Energy efficiency measurement procedure for gearboxes in their entire operating range

Over the last decade, forced regulations and a growing social awareness with respect to energy efficiency have resulted in a renewed interest in the research for high efficient electrical machines. When an electrical motor is coupled to a machine, in many cases a gearbox or belt transmission is used. Research shows a lack of information on energy efficiency of these components. In comparison to electrical motors and drives, there is very few regulation and if efficiency values can be found in catalogues, there is no regulated test procedure available to validate the data. As a result, the reliability of these efficiency values is unknown and comparison between manufacturers and technologies is impossible. In this paper a test bench is proposed to measure the energy efficiency of a gearbox with an accuracy up to 0.4%. The test bench is used to measure the efficiency of gearboxes in their entire speed and torque range. Contour maps are used to visualize these measurement results. Moreover, a measurement campaign using different gearboxes is carried out to compare the energy efficiency in the manufacturers catalogue and the measured efficiency.