A way of providing steering redundancy for highly autonomous vehicles or vehicles equipped with steer-by-wire systems by steering the rear axle for directional control of the vehicle has been previously proposed. In this study, we further investigate and improve on that concept and validate it through simulation and experimental testing on a vehicle. Consequently, we show that in the case of failure of primary front axle steering system, the vehicle controller steering command (in the case of autonomous driving) or the driver’s steering command (in the case of a steer-by-wire system) can be mathematically manipulated to generate a steering input at the rear axle, which results in the same yaw rate response as if the vehicle was steered from the front, and thus providing a way to control the vehicle should a failure occur in the primary steering system.

Nhila, Amine, Williams, Dan E.

Top transmission engineers project big future for e-axles, advanced motors

20AUTP08_0907/01/2020

A panel of high-ranking transmission and driveline engineers projected outsized adoption for electric-axle (e-axle) technology, as well as significant expansion of other driveline-electrification strategies now being adopted for new or near-future production vehicles. The engineering executives participated in a recent webinar in SAE's Leadership Roundtable series, a virtual event replacing the in-person program planned for April's SAE WCX 2020 conference that was cancelled because of the COVID-19 outbreak. Most of the panel agreed that hybrid and other electrification strategies such as e-axles are the transition from internal combustion-based drivetrains to volume production and sales of battery electric vehicles (BEVs). “Long-term, BEV is going to be the better answer,” conceded Michael Solt, global head, transmission, driveline and axle at FCA USA LLC. But the EV solution - and when volume adoption happens - “depends on which market you're in,” he added.

Visnic, Bill

Measurement Location Optimization of Component TPA Method for Road Noise

2020-01-158106/03/2020

In this paper, an investigation on the application of a non-intrusive on-site component Transfer Path Analysis (TPA) method is presented together with the comparison with a previously performed direct blocked forces method. The latter is the more common method to determine interface forces between active and passive parts of an assembly. Force transducers are placed between the investigated structure and a rigid measurement rig. The presented comparison shows an investigated whether the faster and cheaper TPA method was able to produce relevant results. The TPA method used in this work calculated the force component contributions, without disassembly of the interfaces, through the local stiffness of multiple indicator positions per interface combined with operational measurement. The method is based on the application of an inverse-matrix model. This approach was applied to a vehicle road noise investigation carried out on a roller bench at three different roller speeds. A rough

de Boer, Onno, Iturbe, Javier, Gagliardini, Laurent, Bragado Pérez, Beatriz

Modeling and Analysis of a Heavy Vehicle with Self-Steering Axle

02-13-01-0003

04/21/2020

Commercial vehicles often incorporate self-steering axles to meet the axle load requirements while providing improved maneuverability, reduced off-tracking, and reduced tire and pavement wear. Market forces promote the design of more efficient self-steering axle products with reduced weight and more features. Manufacturers also work to differentiate their products through unique designs and new concepts. Traditional design methods for self-steering axles include empirical and trial-and-error methods to set the steering mechanism design parameters based on known design baselines and prior experience. For innovative new concepts that are too far from the traditional designs, it is desirable to have alternative ways for evaluating the expected performance. This article introduces a reduced-order model that allows the rapid analysis of the steering dynamic behavior of self-steering axles. The model combines a pendulum-like lateral stiffness model with the axle steering dynamics which are

Delorenzis, Damon, Ayalew, Beshah

Setting Preload in Heavy-Duty Wheel Bearings

J2535_201910 (Current)10/07/2019

Truck and Bus Wheel Committee

ERRATUM

03-11-01-0004.110/07/2019

Barday, Denis, Fossier, Charlotte, Changenet, Christophe, Ville, Fabrice, Berier, Vincent

Heavy-Duty Aerodynamic Testing for CO ₂ Certification: A Methodology Comparison

2019-01-064904/02/2019

Aerodynamic drag testing is a key component of the CO2 certification schemes for heavy-duty vehicles around the world. This paper presents and compares the regulatory approaches for measuring the drag coefficient of heavy-duty vehicles in Europe, which uses a constant-speed test, and in the United States and Canada, which use a coastdown test. Two European trucks and one North American truck were tested using the constant-speed and coastdown methods. When corrected to zero yaw angle, a difference of up to 12% was observed in the measured drag coefficients from the US coastdown procedure and the EU constant-speed test. The differences in the measured drag coefficient can be attributed, among others, to the assumptions in the speed-dependence of the tire rolling resistance and axle spin losses, the data post-processing required by each methodology, unaccounted frictional losses in the transmission, the behavior of the automated manual transmission during the coastdown run, and the yaw

