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Hybrid electric vehicles (HEVs) are worldwide recognized as one of the best and most immediate opportunities to solve the problems of fuel consumption, pollutant emissions and fossil fuels depletion, thanks to the high reliability of engines and the high efficiencies of motors. Moreover, as transport policy is becoming day by day stricter all over the world, moving people or goods efficiently and cheaply is the goal that all the main automobile manufacturers are trying to reach. In this context, the municipalities are performing their own action plans for public transport and the efforts in realizing high efficiency hybrid electric buses, could be supported by the local policies. For these reasons, the authors intend to propose an efficient control strategy for a hybrid electric bus, with a series architecture for the power-train.

This paper summarizes the techniques and guidelines which were used to reduce the driver perceived noise level of a 145-210 HP series of agricultural tractors. Graphs of case study test results and comments on subjective noise quality are provided to guide the acoustic novice through the complexities of the vehicle sound environment in a methodical problem solving format.

This SAE standard establishes the minimum construction and performance requirements for a 15 Pole Connector Between Towing Vehicles and Trailers, for trucks, trailers, and dollies in conjunction with SAE J2742. The connector accommodates both power and ISO 11992-1 signal circuits along with dual ground wires to accommodate grounding requirements within the constraints of the SAE J2691 terminal capacity.

Fixed displacement pumps will continue to be a popular choice for hydraulic system designers for decades to come. These pumps are used in almost every industrial and mobile market segment and are generally less expensive than comparable variable displacement type pumps. Fixed displacement “Vane Type” pumps are especially popular because of their low noise characteristics as well as their inherent repair features. The demand for “Vane Type” fixed displacement pumps continues to grow in all market segments. Because of this continued demand, a new design of “fixed displacement vane pumps” is being developed. These pumps, designated the VPF Series, are targeted to offer continuous operating pressures up to 280 BAR with displacements from 40 to 215 cc/rev.

Abstract Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in order to adapt to the requirements of internal combustion engines. An understanding of the working mechanisms as well as an understanding of the way that losses occur in the flow allows a reduced development effort during the optimization process. This article presents three-dimensional (3D) Computational Fluid Dynamics (CFD) investigations of the loss mechanisms and quantitative calculations of individual losses. The 3D-CFD method used in this article will reduce the drawbacks of one-dimensional calculation as far as possible. For example, the twist of the blades is taken into account and the “discrete” method is used for loss calculation instead of the “average” method.

Two new 4 X 4 drivetrain systems have been developed for highway tractors that are used to pull multiple trailer combinations. The first one is a 4 X 2 that automatically becomes a 4 X 4 when conditions exist that require 4 X 4 operation. The second one is a full-time 4 X 4 that proportions the drive torque 36% to the front axle and 64% to the rear axle. A unique front driving steering axle has also been developed that permits a 4 X 4 system to be installed in a standard 4 X 2 truck. There is no need to relocate any major components to make space available for a front driving steering axle.

Diesel injection equipment is required to be more accurate and higher in pressure to meet the increasingly strict emission, fuel consumption regulations and higher engine performance. It also needs to achieve a number of requirements such as robustness against diversified market fuels, easy installation to engine, etc.

A 3-dimensional procedure has been developed to apply the Driver's Eye Range standard and the interior environment section of the Field of View standards. The procedure uses line-of-sight as a more accurate method of locating and creating the information required. This method produces a truer representation of what is seen and allows for expansion into other obstructions. The procedure can be enhanced with computer macros to shorten the time required to produce these studies.

A braking force distribution strategy in integrated braking system composed of the main braking system and the auxiliary braking system based on braking pad wear control and hitch force control under non-emergency braking condition is proposed based on the Electronically Controlled Braking System (EBS) to reduce the difference in braking pad wear between different axles and to decrease hitch force between tractors and trailers. The proposed strategy distributes the braking force based on the desired braking intensity, the degree of the braking pad wear and the limits of certain braking regulations to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers. Computer co-simulations of the proposed strategy are performed.

A cartridge type pivotal pin and bushing joint has been patented and is being tested and refined both in the laboratory and on construction machinery. It features “dry lubricated” (Teflon) bearings which are assembled and sealed prior to installation. It is suitable for heavy unit loads and use under severe wear conditions, such as in crawler track chains and loader bucket pivotal pin joints. A brief history of U. S. manufactured track pin joints is included to show the progress in extending the service life of these devices.

In the recent years, Electric-mobility has been a trending aspect in the transportation sector. Increase in the air pollution by the use of combustion vehicles resulted in the initiation of various subsidiaries and norms by the governments across the world. To bring an eco-friendly transportation, many cities across the world are trying to incorporate the electric vehicles in the public transportation system. In India, State Road Transport Undertakings (SRTU’s) have started adopting electric buses. One of the critical requirement for successful operation of electric vehicles is charging infrastructure, which is required for charging the vehicles. There are various charging technologies available in the industry. This paper presents a case study for evaluating pantograph based electric bus charging systems for Patna project and compares the charging schedule, charger infrastructure sizing, CAPEX and OPEX with respect to traditional proven CCS2 charging technology.

