observed. Paper discusses on the methodology of virtual drivetrain using Adams view and the correlation of measured dynamic mount forces with simulation results. This correlation gives the confidence that the developed simulation methodology can be used to get the mount forces of different orders from drivetrain.

Londhe, Abhijit, Yadav, Vivek, Kannaiyan, SenthilKumar, Karthikeyan, Krishnan, Reddy, Ganeshan

Impact of Nanofluids on Heat Transfer Performance of a Motorcycle Radiator

2016-01-018804/05/2016

In the present work, the effect of various nanofluids on convective heat transfer performance in an automotive radiator was analyzed based on measured nanofluid properties. Al2O3, TiC, SiC, MWNT (multi-walled nanotube) and SiO2 nanoparticles ranging between 1 and 100 nm in size were dispersed in distilled water to form nanofluids. An ultrasonic generator was used to provide uniform particle dispersion in the fluid and keep the mixture stable for a long period of time. The impact of various particle types and their volume concentration on fluid properties such as density, thermal conductivity and viscosity were experimentally analyzed. It is observed that the nanofluid properties increased with the increase in particle volume concentration. TiO2 nanofluids were observed to show the highest increase in density (2.6% higher than the base fluid at a 1% vol. concentration) and also the largest enhancement in thermal conductivity (7.5% augmentation at 1% concentration). SiO2 nanofluids

Mathivanan, Elankathiravan, Liu, Liping

Offset Driveline for Tractors

2016-28-012802/01/2016

Tractors with 4WD drive perform better in slick, off road or muddy conditions (especially in Agricultural and constructional Field applications) where torque is required at all the wheels. The purpose of four wheel drive or all-wheel drive is to transmit power to all the wheels. In case of 2WD the power from engine is transferred to the rear wheels of a tractor through transmission. But in case of 4 WD tractors and construction equipment, power from engine is transferred to the front wheels through drop box and the driveline (propeller shaft). This Paper describes the need of an offset driveline where there is an offset between the Drop box output shaft center and the front axle input shaft center. This offset is the result of zero keel angle of the tractor. In order to maintain zero keel angle and transfer power to front wheels, an offset driveline with three shafts has been design &developed. Additionally a concept for an offset driveline which has been experimentally proven for

Chaudhari, Navneet, Sethi, Suvendu Kumar, Srinivasa, Rao

Companion Flanges, Type A (External Pilot) and Type S (Internal Pilot)

J1946_201601 (Current)01/26/2016

This SAE Standard specifies the nominal dimensions and tolerances which affect the interchangeability between companion flanges and mating parts. The flanges covered by this document are designated type A and type S. The type A flanges are equivalent to type A ISO 7646. The type S flanges are equivalent to the type S ISO 7647. Type A is an external (male) pilot construction and type S is an internal (female) pilot construction. These flanges are not interchangeable. Dimensions not specified are left to the discretion of the component manufacturer.

Drivetrain Standards Committee

Front-Wheel-Drive Constant Velocity Joint Boot Seals

J2028_201601 (Current)01/15/2016

This SAE Recommended Practice outlines the qualification testing and performance related criteria of elastomeric boot seals used in constant velocity joint applications. These applications are referred to as front- wheel-drive halfshafts or axles, but can also be utilized in rear-wheel-drive halfshaft applications. For additional information regarding CV joint systems and their applications refer to SAE AE-7 “Universal Joint and Driveshaft Design Manual.”