Rodriguez, J. Felipe, Delgado, Oscar, Demirgok, Berk, Baki, Cem, Besch, Marc, Thiruvengadam, Arvind, Rexeis, Martin, Röck, Martin

ABS Exciter Ring Location Standardization

J1730_201902 (Historical)02/11/2019

Truck and Bus Wheel Committee

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

Effect of Component Flexibility on Axle System Dynamics

2017-01-177206/05/2017

The prediction and control of gear vibration and noise has become very important in the design of a quiet, high-quality gearbox systems. The vibratory energy of the gear pair caused by transmission error excitation is transmitted structurally through shaft-bearing-housing assembly and radiates off from exterior housing surface. Most of the previous studies ignore the contribution of components flexibility to the transmission error (TE) and system dynamic responses. In this study, a system level model of axle system with hypoid gear pair is developed, aiming at investigating the effect of the elasticity of the shafts, bearings and housing on TE as well as the contribution of flexible bearings on the dynamic responses. The load distribution results and gear transmission errors are calculated and compared between different assumptions on the boundary conditions. The modal characteristics and dynamic responses by assuming simply-support bearing and flexible bearing have also been compared

Qiao, Guan, Wang, Yawen, Lim, Teik, Li, Xuan

A Low Cost Rolling Road for Tire Measurements in a Small Eiffel Wind Tunnel

2017-01-150403/28/2017

Wind tunnel aerodynamic testing involving rolling road tire conditions can be expensive and complex to set up. Low cost rolling road testing can be implemented in a 0.3m2 Eiffel wind tunnel by modifying a horizontal belt sander to function as a moving road. This sander is equipped with steel supports to hold a steel plate against the bottom of the wind tunnel to stabilize the entire test section. These supports are bolted directly into the sander frame to ensure minimal vibrational losses or errors during testing. The wind tunnel design at the beginning of the project was encased in a wooden box which was removed to allow easier access to the test section for installation of the rolling road assembly. The tunnel was also modified to allow observers to view the testing process from various angles. These wind tunnel modifications include replacing the wooden panels with clear Lexan plastic sheets, adding dampening material into the test section connections, and making an easily

Tkacik, Peter, Carpenter, Zachary, Gholston, Aaron, Cobb, Benjamin James, Kennedy, Sam, Blankenship, Ethan, Uddin, Mesbah, Krishna Nukala, Surya Phani

Kinematic Analysis of Tractor-Semitrailer with Split Fifth Wheel Coupling During Low Speed Turning Maneuvers

2017-01-155403/28/2017

Over the years, commercial vehicles, especially tractor-semitrailer combinations have become larger and longer. With the increasing demand for their accessibility in remote locations, these vehicles face the problem of off-tracking, which is the ensuing difference in path radii between the front and rear axles of a vehicle as it maneuvers a turn. Apart from steering the rear axle of the semitrailer, one of the feasible ways of mitigating off-tracking is to shift the fifth wheel coupling rearwards. However, this is limited by the distribution of the semitrailer’s load between the two axles of the tractor; any rearward shift of the fifth wheel coupling results in the reduction of the total static load on the tractor’s front axle and hence available traction. This may in turn lead to directional instability of the vehicle. In the present work, a new model of the fifth wheel coupling is proposed which the authors call Split fifth wheel coupling (SFWC). Here, unlike the Conventional fifth

Jogi, Ajith, Chandramohan, Sujatha

Chicago fire: Dodge puts 375-hp Hemi V8 in Durango SRT

17AUTP03_1003/01/2017

“Performance” SUVs are not a new concept, but FCA's Dodge brand opens a new niche-within-a-niche with the unveiling of the 2018 Durango SRT at the 2017 Chicago auto show, calling it “the fastest SUV in its class.” Dodge officials didn't directly say just who's asking for a grocery-getter SUV with 475 hp (354 kW) and 470 lb·ft (637 N·m) from a 6.4-L (or, more historically relevant, 392-in3) V8 that enables cutting a 12.9-s quarter mile time, but the Durango SRT will be in showrooms for that buyer starting in the fourth quarter. Some of the work of adapting the 6.4-L Hemi for the Durango already was done: it is the same iron-block, pushrod V8 with a 10.9:1 compression ratio that appears in the Jeep Grand Cherokee SRT, which shares its architecture with the Durango.