The paper addresses some aspects of an ongoing research on a commercial compact excavator. The interest is focused on the analysis and modelling of the whole hydraulic circuit that, beside a load sensing variable displacement pump, features a stack of nine proportional directional control valves modules of which seven are of the load sensing type. Loads being sensed are the boom swing, boom, stick and bucket, right and left track motors and work tools; instead, the blade and the turret swing users do not contribute to the load sensing signal. Of specific interest are the peculiarities that were observed in the stack. In fact, to develop an accurate AMESim modelling, the stack was dismantled and all modules analysed and represented in a CAD environment as 3D parts. The load sensing flow generation unit was replaced on the vehicle by another one whose analysis and modelling have been developed using available design and experimental data.

Engine mounts are an integral part of the vehicle that helps in reducing the vibrations generated from the engine. Engine mounts require a simple yet complicated amalgamation of two very different materials, steel and rubber. Proper adhesion between the two is required to prevent any part failure. Therefore, it becomes important that a comprehensive study is done to understand the mating phenomenon of both. A good linking between rubber and metal substrate is governed by surface pretreatment. Various methodologies such as mechanical and chemical are adopted for the same. This paper aims to present a comparative study as to which surface pretreatment has an edge over other techniques in terms of separation force required to break the bonding between the two parts. The study also presents a cost comparison between the techniques so that the best possible technique can be put to use in the commercial vehicle industry.

Despite the general similarity of U.S. and European heavy trucks, there are differences in design properties that affect braking and turning performance. A European tractor-semitrailer was studied for the purpose of comparing its properties to those of U.S. vehicles and assessing the comparative performance. Mass, suspension, and braking system properties of the European tractor and semitrailer were measured in the laboratory and on the proving ground. Turning and braking performance qualities were evaluated by computer simulation and by experimental tests. In turning performance the European combination had a 9 percent advantage in rollover threshold, compared to a generic U.S. vehicle with properties that were in the midrange of U.S. design practice. Higher suspension roll stiffness and higher chassis weight on the European tractor and semitrailer accounted for the higher threshold.

Regulatory requirements in the European Union (EU) for off-road machines and road vehicles are different. Vehicles which transport passengers and goods, along with attached trailers, as well as road motorcycles must meet EEC type-approval requirements. All other types of self-propelled machines must meet the requirements of the Machinery Directive (Council Directive 98/37/EC), and the Electromagnetic Compatibility (EMC) Directive (Council Directive 89/336/EEC) and possibly other directives. This includes such categories as agriculture and forestry machines, construction machines, industrial trucks and similar products. The various directives outline the different processes for demonstrating compliance with the EU requirements. The intent of this paper is to summarize a few of the requirements that are of interest to off-highway equipment manufacturers and to identify some sources of information about the regulatory requirements.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

A Computer Aided System (CAS) is developed in order to evaluate off-road wheeled vehicle mobility. The system takes into consideration both vehicle technical parameters and the main specifications of the soil on which the vehicle is expected to operate. Thirty seven vehicle technical parameters organized in nine groups are considered. These groups are: weights, engine parameters, dimensions, performance, transmission, steering, brakes, tires, and self recovery means. The main soil specifications of the soil considered are the soil type (clay, silt, or sand) and the shear and bearing resistance represented by the cone index or the gradient cone index. The evaluation process depends on considering a datum value for each vehicle technical parameter. These datum values or norms are obtained from a statistical analysis study of the technical parameters for a sample of 155 off-road wheeled vehicles representing different schools from all over the world [1].

A class of heavy truck vehicles, characterized primarily by high centers of gravity, was studied using analysis and computer simulation to identify and understand the relationship between directional and roll stability of such vehicles during steady turning maneuvers. Findings of the computer-based study suggest: (1) directional instability (yaw divergence) is possible for such vehicles during steady turning while operating at elevated speeds on horizontal road surfaces, (2) yaw divergence will lead to rollover in the absence of corrective steering action and/or reduced speed, and (3) the primary mechanism responsible for precipitating yaw divergent behavior in such vehicles is the nonlinear sensitivity of truck tire cornering stiffness to vertical load acting in combination with typical heavy truck fore/aft roll stiffness distributions. In addition, the influences of roadway superelevation and driver steering control as contributors to vehicle stabilization are examined and discussed.

Predicting fatigue performance in concentrated contacts under thin film (or mixed) lubrication conditions has historically involved various empirical approaches. Typically a lubrication parameter is used in an experimentally derived equation to predict the expected rolling contact performance. However, this model doesn't explain the performance improvements. Enhanced finish bearings have exhibited longer life than standard finish bearings, especially when bearings are operated with thin EHL film. In this paper, the contact surfaces of test bearings were analyzed by using a micro-macro contact model in which the macro-contact was elastic contact, and the micro-contact was elastic-plastic contact. The interior subsurface stress maps were calculated from the real contact surfaces, which included the effects of roughnesses, waviness, and profiles.