Drivetrain Standards Committee

Universal Joint End Yoke Connection (Earwork)

J2301_201601 (Historical)01/15/2016

This document specifies the main dimensions and tolerances, which affect interchangeability between end yoke earwork for the most common North American used universal joints. Dimensions and tolerances of the mating universal joints are left to the discretion of the universal joint manufacturers. The term “Earwork” refers to the configuration and geometry defining end yoke connections directly provided for universal joint cross attachment of drivelines. Earwork for certain styles of universal joint connections and flange connections have for a long time been proprietary to certain manufacturers. Over years of usage, proprietary rights have expired and the industry, as a whole, has used these earworks as standard. In an effort to tabulate some of the long established practices, the following SAE Recommended Practice has been compiled. Manufacturers do from time to time, as the need arises, change tolerances or fits to better enhance component performance. This document has been prepared

Drivetrain Standards Committee

Retrofitting of an Electronic System to Control and Data Acquisition in an Automotive Dynamometer for Didactic Use

2015-36-028109/22/2015

Integrated controls for commercial dynamometers do not have appropriate characteristics to perform research and teaching tasks. These are developed to perform quick tests and its logic is prepared to obtaining the information in accordance with the technical standards. This way, the use for research is hindered because it does not have an interface that allows a refinement to the desired data ranges, t data sampling and the type of load that is applied. Its use for teaching is limited because these "standard" controls does not allow to analyze or to determine engines characteristics that are not covered through tests specified by the standards, so the use of this tool as an important part in professional training formed by the institution. The development of a system control to the electromagnetic brake and capture of torque and rotation data will allow better use of dynamometers for research and teaching, providing to the students the knowledge of the control system itself and data

Vandresen, Marcelo, Silveira, James, Pereira, Milton, Chaplin, Richard, Fernandes, Gustavo

Torsional Vibration Analysis of Powertrain and Driveline Using Finite Element Method

2015-01-228706/15/2015

Among the lower frequency vehicle NVH problems, booming noise is one of the most concerned issues. One of the most common booming noise sources is the torsional vibration of the powertrain and driveline for rear-wheel drive and four-wheel drive vehicles. The solutions for this problem are either to use a torsional dynamic absorber or to use a lower stiffness clutch. Both solutions require the modal frequency of the torsional vibration mode of the powertrain and driveline. At early design stages, vehicle prototype is not available for measuring this frequency. Analytical method is usually used to calculate this frequency. Currently, mostly used method is the so-called 1D method in which the whole powertrain and driveline are represented by one-dimensionally connected disks (lumped inertia) and shaft (lumped stiffness). However, those lumped parameters are not always available at early design stage. In this paper, a method using finite element models is presented. In this method, all

Deng, Yaqiong, Zhao, Yanjing, Zeng, Xiandi

Experimental Investigation of Effect of Driveline Torsional Fluctuations on Overall NVH Performance of the Vehicle

2015-01-219206/15/2015

Meeting various customer(s) requirements with the given automotive product portfolio within the stipulated time period is a challenge. Design of product configuration matrix is an intelligent task and it requires information about vehicle performance for different configurations which helps in deciding the level of new development. Most often the situation arises, particularly in the field of NVH, to strike the right balance between engine power and structural parameters of the body. The sensitivity of engine power on the overall NVH behavior is the key information necessary to take major business decisions. In this paper, the effect of change in torsional fluctuation of the engine on the NVH behavior of the rear wheel drive vehicle is experimentally studied. The torsional fluctuation of the driveline is given as an input with the help of an electric motor to the existing test vehicle at its differential end and the current NVH levels are measured. A test rig is built to change the

Rao, Manchi Venkateswara, Frank, Jos, Raghavendran, Prasath

Brake Noise Prediction Using Altair Multi-Body Simulation

2015-36-000205/13/2015

The level of noise transmitted to the passengers of a vehicle can drastically impact a passenger's comfort. Brake noise will give the customer an impression of poor product quality and can thus damage the quality image of the company. Within the automotive industry, the study of mode coupling instability by the use of FEM and modal complex analysis is widespread to reduce this phenomenon. In this paper an alternative method is presented, where potential brake noise issues are predicted by the use of a time transient integration using multi-body system analysis. The simulation model contains a nonlinear contact description, bushing, flexible bodies and the axis kinematics of the vehicle. Transient results are transformed by Fourier for a frequency domain study. The parameters that can be varied for the prediction analysis are brake pressure, vehicle speed, friction laws, system damping and bushing properties. The advantages of the multi-body system analysis approach are in the direct

