Abstract:
This thesis presents the preliminary study on parameters affecting to power losses in helical gears. This study is separated into two parts that are application of the mathematical model for estimating power loss of helical gear transmission and experiment to investigate the helical gear power loss. First the spur gear meshing model presented by Chanat has been improved, helical gear is modeled as the multi-section spur gears aligned slantwise along with base helix angle. The second part; experiment; the back-to-back gear test rig had been constructed for measuring helical gear power loss. This type of the test rig does not have the power output. The input power is circulated in the system to compensate the friction and power losses. In order to verify the accuracy of the model, the estimated power losses were compared with the experimental results. The parameters affecting to power loss considered here are helix angle, pressure angle, face width and module. The estimated results shows that the helical gear pair having higher helix angle and module has higher power loss but helical gear with higher pressure angle and face width has lower power loss. By comparison between the estimated and experimental results, it is found that the estimated results agree well with experimental results just only in case of affects of pressure angle and module, however the affects of helix angle and face width to power loss cannot be predicted correctly.