Reduction of Parasitic Losses in Front-End-Accessory-Drive Systems - Part 1 2017-01-0893

Demanding CO₂ and fuel economy regulations are continuing to pressure the automotive industry into considering innovative powertrain and vehicle-level solutions. Powertrain engineers continue to minimize engine internal friction and transmission parasitic losses with the aim of reducing overall vehicle fuel consumption. Strip friction methods are used to determine and isolate components in engines and transmissions with the highest contribution to friction losses. However, there is relatively little focus on friction optimization of Front-End-Accessory-Drive (FEAD) components such as alternators and Air Conditioning (AC) compressors. This paper expands on the work performed by other researchers’ specifically targeting in-depth understanding of system design and operating strategy. Prime focus of the first part of the study is to outline the development of a flexible test stand that allows for highly accurate torque measurements on such components under precisely controlled environmental boundary conditions and device loads. Initial testing results from multiple test units are also presented.

This paper will detail aspects of the test stand design that provide flexibility for adaptation to various test scenarios. The results from measurements for a number of FEAD components will be shown in the context of scatterbands derived from multiple component tests. Key results from direct-drive and belt-driven component tests will be compared to illustrate the influence of the belt layout on mechanical efficiency of the FEAD system.