Sundaresh, Keshav, Leila, Felipe Moretti

J501_201406 (Current)06/05/2014

Materials, Processes and Parts Council

Influence of Active Subsystems on Electric Vehicle Behavior and Energy Characteristics

2014-01-087604/01/2014

Nowadays there is a tendency to implement various active vehicle subsystems in a modern vehicle to improve its stability of motion, handling, comfort and other operation characteristics. Since each vehicle subsystem has own limits to generate supporting demand, their potential impact on vehicle dynamics should be analyzed for steady-state and transient vehicle behavior. Moreover, the additional research issue is the assessment of total energy consumption and energy losses, because a stand-alone operation of each vehicle subsystem will provide different impact on vehicle dynamics and they have own energy demands. The vehicle configuration includes (i) friction brake system, (ii) individual-wheel drive electric motors, (iii) wheel steer actuators, (iv) camber angle actuators, (v) dynamic tire pressure system and (vi) actuators generating additional normal forces through external spring, damping and stabilizer forces. A passenger car is investigated using commercial software. The actuator

Shyrokau, Barys, Savitski, Dzmitry, Wang, Danwei

Finite Element Method Limitation for Natural Frequencies Determination of Automotive Components

2013-36-030910/07/2013

Engine downsizing is the use of a smaller engine in a vehicle that provides the power of a larger one. It is the result of car manufacturers attempting to provide more efficient vehicles by adding modern technologies, for instance, turbochargers, direct injection and variable camshaft. The smaller engine is also lighter and provides torque and power with similar performance to a much larger engine. However, the downsizing technique may lead to undesirable vibration effects on the driveline, such as structural damaging, vibration fatigue failure and extra noise. All these issues are related to natural frequencies investigation and they are often determined through the finite element method together with experimental tests during the product development phase. This work presents the finite element method limitation for natural frequencies determination of automotive components and a possible solution for the issue.

Souza, Thales Sardinha Garcia, Novo, Felipe Moura Fontes, de Souza, Mauro Moraes, Savoy, Juliano

Conceptualization and Implementation of an AWD Parallel Hybrid Powertrain Concept

2013-01-144804/08/2013

The Deep Orange [1] initiative is an integral part of the automotive graduate program at Clemson University International Center for Automotive Research. The initiative was developed to provide the graduate students with hands-on experience of the knowledge attained in the various engineering disciplines and related disciplines (such as marketing and human factors psychology). For the 3rd edition of Deep Orange, the goal was to develop a blank sheet hybrid mainstream sports car concept targeted towards the Generation Y (Gen Y) market segment. The objective of this paper is to elaborate on the overall development process and the technology that was created and integrated. A unique all-wheel-drive (AWD) parallel hybrid concept was derived based on extensive analyses of the Gen Y market. The data revealed that Gen Y, as an environmentally conscious generation, is willing to invest in sustainable powertrain technologies and also has a significant interest in all-wheel-drive. Based on these

Venhovens, Paul, Pisu, Pierluigi, Prucka, Robert, Makkar, Bhavuk, Frommann, Patrik, Sonavane, Tejas, D'Amico, Chris

Development of an Analytical Modeling Method and Testing Procedures to Aid in the Design of Cardan Joints for Front Steerable Beam Axles

2013-01-081904/08/2013

The Cardan joint of a steerable beam front axle is a complicated mechanical component. It is subjected to drive torque, speed fluctuations, and joint articulation due to powertrain inputs, steering, and suspension kinematics. This combination of high torque and speed fluctuations of the Cardan joint, due to high input drive torque and/or high steer angle maneuvers, can result in premature joint wear. Initially, some observations of premature wear were not well understood based on the existing laboratory and road test data. The present work summarizes a coordinated program of computer modeling, vehicle Rough Road data acquisition, and physical testing used to predict the joint dynamics and to develop advanced testing procedures. Results indicate analytical modeling can predict forces resulting from Cardan joint dynamics for high torque/high turn angle maneuvers, as represented by time history traces recorded in rough road data acquisition. This new approach can then be used to size the