Visnic, Bill

Study of Different Twist-Beam Axle Configurations in Elastokinematics and Handling Behavior of a Vehicle

2016-36-018410/25/2016

The twist-beam suspension is widely used in vehicles due to the simplicity of its construction, less occupied space and its low manufacturing cost in comparison with multi-link suspension. The difficulties related to the design of a twist-beam axle concern the large number of possible configurations for twist-beam profile and the stiffness adjustment of axle beam and suspension arms. However, design process can be done with the aid of multibody dynamics simulations, by testing several configurations in a virtual way. In this work, a simplified twist-beam suspension model is studied, and the influence of variation of its parameters is analyzed in its elastokinematics behavior and in handling performance of a vehicle.

Morales, Eduardo Domingo

Directional Dynamics of Steering the Third Axle

2015-01-274709/29/2015

With the expectation that means of redundant steering will be necessary for highly autonomous vehicles, different methods of providing redundant steering can be considered. One potential for redundancy is to steer the rear axle for directional control of the vehicle in the event of a failure in the primary steered front axle. This paper will characterize the dynamics of directional control of a three-axle vehicle when steered at the rear, and compare it to a conventionally steered three-axle vehicle. Several compensators are suggested that allow similar vehicle dynamic behavior when steering the rear axle as a driver would expect when steering the front, giving hope that a steerable rear axle can provide acceptable redundancy for a failed primary steering system on the front axle.

Williams, Daniel E., Nhila, Amine

Influence of Inertial Forces and Mass Balancer on Internal Combustion Engine Dynamics

2015-36-032409/22/2015

The combustion engines evolution leads the engine manufacturers look for developments focused on downsizing, more powerful, lighter, with great fuel consumption and less noisy. With special attention to NVH, specifically to vibration issue, this work aims at studying the influence of mass balancer and inertia forces coming from engine components on internal combustion engine dynamics supported by vibration dampers. For mass balancer study several experimental analyses were performed in a dynamometer. The conclusions are obtained by comparison between measured engine displacements with and without mass balancer. In order to study the influence of inertia forces from engine internal components, a mathematical model was developed. In this model the inertia forces act on a rigid body, supported by four vibration dampers and six degrees of freedom. Some modifications are made on engine internal components such as mass and geometry, observing their influence on internal combustion engine

Selim, André Baroni, Nabarrete, Airton

Active Control of Structure-Borne Road Noise Based on the Separation of Front and Rear Structural Road Noise Related Dynamics

2015-01-222206/15/2015

Axle forces from tire-road interaction can excite different structural resonances of the vehicle hence a high number of sensors is required for observing and separating all the vibrations dynamics that are coherent with the cabin noise. Feed-forward road noise control strategies adopted so far rely mainly on capturing these dynamics and thus the number of sensors constitutes one major limitation of this approach. Therefore there is a necessity for reducing the number of sensors without degrading the performance of an ANC system. In the past coherence function analysis has been found to be a useful tool for optimizing the sensor location. In this case coherence function mapping was performed between an array of vibration sensors and the headrest microphones in order to identify the locations on the structure that are highly correlated with road noise bands in the compartment. A vehicle with an advanced suspension system was used for applying the method and defining some locations as

Zafeiropoulos, Nikos, Ballatore, Marco, Moorhouse, Andy, Mackay, Andy

Improved Lane-keeping with Rear Axle Steer

2015-01-158404/14/2015

The classic two-degree-of-freedom yaw-plane or “bicycle” vehicle model is augmented with two additional states to describe lane-keeping behavior, and further augmented with an additional control input to steer the rear axle. A simple driver model is hypothesized where the driver closes a loop on a projected lateral lane position. A rear axle steer control law is found to be a function of front axle steering input and vehicle speed that exhibits high speed stability and improved low speed maneuverability. The theoretically derived control law bears similarity to practical embodiments allowing a deeper understanding of the functional value of steering a rear axle.

