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Parameters like brake mean effective pressure, mean velocity of the piston, hardness of the wear surface, oil film thickness, and surface areas of critical wear parts are similar for all the diesel engines. The mean piston velocity at the rated speed is nearly the same for all the diesel engines. The mechanical efficiency normalized to an arbitrary brake mean effective pressure (bmep) is dependent on the size of the engine. The engine life seems to be proportional directly to the square of a characteristic dimension namely, cylinder bore of the engine and inversely to speed and load factor for engines varying widely in sizes and ratings.

A pin and disc machine has been modified for the evaluation of silver-steel lubrication characteristics of railroad diesel oils. Use of silver pins on polished steel discs at selected loads and rubbing speeds allows good correlation with known engine behavior. In comparison with wear and friction data obtained by the four ball method, this pin and disc test gives better correlation with engine tests than the Modified Four Ball Test.

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.

To date, no definitive work to quantify and compare the braking rating horsepower relationships between vehicles equipped with brake assemblies containing asbestos, non-asbestos, and semi-metallic friction material has been completed. This paper will report the results of a brake fade evaluation performed on a 34,000-lb. GVW vehicle in accordance with SAE J880 Brake System Rating Test Code Procedures and has quantified braking horsepower, fade temperature resistance, thermal response temperature rise, lining wear, and drum wear.

“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.”

Aiming at achieving the economy and safety of downhill brake process (running downward along a long slope at a constant velocity) of commercial vehicles, an integrated control strategy of the main brake system and auxiliary brake systems is proposed. Based on Electronic Controlled Braking System (EBS), the strategy distributes braking force to each brake system and each axle according to the thermodynamic feature of them and the wear loss of each brake lining, in order to achieve economy at the premise of safety. A simulation is conducted based on MATLAB/Simulink and TruckSim. Simulation results show that the strategy proposed could control the temperature of each brake system at a rational value, and the balanced wear loss of brake linings is facilitated, thus, the safety and economy of downhill brake is ensured.

Vehicle manufacturers strive hard to achieve best in class fuel economy. Apart from light weighting of the structures, driveline optimization and reduction of tire rolling resistance, tapping of parasitic losses is also important and helps to optimize the design of auxiliary power consuming systems. One of such system studied in this work is power steering system. The effect of parasitic losses on fuel economy is predominant for small commercial vehicle compare to heavy vehicles. The evaluation of deterioration in the fuel economy due to implementation of power steering system on one of the small commercial vehicle is carried out using multiple virtual simulation tools. Virtual route profile is modelled using longitude, latitude and altitude data captured through GPS and steering duty cycle is mapped in terms of steering rotation angle. A system level model of hydraulic power steering system is developed.

Abstract Three-dimensional patterns representing crosshatched plateau-honed cylinder bores based on two-dimensional Fast Fourier Transform (FFT) of measured surfaces were generated and used to calculate pressure flow, shear-driven flow, and shear stress factors. Later, the flow and shear stress factors obtained by numerical simulations for various surface patterns were used to calculate lubricant film thickness and friction force between piston ring and cylinder bore contact in typical diesel engine conditions using a mixed lubrication model. The effects of various crosshatch honing angles, such as 30°, 45°, and 60°, and texture heights on engine friction losses, wear, and oil consumption were discussed in detail. It is observed from numerical results that lower lubricant film thickness values are generated with higher honing angles, particularly in mixed lubrication regime where lubricant film thickness is close to the roughness level, mainly due to lower resistance to pressure flow.

This paper presents a theoretical and experimental study on the determination of the efficiency of a hydraulic gear pump based on an analysis of the hydraulic fluid temperature at the inlet and outlet ports. Considering the thermodynamics and fluid mechanics equations, the steady state behavior of the gear pump is described for different wear conditions. The model establishes the relationship between the inlet and outlet temperatures and the main variables such as pressure, torque, flow, and angular speed and, consequently, the pump efficiency.

A new type of screw pump has inherent design features (e.g. balanced design, low bearing loads, wear-adjustable rotors, low rubbing loads, …) which may allow efficient, reliable, and maintainable operation in numerous applications, particularly for pumping low-viscosity fluids. Initial tests on an 87 gal/min prototype pumping lubricating oil at pressures up to 500 lb/in2 and speeds up to 1800 rev/min achieved good performance with little wear over 3400 hours of operations. Performance projections indicate volumetric efficiencies of 50 percent should be reached using the existing prototype pumping 1200 lb/in2 water in one stage.

