This paper investigates how the efficiency of a Continuously Variable Transmission (CVT) can be visualized in a compact way. At this point there is no standardized method to describe CVT efficiency as there are many inputs which affect the efficiency. Input speed, load torque, speed ratio and clamping force have been identified as dominant factors influencing efficiency. By analyzing the impact of each parameter a method is proposed based on an efficiency map and a scaling law. Efficiency maps are used because they represent the efficiency in the complete operating range and not only in the optimal conditions. The results of this study are of importance for constructors and end users of CVTs. The constructors benefit from the fact that they can plot the efficiency data in a compact format while the end users can use the data to optimize their drivetrain. The approach where efficiency data is used by the end users to optimize the drivetrain in terms of efficiency is called the Extended Product Approach (EPA). By implementing EPA in the design process, large savings on the long term are possible.
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