Experimental study of the influence of tooth profile modifications on spur gear dynamic strain and vibration

Noise and vibration that are generated in a gear transmission system are caused by transmission error. The transmission error arises from some errors that occur during manufacturing or called as manufacturing error, tooth deflection under load, structure deflection and distortions that occurs during operation. The transmission error due to tooth deflection can be reduced by performing gear profile modification. The shape and amount of gear tooth modification depend on load and error during manufacturing. This experiment uses four pair of gears. One of the pairs is gears without tooth profile modification. The other three of pairs experience tooth profile modification of long parabolic, intermediate parabolic and linear. In this experiment, the dynamic load is measured as the strain on the tooth root fillet. This measurement is carried out by installing a strain gage on the pairs of gears. Experimental result shows that strain occurring on the modified tooth profile gears is lower than on standard tooth profile until 50% , and this occurs on the tooth profile modification of the intermediate parabolic. Vibration measurement shows that the spectrum of long parabolic profile modified tooth has lower amplitude (measured on gear mesh frequency) especially under high load. The intermediate parabolic profile is higher in amplitude, and the linear profile is slightly lower in amplitude , respectivelly, compared with unmodified gear.