Thom, Gerald, Sheets, Alan, Brendel, Frederick F., Long, Kah Wah

The Effect of Multi-Universal Coupling Phase on Torsional Vibration of Drive Shaft and Vibration of Vehicle

2013-01-149004/08/2013

Torsional vibration of drive shaft has great influence on the vibration of vehicle. Reasonable phase arrangement of multi-universal coupling can attenuate vibration. In this paper, theoretical model of drive shaft with planar multi-cross universal coupling was established; the optimization scheme of the phase arrangement of multi-cross universal coupling was presented. The results of test validation and simulation show that the optimization scheme is effective and reasonable. The results of test validation and simulation show that the optimization scheme was effective and reasonable and the optimized scheme could solve the abnormal vibration on floor. Arranging phases of universal joints reasonably is very significative for attenuate the torsional vibration of drive shaft and the floor vibration.

Wu, Guangming, Shi, Wenku, Chen, Zhiyong

Experimental Study of a Pre-Chamber Jet Igniter in a Turbocharged Rotax 914 Aircraft Engine

2013-01-162904/08/2013

An experimental study is performed to investigate the possibility of relaxing the octane requirement of a Rotax 914 engine equipped with a pre-chamber jet ignition system. A pre-chamber jet igniter with no auxiliary fuel addition is designed to replace the spark plug in cylinder two of the test engine and is evaluated across engine speeds ranging from 2500 to 5500 RPM. Experiments are performed across both normally aspirated and boosted configurations using regular 87 AKI gasoline fuel. Normally aspirated results at 98 kPa manifold absolute pressure show a 7-10° burn rate improvement with the jet ignition combustion system. Tests to determine the maximum load at optimal combustion phasing (no spark retard) are then conducted by increasing boost pressure up to maximum knock limits. Boosted jet ignition results demonstrate that 17 bar IMEPn can be achieved using 87 AKI gasoline fuel, which is the highest documented load achieved with this combustion system at stoichiometric conditions

Anderson, Eric K., Attard, William P., Brown, Adam, Litke, Paul, Grinstead, Keith, Hoke, John

Development of Active Vibration Control System for Driveshafts

2013-01-002803/25/2013

Driveshafts are one of the most important components in power-train system in vehicle as it transfer torque generated from engine to wheels in high speeds. As a driveshaft is in rotating condition vibration problems can be observed by resonance or external force. The generated vibration problems in vehicles cause discomfort to drivers whenever they are driving. To solve these problems, there have been many attempts to control such generated vibration in vehicle. In this study, vibration control system for driveshaft has been proposed to reduce the generated vibration. The smart damper for the system is designed considering to be implemented in driveshaft with quick response and a compact size. The damper is consists of electromagnets so it can response relatively quickly compared to other damping system. When a driveshaft reaches to its natural frequency, vibration control system with the damper is activated to minimize the vibration as it shifts its natural frequency region. The test

Bak, Jeong-Hyeon, Lee, Kwang-Hee, Park, Jeong-Lyul, Lee, Chul-Hee, Lee, Eun-Sang, Kim, Nam-Kyung

An Innovative Lightweight Solution for Connect a Prop Shaft with a Differential

2012-36-028410/02/2012

Prop shafts and differentials have been improved continuously. They are getting even more efficient and more lightweight. But the interface between these two parts looks still the same since more than 50 years what gives us a great chance for improvement. Rear or front axle differentials are currently fitted with a flange. This flange is necessary to connect the prop shaft frictionally with the differential during the final assembly. The substitution of universal joints by constant velocity joints gives the possibility of replacing a flange connection by a compact, lighter screwed connection. This paper will present a new single piece screwed solution which fits perfectly on the demands of modern all- / rear - wheel driven cars.