Williams, Daniel E.

SLICK SOLUTIONS FOR friction reduction

15AUTP04_0304/01/2015

Suppliers and engine designers are attacking every potential source of internal friction-no longer a “low-hanging fruit”-as the battle to squeeze more mechanical work from less fuel intensifies. Reducing internal friction has always been a priority of powertrain designers, but recently the subject has taken on greater urgency in the crunch to meet tough new global CO2 regulations. In piston engines, friction loss rises with the square of rpm, which is one reason OEMs are “downspeeding” their new engine families. And with their key suppliers, they're digging deeper to find cost-effective solutions to this century-old challenge-from “rollerizing” camshafts to optimizing lubrication schemes, to new gas-cushion shaft seals, to decoupling front-end drive systems. New materials and surface coatings are also enablers. “We looked across the entire propulsion system to find places we could reduce spin and drag losses and minimize internal friction,” said Tim Grewe, GM's General Director of

Brooke, Lindsay

Automotive Engineering: February 3, 2015

15AUTP0202/03/2015

Getting a grip on AWD efficiency The safety and performance benefits of all-wheel drive are undeniable, but so are the penalties of added weight, friction losses, and complexity. Clever axle disconnects and E-axles are driving future AWD developments. E pluribus unum Inputs from many sensors are being combined to give safety systems a true vision of vehicle surroundings, with the resulting sensor fusion becoming a mainstay of autonomous vehicle electronics. Lightweighting poses repair challenges Mass-produced aluminum bodies and mixed-material structures present challenges for assembly and repair, as automakers increasingly pursue these lightweight strategies. Setting the standard Meggitt CTO Emeritus begins term at helm of SAE International, seeks to encourage cross-sector relations, elevate image of SAE as aerospace industry leader.

Definition of Slippage Parameters of Friction Clutches for Different Installation Versions in Tractor Gearboxes

2013-01-289411/27/2013

The aim of the work is to present the methodology for calculating the slippage parameters of friction clutches (the work and the time of slippage) for different installation options of such clutches in tractor gearboxes, and of the tractor acceleration time at different degrees of gear overlap. The authors suggest a universal diagram of tractor acceleration at gear shifting at different degrees of gear overlap in the gearbox, which is true for any interrelation of the times of gearing and slippage of the friction clutch. Based on the mathematical model of the tractor acceleration, suggested by the authors, a methodology was developed for calculating the slippage parameters of friction clutches (the work and the time of slippage) for a variety of installation options of such clutches in the gearbox during gear shifting with varying overlap degrees and the acceleration time of the tractor unit at each gear. The developed universal mathematical model allows defining - at the design stage

Sharipov, Valery, Dmitriev, Mikhail

Using Objective Vehicle-Handling Metrics for Tire Performance Evaluation and Selection

2013-01-074304/08/2013

This paper outlines the development of a simulation-based process for assessing the handling performance of a given set of tires on a specific vehicle. Based on force and moment data, a Pacejka tire model was developed for each of the five sets of tires used in this study. To begin with, simple handling metrics including under-steer gradient were calculated using cornering stiffness derived from the Pacejka model. This Pacejka tire model was subsequently combined with a 3DOF non-linear vehicle model to create a simulation model in MATLAB/Simulink®. Other handling metrics were calculated based on simulation results to step and sinusoidal (General Motors Company) steering inputs. Calculated performance metrics include yaw velocity overshoot, yaw velocity response time, lateral acceleration response time and steering sensitivity. In addition to this, the phase lag in lateral acceleration and yaw rate of the vehicle to a sinusoidal steering input were also calculated. Axle characteristics

