Modeling Fuel Economy Improvements from Variable Speed Accessory Drives

In current military and civilian ground vehicles, accessory components are designed to work across a large range of rotational speeds. This typically results in accessories that are over-sized. Consequently, efficiencies suffer over a significant portion of the accessory operational range. A variable speed drive would enable accessory components to operate at optimal speeds across the full range of engine speeds. The objective of the proposed research effort is to demonstrate through modeling and simulation that cost-effective fuel efficiency gains are achievable through optimization of engine accessory speeds using a variable speed drive in an MTVR (or equivalent) vehicle. The proposed research will explore through analysis the tradeoffs of accessory optimization and identify accessories that can be optimized within the cost constraints and customer requirements. Orbital Traction believes that its continuously variable transmission technology, applied to accessory drive systems, will provide the following benefits: Significant fuel economy improvements (above electrification). Integration within the existing engine compartment of most vehicle platforms. Low cost and low complexity implementation. Appropriate ratio coverage with a high level of transmission efficiency.