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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.

Due to the general requirements in the automotive industry to reduce the power consumption, fuel consumption rate and CO2 emission a new HID (High Intensity Discharge) bulb with only 25W is under development for front lighting systems. A first headlamp integrated in a hybrid vehicle is now launched as a first application in the market. The current regulation in ECE allows to get rid of the mandatory headlamp cleaning system and the automatic leveling requirement once the 25W HID bulb is applied. The reason for this is the objective luminous flux of the 25W HID bulb, which emits less than 2000 lm, a boundary defined in the regulation, where a headlamp cleaning and an automatic leveling is requested. That simplifies especially the integration in smaller vehicles and electric and hybrid vehicles. The paper describes the special design of the headlamp, the projector unit, the light performance, packaging advantages and future outlook of further applications in the near future.

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.

The new 5480 Reach Truck, designed at Dynamic Industries, introduces a movable frame between the main frame and the telescopic boom. The use of this movable frame allows the usually fixed boom pivot to be elevated for greater lifting heights with smaller boom sections. By combining the motions of the boom and the movable frame, horizontal motion at the boom tip is possible without moving the truck. With the movable frame, the total machine height and length can be reduced for a given lifting goal. Another advantage of the movable frame is the ability to reach further below grade than is now possible in the industry. The 5480 Reach Truck has a maximum lift of 54 feet (16.5 meters) and can reach 24 feet (7.3 meters) below-grade.

A unique shuttle bus is being constructed by Minicars, Inc., and Walter Vetter Karosserie-werk for Denver’s Transitway/Mall. The bus is designed for frequent stop, low speed service in a downtown pedestrian environment. It features a very low floor and multiple wide doors for rapid passenger boarding and deboarding. Two versions will be supplied for comparative evalation, a low noise diesel configuration and a battery-electric configuration. Either version can subsequently be converted to the alternative propulsion system.

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.

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.

“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.”

The classical methods of deflection analysis are finding more application to complex automotive chassis frame structures. Much too time consuming for manual application, they are now coming into more widespread use with the aid of high-speed computers. This paper describes a computerized deflection analysis for complete truck frames under the cases of torsion and flexure. The rapid, accurate analysis permits investigation of more design problems resulting in the eventual production of more efficient frame structures.

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].

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.

A rear-steering control method for a four-wheel steering truck has been developed. The purpose of this investigation is to develop a control method to minimize the turning radius without the excursion of the vehicle rear end toward the outside of the turn. The basic control concept is to steer the rear wheels so that the vehicle rear end follows the path of the front end. The control method was applied to an experimental medium-duty truck with four-wheel steering system. The simulation and vehicle test results showed the control method to be effective in minimizing the turning radius without causing the excursion of the vehicle rear end toward the outside in short turns.

Current trends in environmental and emissions regulations are driving changes in new engine systems, and increasing the need for more effectively sealed joints in exhaust systems. At the high temperatures in these exhaust systems it is difficult for traditional gaskets to provide an effective seal, as they degrade at high operating temperatures. This paper introduces a coating that has both excellent temperature stability and good compliance, thus forming an excellent sealing enhancement for metallic layers in exhaust system gaskets. Temperature stability data is presented along with sealing data, which illustrate the superior performance of this material compared to current systems.

Environmental concerns and government regulations are factors that have led to an increased focus on fuel economy in the automotive industry. This paper identifies a method used to improve the efficiency of a front-wheel-drive (FWD) automatic transmission. In order to create improvements in large complex systems, it is key to have a large scope, to include as much of the system as possible. The approach taken in this work was to use Design for Six Sigma (DFSS) methodology. This was done to optimize as many of the front-wheel-drive transmission components as possible to increase robustness and efficiency. A focus of robustness, or consistency in torque transformation, is as important as the value of efficiency itself, because of the huge range of usage conditions. Therefore, it was necessary to find a solution of the best transmission component settings that would not depend on specific usage conditions such as temperatures, system pressures, or gear ratio.

Adjuster rings are used in commercial vehicle axle assembly to preload differential bearings and provide support in the axial direction. Adjuster along with the carrier and bearing cap combined to form a threaded joint. Adjuster with external threads engages with internal threads formed in carrier and bearing cap. Preload in differential assembly maintains the system rigidity and helps to maintain an optimized hypoid gear engagement. An adequate preload is important to achieve a desirable bearing life. Reduction in thread engagement at adjuster joint fully or partially will cause a reduction in preload and can lead to gear misalignment. This can cause severe durability concerns. In some cases, it is observed that under vehicle operating loads adjuster ring is backed off from its assembled condition by bending the split pin (split pin is, positive lock, used to maintain adjuster position) and adjuster threads were stripped off.

The paper describes a simple, modified, direct method for the design of high pressure ratio centrifugal compressor impellers, using a prescribed relative velocity distribution. Based on certain simplifying assumptions, the equations of equilibrium are written in terms of the relative velocity components in the radial, axial and tangential directions. These were then solved in a step by step manner along the mean streamline to give the channel shape. An example impeller is shown, which was designed using this method, its geometric proportions appear to be acceptable.

A direct method is developed for designing a vehicle fuel filler door with torsional spring. The design parameters include the door's geometrical parameters and spring dimensions. The design requirements are based on the finger force curve during closing and opening, and the bending stress in the spring. An example is included to demonstrate the effectiveness of the new method.

This paper presents a method of specifying the essential information for detailing the geometry of an external involute profiled spur or helical gear tooth. Internal gears are not included for reasons stated in the paper. It assumes that the reader is familiar with basic gear design terms and concepts.