Sivaramakrishnan, Srikanth, Taheri, Saied

Setting Preload in Heavy-Duty Wheel Bearings

J2535_201302 (Historical)02/11/2013

Truck and Bus Wheel Committee

TAPERED AXLE COLLAR DIMENSIONS

AS665A (Current)10/03/2012

A-5B Gears, Struts and Couplings Committee

Influence of Lubricant on Impact Load in the Electromechanical Transmission Gear

2012-01-162109/10/2012

In the paper, the new method of switching gears is considered in a car transmission box by changing distance between gear axles. The method has the following advantages: high speed switching gears, no needs of the gears synchronization, and easy automation of the process switching. In this case, difference angle speeds of switched gears produces an impact load in teeth of switched gears. Impact loads can be reduced by presence of oil in switched gears. Three stages of the process switching gears are considered when switching by change distance between gears axles. The analysis of the teeth loading is fulfilled for the most important phases of gear switching. As a result, it is concluded about perspective of a reduction of the dynamic loading of gear teeth due to the presence of the lubricating layer in the most loaded contact zone of gears.

Yakovlev, Peter, Dragunov, Gennady, Gladyshev, Sergey P.

Vertical Load Impact of an Urban Front Engine Bus on the Pavement

2012-36-003405/16/2012

The main objective of this paper is to present the different methods of pavement dimensioning, applied on the Brazilian roads, in order to compare the loads used in the calculation with a real application. It has been used a 4×2 vehicle with the maximum load distribution allowed in Brazil (6 tons in the front axle / 10 tons in the rear axle). It has been instrumented the rear axle with strain gauges to simulate it as a load cell. Measurements were done on a real urban application (Curitiba city - Brazil). Results showed significant differences between the load used in the Brazilian pavement dimensioning methodology and the dynamic vertical load, which could have a direct impact on the pavement lifetime. This paper was supported by three different agency / companies: UNICAMP, Volvo do Brasil and Meritor do Brasil Sistemas Automotivos Ltda.

Yugo Yoshiura Kubo, Pablo, Lan, Alan Eduardo, Nemoto, Marcel Yoshimi, do Rosario Branco, Percival, Biasi Rodrigues, Esequiel, Lima de Paiva, Cassio Eduardo, Guedes Cezar, Fabio Andreassa, Rivero de Stefani, Armando Marcelo

Method of Vehicle Dynamics Analysis by Means of Equivalent Cornering Stiffness for Aerodynamic Forces and Moments

2012-01-021304/16/2012

The dynamic performance of a vehicle traveling at high speeds is affected by the aerodynamic characteristics consisting of lift on front and rear axles, side force, and yawing moment. In order to enable consideration of these aerodynamic characteristics from the early stages of the vehicle development process, it is required that the characteristics are replaced by simple development indices. The study discussed in this paper introduced the concept of equivalent cornering stiffness to analyze these aerodynamic characteristics from the viewpoint of vehicle dynamics. Using this method, it is possible to integrate four aerodynamic characteristics into two variables which are very important to vehicle dynamics. As a result, the interaction between each aerodynamic characteristic is simply expressed in the equations of motion. Moreover the aerodynamic characteristics are dealt with as the same variables which are commonly used in other chassis systems such as suspensions and tires. It can

Shibue, Hideaki, Ogawa, Atsushi, Mashio, Susumu

Heavy Truck Stability with a Trailing Axle Tire Blowout

2012-01-023804/16/2012

Trailing axles, otherwise known as tag axles, are utilized in many states to allow heavy duty dump trucks and cement trucks to maximize their capacity. The trailing axle is an additional axle mounted on an arm on the rear of the truck that can be raised and lowered. When lowered, the axle extends the overall wheelbase of the vehicle and increases the total number of axles, thereby allowing for additional load to be carried without exceeding load-restriction regulations. There are multiple manufactures of trailing axles that utilize different suspension designs. One design uses an articulating axle that is mounted to the framework that lowers it. In this study, the sensitivity of this design to tire blowout on one of the trailing axle tires is studied. Testing was conducted that involved initiating a sudden air-loss event by creating a hole in the sidewall of the tire. The handling response of the vehicle was documented with on-board instrumentation and on-board and off-board video.