Pulse width modulation (PWM) has been used to alter the performance of on-off hydraulic control valves to make them perform as proportional type flow control valves. Nonlinear performance resulting from time delays in valve switching as well as valve wear due to continuous cycling continue to persist as operational problems. This paper examines a new technique called modified PWM control. The method was found to provide accurate control with a minimum of valve chatter.

The objective of this paper is to delineate the importance of pictures, i.e., graphical models, in documenting and communicating the high level functionality of a complex system, primarily for embedded software requirements and specifications. An overview is given of various graphical techniques and methodologies for modeling complex systems. The aspects (advantages and disadvantages) relating to different categories of modeling are outlined. Discussion of complex systems extends beyond the functional/software aspects of product design to both process and project modeling. The author shares personal observations and experiences with modeling, and tools used.

Microplastic deformation associated with rough surface and dents are found to generate tensile residual stress, which can be a source of surface fatigue. Both pre-existing hoop stress and friction-induced lateral normal stress parallel to surface are found to have an effect on the plastic strains and tensile residual stress. This finding can possibly explain many reported experimental observations that in rolling/sliding contact, the slower surface is more susceptible to surface fatigue than the faster mating surface. Micropitting probability and wear volume loss can be formulated based on Mode I crack growth process using the tensile residual stress as the fatigue criterion.

In this study, a six litres displacement, commercial vehicle engine that meets the EURO-5 regulation was used to evaluate the durability and performance deterioration of the SCR system mounted on a heavy-duty diesel vehicle. ESC and ETC modes were used for emission test. Characteristics of emissions by SCR catalyst deterioration were investigated using mileage vehicles of 0 km, 120,000 km, and 360,000 km. EDS (Energy Dispersive X-Ray Spectroscopy) analysis on PM filters and CT scan to catalyst substrate were carried out in order to investigate the status of catalyst by each mileage. As a result, it was found that NOX, slipped NH3 as well as PM due to unreacted ammonia and urea increased as the mileage of the catalyst increased.

Effective requirements elicitation and management is a common need in supplier-OEM relationships, and continues to play a vital role in all aspects of the product development lifecycle. While traditional methods address the business goals for requirements and provide guidance in ensuring the accuracy of the “Descriptive-Prescriptive-Explanatory” outputs for requirements gathering and documentation, engineering organizations continue to encounter challenges with respect to capturing and communicating change, accommodating the addition of relevant design details and efficient propagation to inform development. These challenges become more difficult to overcome in mechatronic systems, which combine mechanical systems with integrated software. As software development can produce an overwhelming volume of information that requires accurate tracking and proliferation, it cannot be effectively managed using traditional hardware-centric systems.

A new oval test track will be designed, constructed and operated in a manner that will successfully pull-together representatives from virtually all of the key interests in dealing with the challenging issues of highway pavement and truck durability. With construction scheduled to begin in the Summer of 1998 and completion scheduled for late 1998 or early 1999, the mission and commitment for this venture is to pull-together the people from several state DOTs, respective universities, and, of vital importance, the truck manufacturing industry. Results from these tests, over a period of a few years, will provide answers that not only greatly improve performance of hot mix asphalt pavements in all state DOTs, but also efficiently and productively address issues of durability and wear performance of medium / heavy duty trucks and key components.

A new Artificial Intelligence (AI) “Expert System” software technology has been developed which shows real promise as the core platform of the Decision Support System for Truck Repair. The “Expert system” consists of a Model Based reasoning mechanism, and a Rule Based shell along with an on-line documentation and graphics capability. This technology combines the development speed and accuracy of Model Based technology, the precision of Rule Based expert systems along with the ease-of-use associated with a “Hypertext” information system.

Low crew productivity and extension of service intervals past design limits are the two major reasons so many heavy equipment PM programs are ineffectual. ALPM, or Assembly Line Preventive Maintenance is an innovative system for equipment servicing, providing management scheduling tools and the necessary controls. The system has a successful track record in a number of severe applications.

This SAE Standard includes complete general and dimensional specifications for those types of pipe, filler, and drain plugs (shown in Figures 1 to 6 and Tables 1 to 4) commonly used in automotive and related industrial applications.