Efficiency and Slippage in Draw Gears with Flat Belts

This paper presents the measured energy losses in a draw gear with NE22, XH500, LL2, and CFG flat belts. The ranges of torque capacity, slippage occurrence, and transmission efficiency of selected drive belts are also presented. Knowing the exact values of these parameters allows the selection of the most suitable belts for different applications. In addition, belt manufacturers do not provide these data accurately, leading to machine failures and downtime. The paper describes the dependence of belt efficiency and belt slippage as a function of transmission load. Running transmissions with high slippage values are associated with a significant loss of energy and efficiency, rapid wear of the belt and pulleys, and increased operating temperature. In addition, when flat belts are under excessive load, it is common for the belt to quickly fall off the pulleys, interrupting the operation of machinery and equipment. Experiments on a test bench can accurately determine the energy loss caused by transmission belt slippage. The maximum achievable torque of the belt selected for the study, which differed in construction and materials, was around 6 Nm for LL2, XH500, and CFG and 12 Nm for NE22. Slippage reached values of 0.005 to 0.1, while efficiency ranged between 0.60 and 0.97.