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

Efficiency measurement campaign on gearboxes

The last decade, new concepts of electrical motors with promising efficiency have entered the market. Such an electric motor is connected to the load machine often by means of a transmission system. Considering the energy efficiency of transmission systems, there is a lack of available information on the market. In contrast to electrical motors and drives, there are very few mandatory regulations imposed on these components. Information on efficiency can be occasionally found in catalogs but accepted test procedures are not available. As a result, the reliability of these efficiency values is low and comparison between brands and technologies is impossible. Regulation on energy efficiency on the other hand evolves towards a total system approach. The new European fan directive 327/2011 is an example of such an approach where overall efficiency is considered. Information on the efficiency of mechanical transmission components such as gearboxes and belt drives will be required to assess and optimize the overall system efficiency. Due to the lack of reliable information on energy efficiency of these components, a measurement campaign was set up to test a series of gearboxes. This paper discusses the results of this measurement campaign. Because of the wide variation in types and sizing, the measurements where done on a flexible designed input-output gearbox test bench [1]

Visualizing the efficiency of a continuously variable transmission

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

A review of gear housing dynamics and acoustics literature

A review of the available literature on gear housing vibration and noise reduction is presented. Analytical and experimental methodologies used for bearing dynamics, housing vibration and noise, mounts and suspensions, and the overall geared and housing system are discussed. Typical design guidelines as outlined by various investigators are given

The detection of lubricating oil viscosity changes in gearbox transmission systems driven by sensorless variable speed drives using electrical supply parameters

Lubrication oil plays a decisive role to maintain a reliable and efficient operation of gear transmissions. Many offline methods have been developed to monitor the quality of lubricating oils. This work focus on developing a novel online method to diagnose oil degradation based on the measurements from power supply system to the gearbox. Experimental studies based on an 10kW industrial gearbox fed by a sensorless variable speed drive (VSD) shows that measurable changes in both static power and dynamic behaviour are different with lube oils tested. Therefore, it is feasible to use the static power feature to indicate viscosity changes at low and moderate operating speeds. In the meantime, the dynamic feature can separate viscosity changes for all different tested cases

Total drive train optimization of industrial fans and pumps consider-ing VFD driven motor, transmission and load

Standards and mandatory legislations concerning minimum efficiencies of electric motors have entered our world of electromechanical drive trains over the last years. It was a logical step to consider these elements as they account for the largest amount of energy consumption in the European industry. The European ecodesign measures count for 40% of total estimated savings in electric motors by 2020. However, not only the driving motor has to be considered when it comes to optimizing the drive train efficiency. This paper shows the saving potential in other drive train components based on measurement campaigns during several research projects at Ghent University Campus Kortrijk