Karl, Christoph, Haas, Roman

Lateral Vibration Prediction of Drivelines Having a Flexible Coupling

2011-01-223809/13/2011

This work provides a theoretical analysis of the natural and forced lateral vibration in a driveline having a flexible coupling and universal joints. The analysis is specific to the front driveline common in many off-highway vehicles which usually consists of a flexible coupling at the engine flywheel, the driveshaft, and one or two universal joints. A torsionally flexible coupling is often needed in a front driveline to suppress torsional vibration. The problem is that most torsionally flexible couplings are also inherently flexible in their radial and cocking directions. These additional directions of flexibility, compounded by the presence of universal joints, can result in unexpectedly low lateral natural frequencies of the driveline. With a few axial dimensions, mass properties of the driveline, and stiffness properties of the flexible coupling, this work provides simple, closed-form calculations for the lowest lateral natural frequencies. This work also investigates the lateral

Sweeney, Shannon K.

Correlation between Virtual and Physical Test for Offset Deformable Barrier Crash for SUV

2011-26-009101/19/2011

In the present age automotive manufacturers are putting their effort to reduce product cycle time and product cost. This has been possible with the help of Computer Aided Engineering (CAE). CAE is playing vital role in design and develop of new products as well as up gradation of existing one to meet new safety regulations and customer requirements. It has become increasingly accepted that use of well-developed, CAE models present the best approach for upfront prediction of vehicle behaviour. The ability to simply predict trends is no longer acceptable. Meaningful results can be derived, and projections made, from the CAE model, only if the CAE results are correlated against physical tests. Correlation between Simulation and Physical test is key, to build confidence on product development with virtual validation. This paper discusses the correlation between the CAE and Physical Test for offset deformable barrier crash for 4 Wheel Drive (4WD) Sports Utility Vehicle (SUV) vehicle. It

Jain, Ritesh Kumar, Sharma, Manish

Power Train Model Refinement Linked with Parameter Updating Through Nonlinear Optimization

2010-01-142106/09/2010

In the virtual development process validated simulation models are requested to accurately predict power train vibration and comfort phenomena. Conclusions from refined parameter studies enable to avoid costly tests on rigs and on the road. Thereby, an appropriate modeling approach for specific phenomena has to be chosen to ensure high quality results. But then, parameters for characterizing the dynamic properties of components are often insufficient and have to be roughly estimated in this development stage. This results in a imprecise prediction of power train resonances and in a less conclusive understanding of the considered phenomena. Conclusions for improvements remain uncertain. This paper deals with the two different aspects of model refinement and parameter updating. First an existing power train model (predecessor power train) is analyzed whether the underlying modeling approach can reproduce the physical behavior of the power train dynamics adequately. Thereby especially

Girstmair, Josef, Priebsch, Hans H., Reich, Franz, Zehetner, Josef

Steerable Hopping Six-Legged Robot

TBMG-808006/01/2010

The figure depicts selected aspects of a six-legged robot that moves by hopping and that can be steered in the sense that it can be launched into a hop in a controllable direction. This is a prototype of hopping robots being developed for use in scientific exploration of rough terrain on remote planets that have surface gravitation less than that of Earth. Hopping robots could also be used on Earth, albeit at diminished hopping distances associated with the greater Earth gravitation.

Steerable Hopping Six-Legged Robot

TBMG-TB-00808006/01/2010

Motions of spring legs are coordinated in both launch and landing. The figure depicts selected aspects of a six-legged robot that moves by hopping and that can be steered in the sense that it can be launched into a hop in a controllable direction. This is a prototype of hopping robots being developed for use in scientific exploration of rough terrain on remote planets that have surface gravitation less than that of Earth. Hopping robots could also be used on Earth, albeit at diminished hopping distances associated with the greater Earth gravitation.

