Although the efficiency of a gear pair is currently high, a better understanding of surface/lubricant contribution on efficiency is critical. Electrified drivelines will, for example, impose higher speed and alternate loading, and it is expected that these new conditions will, to a greater extent, rely on the surface/lubricant characteristics. Phenomena taking place in the gear contact is often measured using ball-on-disc and twin-disc tribometers. In this study, these two test set-ups were compared in order to assess differences in the behaviour of surface/lubricant interactions. Results showed that ball-on-disc and twin-disc set-ups reflect the same friction trends. However, the friction results differed by a factor of roughly two, even though the tribometers were set-up to run at the same contact pressure. The wear mechanisms also differed: micropits occurred on discs used in the twin-disc set-up, whereas normal or no wear was found on the ball-on-disc specimens. The contact conditions for the two test set-ups were also analysed using a numerical model. The comparison of these two machines may aid gear designers in selecting the proper experimental set-up for their purpose.

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, we propose a new clustering-based method for product modularization that integrates product complexity and company business strategies. The proposed method is logically verified by a studied industrial case, where the architecture of a heavy truck driveline is analyzed in terms of how it has evolved over a couple of decades, due to changed business strategies and the evolution of new technology. The presented case indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, the case study clearly shows that the business strategic reasons for a specific architecture can be found by analyzing how sensitive the clusters are to changes in the module drivers (MD).

With regard to airborne particles with an aerodynamic diameter of less than 10 mu m (PM10), in countries in the European Union, the mass of brake emissions equals approximately 8-27% of the total traffic-related emissions. Using a research methodology combining tests at different scale levels with contact mechanics simulations and PM10 chemical characterization, the REBRAKE EU-financed project had the following aims: i) to demonstrate the possibility of reducing the PM10 fraction of the airborne particulate from brake wear by 50 wt%; ii) to enhance the general understanding on the physical and chemical phenomena underlying the brake wear process. The results achieved so far indicate that it is possible to design a disc brake system for a European standard car affording at least a 32 wt% PM10 emission reduction using a standard European pad and a heat-treated rotor. A further reduction to 65 wt% PM10 emission could be achieved with NAO pad material and the same heat-treated disc.

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, a heavy duty modular gearbox architecture is represented and analyzed. In focus is re-engineering of hidden technical complexity and business strategy concerns behind an existing product architecture. The architecture of the investigated gearbox is represented and analyzed with a Product Architecture DSM and the Integrated Modularization Method (IMM). Furthermore, a Cluster Match Matrix (CMM) is proposed as a means to compare multiple clustering results. The case study indicates that the IMM methodology and CMM can be used for analyzing and finding the explicit and/or implicit reason for a targeted existing product architecture.

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, we propose a new clustering based method for product modularization that integrates product complexity and company business strategies. The proposed method is logically verified by a studied industrial case, where the architecture of a heavy truck driveline is analyzed in terms of how it has evolved over a couple of decades, due to changed business strategies and the evolution of new technology. The presented case indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, the case study clearly shows that the business strategic reasons for a specific architecture can be found by analyzing how sensitive the clusters are to changes in the module drivers.

A modular architecture is a strategic means to deliver external variety and internal commonality. A methodology for product modularization that integrates complexity and strategies is proposed and logically verified with an industrial case from the heavy truck business area. The case study indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company specific strategies.

An important contributor to non-exhaust emissions in urban areas is airborne particulate matter originating from brake systems. A well-established way to test such systems in industry is to use inertia dynamometer benches; although they are quite expensive to run. Pin-on-disc tribometers, on the other hand, are relatively cheap to run, but simplify the real system. The literature indicates promising correlations between these two test stands with regard to measured airborne number distribution. Recent studies also show a strong dependency between the airborne number concentration and the disc temperature. However, a direct comparison that also takes into account temperature effects is missing. The aim of this paper is, therefore, to investigate how the transition temperature is affected by the different test scales, under dragging conditions, and the effects on total concentration and size distribution. New and used low-steel pins/pads were tested against cast iron discs/rotors on both the aforementioned test stands, appositely designed for particulate emission studies. A constant normal load and constant rotational velocity were imposed in both test stands. Results show that a transition temperature can always be identified. However, it is influenced by the test scale and the frictional pair status. Nevertheless, emissions are assessed similarly when an equivalent frictional pair status is analysed (e.g. run-in). Further investigations for fully run-in samples on the pin-on-disc should be performed in order to finally assess the possibility of using the tribometers for the initial assessment of different friction materials.

A common view is that a module should be a functional building block, with well-defined and standardized interfaces between the modules, and that it should be chosen for company specific reasons. A modular product architecture is a strategic means to deliver external variety and internal commonality. Today, multiple modularisation methodologies exist to support the highly complex task to identify module candidates in the product architecting phase. One methodology is Modular Function Deployment with the Modular Indication Matrix (MIM) representation of company-specific module drivers. Other methodologies, such as Design Structure Matrix (DSM) clustering, may be used to identify modules from a technical complexity point of view. In this paper, the performance of the newly proposed Integrated Modularization Methodology (IMM), which is based on clustering of a strategically adapted DSM, is conceptually verified. The core of the IMM is to transfer company specific module drivers from the MIM into the component-DSM, before clustering this hybrid representation. A re-architecting industrial case, where a truck manufacturer with a unique business strategy had to redesign parts of its modular gearbox architecture to also become a First-Tier OEM-supplier to another large truck manufacturer, is used as test bench. Reverse engineering of the investigated gearbox architecture indicates that the current modules are most likely not only based on technical complexity concerns. They are rather derived from different types of business strategic aspects, e.g. outsourcing. The study also indicates that the IMM is capable of identifying clusters without strategic conflicts, and with the most similar result to the analysed architecture, which is assumed to be based on expert judgements.