Larson, Robert, Cuadrado, Joseph

Development of Front-Wheel-Drive ELSD for Efficient Performance and Safety

2012-01-030504/16/2012

The open (standard) differential provides an important function in vehicle dynamics and handling by splitting the applied driveline torque and allowing each wheel or axle to spin at different speeds. This function is necessary to eliminate axle bind-up while negotiating turns. However, it inherently impedes optimal traction and mobility performance by allowing the available torque to be limited by the wheel or axle having the least amount of traction. Loss of traction could result in loss of driveline torque control and a resulting loss of vehicle control. This loss of control could be catastrophic in the case of higher speed maneuvers. The proposed electronically controlled hydraulic limited slip differential solution corrects this problem, seamless to the driver, while maintaining the fundamental open differential function. Furthermore, this system maintains efficient forward motion compared to other solutions that slow the vehicle down while expending valuable energy. A number of

Fox, Matthew, Grogg, John

Correlation of Axle Build Parameters to End-of-Line NVH Test Performance Part II: Multivariate Regression Analysis

2012-01-072804/16/2012

The second part of a detailed examination of multivariate correlation of several axle assembly and component parameters to the assembly NVH performance (vibration) measured at the end of the assembly process is presented focusing on the multivariate linear regression analysis. The study is based on test results and measurements acquired from multiple axle assemblies built with the same hypoid gearset, thus effectively eliminating the affect of gearset variation on the test result. Several major components within the axle are considered including the differential housing (that controls wheel differentiation during turns), the axle housing, and several assembly parameters. Details of the multivariate regression include formulation of the linear regression model, model refinements through analysis of subsets of the variables, tests of significance and residual analysis. The first part of this work presented the analysis preparing the data for the regression analysis including checks for

Meinhardt, Glenn, sengupta, Sankar

Correlation of Axle Build Parameters to End-of-Line NVH Test Performance Part I: Preparing the Data for Multivariate Regression Analysis

2012-01-072704/16/2012

The first part of a detailed examination of multivariate correlation of several axle assembly and component parameters to the assembly NVH performance (vibration) measured at the end of the assembly process is presented focusing on preparing the data for multivariate regression analysis. The study is based on test results and measurements acquired from multiple axle assemblies built with the same hypoid gearset, thus effectively eliminating the affect of gearset variation on the test result. Several major components within the axle are considered including the differential housing (that controls wheel differentiation during turns), the axle housing, and several assembly parameters. In Part I (this work), details are presented of the preparation of the data for multivariate regression analysis include assessment of variation within the variables (their candidacy for regression analysis) necessary transformations, examination of univariate and multivariate normality, assessment of

Meinhardt, Glenn, sengupta, Sankar

Method of Vehicle Dynamics Analysis by Means of Equivalent Cornering Stiffness for Aerodynamic Forces and Moments

2012-01-0213-TEST-REC04/16/2012

Shibue, Hideaki, Ogawa, Atsushi, Mashio, Susumu

Tire Wear Improvement by Steering a Third Axle

2011-01-214809/13/2011

The conventional rear tandem axle of a three-axle vehicle produces a yaw resisting moment that adversely impacts vehicle performance. This work examines the effect of steering the rear axle on tire wear. Using actual vehicle test data, a tire wear model is developed. This tire wear model is then used to predict tire wear savings over an actual commercial vehicle duty cycle when the rear axle is steered. The result of this projection is shown to be consistent with reported third party field experience.

Williams, Daniel

Passenger Car and Light Truck Axles

J2200_201109 (Current)09/06/2011

SAE IC Powertrain Steering Committee

High-Performance Differentials, Axles, & Drivelines

C111307/27/2011

Every automobile has a differential and most have axles, yet the exact function of these is not common knowledge. This comprehensive seminar introduces participants to the function and interfaces of axles and their individual components. As we modify cars for street performance or all out race applications, it is important to know the trade-offs in the drivetrain system. The theory and practice of axle systems is introduced along with a hands-on style approach to repairing and modifying axles for high performance applications. For this hands-on approach, actual hardware will be reviewed in an informal setting. The seminar begins by defining the axle fundamentals and operation followed by an in-depth review of original equipment axles, differentials, torque bias, hypoid gears, and rebuild steps. The different manufacturing and service techniques required for different gear architectures is also reviewed. The seminar concludes with a unique applications-specific workshop and industry

