Parallel-Axis Gear Design Methodology for Minimization of Power Loss and Its Effect on Vibration Characteristics

Gear tooth strength is mainly considered in gear design to ensure the ability to transmit power. With the design process, various sets of gear parameters are probably selected to meet the tooth strength. However the efficiencies of various designed gears are different. Improper gear parameter selection probably makes the gear power loss increase significantly. In this paper, the design methodology to minimize gear power loss is presented. A spur gear selected from a catalogue is used as the reference gear. Then several gears with various parameters but having the ability to transmit the same load are designed. The power losses of the designed and the reference gears are estimated by the sliding loss model, hence the minimum power loss gear is able to choose from the various designed gear sets. Both analytical and experimental results show that to minimize gear power loss along with keeping loading capacity, pressure angle should be increased and module should be reduced. The effect of this design methodology on vibration characteristics is also investigated by measuring the vibration attributed to the sample gear sets. It is found that the helical gear having large pressure angle, wide face width and having helix angle about 10 to 20 is favorable, since it has more capability to transmit load, lower power loss and also lower vibration than the reference spur gear.