More About Reconfigurable Exploratory Robotic Vehicles

TBMG-552508/01/2009

Modular exploratory robotic vehicles that will be able to reconfigure themselves in the field are undergoing development. These vehicles at the initial concept stage were described in “Reconfigurable Exploratory Robotic Vehicles” (NPO-20944), NASA Tech Briefs, Vol. 25, No. 7 (July 2001), page 56. Proposed for use in exploration of the surfaces of Mars and other remote planets, these vehicles and others of similar design could also be useful for exploring hostile terrain on Earth.

Design and Analysis of a Gear Rattle Test Rig

2009-01-211305/19/2009

Gear rattle in manual transmission systems is a complex phenomenon and problematic to transmission and vehicle manufacturers. In the last three decades some inroads have been made in applying analytical and numerical analysis to understand rattle, however solutions and design methodologies for low rattle or no rattle are elusive. Problems with rattling transmissions continue to plague the industry. Controlled experiments for transmission rattle are required for research, to aid in the development of design tools and for validation of these tools. This paper presents a test rig which utilises a Hooke's joint to induce the torsional oscillations that lead to rattle. The design process relies on torsional lumped mass modeling and linear and transient nonlinear analyses and this paper details how the correct specification of the required driving motor isolation system is achieved. The rig complements the ongoing development of advanced rattle simulation tools and design methodologies and

Crowther, A. R., Rozyn, M. K.

Development of a Multi-Body Systems Approach for Analysis of Launch Shudder in Rear Wheel Driven Vehicles

2009-01-207305/19/2009

Driveline shudder is a low-frequency (10 Hz - 30 Hz) vibration issue of vehicles that can occur under various test conditions. Specifically, launch shudder is an issue that can be prevalent under vehicle take-off conditions. Factors that typically contribute to launch shudder include stick-slip excitation of friction materials (clutches) and driveline excitations, in particular, on rear wheel drive (RWD) vehicles. Shudder caused by the driveline excitation is generally related to the universal joints (Cardan joints) in the driveline system. In this case, the u-joint forces and kinematics induce a 2nd order excitation when operated under a driveline angle. This document focuses on launch shudder phenomena resulting from driveline system excitation on a RWD vehicle. An initial treatment of the physics governing launch shudder and typical factors influencing the shudder levels in vehicle are provided. Following this, the development of a multi-body systems (MBS) based approach is

Wellmann, Thomas, Govindswamy, Kiran

Solution for the Torque Steer Problem of a Front-wheel Drive Car with a High-torque Engine in Vehicle Development Stages

2007-01-365608/05/2007

This paper describes a torque steer reduction process for a front-wheel drive car with a high torque engine at the initial stage of vehicle development. Literature reviews for the reduction process and vehicle integration tradeoffs among chassis components, driveline components, and loading condition are included. Drive shaft angle and its stiffness, differential gear stiffness, and power train mount, and vehicle weight distribution are mainly considered. In addition, wheel alignment data such as kingpin offset, kingpin inclination, camber angle, ride height, and dynamic tire radius are also discussed to solve the torque steer problem. This paper introduces an example solution to improve the torque steer during vehicle development stage. In that case, the vehicle parameters should be considered the factors to achieve many requirements. In spite of that restriction of alteration, the result of improvement became better than that of its competitor. ADAMS/Car model simulations are carried

Woo, Seunghoon, Park, Sungmun, Oh, Youngho

Selection and Unintended Consequences of Torsionally Flexible Couplings in Drivelines of Off-Highway Vehicles and Stationary Industrial Units

2007-01-242505/15/2007

The procedure for selecting a flexible coupling to suppress driveline torsional vibration from the engine of an off-highway vehicle or stationary industrial unit with a remotely mounted driven unit is widely studied and documented. However, the successful selection of a torsionally flexible coupling in an off-highway vehicle or stationary industrial unit to suppress engine vibration can create new vibration and performance problems in the driveline and driven unit. This paper presents the unintended consequences of utilizing a torsionally flexible coupling, provides descriptive solutions to the unintended consequences and methods to avoid them.

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