Motor Truck CA Dimensions

J691_201106 (Current)06/13/2011

Truck and Bus Total Vehicle Steering Committee

Trailer Axle Alignment

J875_201106 (Current)06/13/2011

The scope of this SAE Recommended Practice, trailer axle alignment, is to identify the dimensional limits of, and a method to, establish a perpendicular relationship between the king pin centerline and the axle centerline at its midpoint. Various types of equipment are commercially available which can be used for this measurement which provides varying degrees of accuracy, but none can be endorsed by SAE. The most fundamental methods of measurement will be described here, but other equipment is available if a greater degree of accuracy is desired.

Truck and Bus Total Vehicle Steering Committee

Signal Analysis Techniques to Identify Axle Bearing Defects

2011-01-153905/17/2011

Vehicle NVH (Noise Vibration & Harshness) is of continued concern to customers in this increasingly competitive market and driveline NVH performance is a key factor in overall vehicle quality. A typical way to increase this quality is the use of axle end of line test stands that utilize NVH signal analysis methods to offer pass/fail criteria. In the manufacturing environment there are high costs associated with axle assemblies that are rejected due to the amount of time for NVH analysis to determine root cause for the failure. Of more interest to both product development and manufacturing activities is the ability to understand the root cause of the failures from the axle end of line test stand. This information can improve the manufacturing process by eliminating errors, streamlining re-build activities, aiding in product design improvements, and in turn reducing cost. This paper describes the activities used to identify specific bearing defects for rear axle application through

Rinaldi, Giovanni, Catenacci, Gino, Freeman, Todd, Goodes, Paul

Development of 4 Wheel Active Steer

2008-01-049504/14/2008

4 wheel Active Steer (4WAS), which controls all four steering angle, is developed first in the world. This system achieves dynamic performance with secure and invigoration feel on higher level, based on active steer technology of rear axle. This paper describes aim and necessity of all four steering control, and introduces outline and efforts of this system.

Katayama, Takeshi, Yasuno, Yoshiki, Oida, Tomoaki, Sao, Masayuki, Imamura, Masayuki, Seki, Nagatoshi, Satou, Yasuharu

Pitch Comfort Optimisation of a Front End Loader using a Hydropneumatic Suspension

2007-01-426910/30/2007

Front end loader vehicles are prone to excessive pitching when travelling at high speed, partly due to the absence of axle suspension. This paper studies the fundamental design of a hydropneumatic suspension for a medium wheel loader. The vehicle is analysed using an analytical frequency response model as well as multibody simulations. Results show that favourable pitching response can be achieved by increasing the rear axle stiffness, but also that a similar effect is achieved with higher front axle stiffness. For the loaded vehicle, it is also found that the benefits of an optimal stiffness distribution are offset to some extent by the reduction in relative damping as the vehicle mass and inertia increases. Thus, it is desirable to increase suspension damping under load to maintain a suitable level of relative damping.

Rehnberg, A., Drugge, L.

Park Standard for Automatic Transmissions

J2208_200710 (Historical)

10/22/2007

To provide a Recommended Practice for validating the function and integrity of an automatic transmission park mechanism with its associated control system and environment.

Automatic Transmission and Transaxle Committee

Component Nomenclature—Articulated Log Skidder, Rubber-Tired

J1109_200708 (Historical)

08/22/2007

This SAE Standard includes names of major components and parts particular to this type of machine. Illustrations used here are not intended to include all existing commercial machines, or to be exactly descriptive of any particular machine. They have been chosen to describe the principles to be used in applying this document (see Figures 1 and 2). 1 Engine 2 Sweep 3 Operator Enclosure 4 Seat 5 Rear Frame 6 Winch 7 Arch 8 Fairlead 8(a) Main Fairlead Roller 8(b) Auxiliary Fairlead Rollers 9 Tire 10 Rim 11 Axle 12 Driveline 13 Steering Cylinder 14 Front Frame 15 Blade Arm1 16 Blade 17 Decking Lug 18 Blade Cylinder 19 Radiator 20 Log Bumper

MTC4, Forestry and Logging Equipment

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