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V. Otipka et al.
during traction mode simulation. Gear rattle manifests itself in a narrow time area
where a wide band of frequencies are excited. Basic components of the signal can
also be recognized on the multispectrum diagram—shaft and pinion rotary frequency,
tooth frequency and their harmonic orders. Other areas of increased amplitudes are
caused by the intersection of excitation frequencies and the natural frequencies of
the individual components of the transmission.
4 Conclusion
As already mentioned, optimizing gearboxes in terms of vibro-acoustics is a complex
issue. In this paper, the approach of changing the gearbox geometry to surface
vibration was presented.
The greatest increase in gearbox surface vibration in a presented configuration
during operation occurs due to gear rattle effect. The design changes were intended
to reduce amplitudes of surface normal velocities in areas of interest. Only due to
design optimization of the housing, the amplitudes in these areas were reduced by
more than 20%.
Further reduction of vibration could be achieved by optimizing the modal properties of all components included in the model to minimize intersections of their
natural frequencies. It is also possible, for example, to optimize the macro and micro
geometry of the gears or to use a lubricant with different parameters.
This computational model is a suitable tool for the initial prediction of the dynamic
behaviour of the transmission. However, the level of the presented model can still
be increased by including new influences. For example, including the moments of
inertia from the entire drive chain, it is also possible to cover the input speed character
or to include in-service shocks.
The results have not been validated by propriety experiment yet. Several technical
experiments are going to be performed to obtain corresponding data about vibrations
and transmission error. Real measured data are very useful for verification of computational model, because the results obtained from computational model are highly
dependent on the input parameters from the user.
Acknowledgements The research leading to these results has received funding from the project
FSI-S-17-4104 granted by specific university research of Brno University of Technology and
Project TH02010725 granted by Technology Agency of the Czech Republic. The authors gratefully
acknowledge this support.
V. Otipka et al.
during traction mode simulation. Gear rattle manifests itself in a narrow time area
where a wide band of frequencies are excited. Basic components of the signal can
also be recognized on the multispectrum diagram—shaft and pinion rotary frequency,
tooth frequency and their harmonic orders. Other areas of increased amplitudes are
caused by the intersection of excitation frequencies and the natural frequencies of
the individual components of the transmission.
4 Conclusion
As already mentioned, optimizing gearboxes in terms of vibro-acoustics is a complex
issue. In this paper, the approach of changing the gearbox geometry to surface
vibration was presented.
The greatest increase in gearbox surface vibration in a presented configuration
during operation occurs due to gear rattle effect. The design changes were intended
to reduce amplitudes of surface normal velocities in areas of interest. Only due to
design optimization of the housing, the amplitudes in these areas were reduced by
more than 20%.
Further reduction of vibration could be achieved by optimizing the modal properties of all components included in the model to minimize intersections of their
natural frequencies. It is also possible, for example, to optimize the macro and micro
geometry of the gears or to use a lubricant with different parameters.
This computational model is a suitable tool for the initial prediction of the dynamic
behaviour of the transmission. However, the level of the presented model can still
be increased by including new influences. For example, including the moments of
inertia from the entire drive chain, it is also possible to cover the input speed character
or to include in-service shocks.
The results have not been validated by propriety experiment yet. Several technical
experiments are going to be performed to obtain corresponding data about vibrations
and transmission error. Real measured data are very useful for verification of computational model, because the results obtained from computational model are highly
dependent on the input parameters from the user.
Acknowledgements The research leading to these results has received funding from the project
FSI-S-17-4104 granted by specific university research of Brno University of Technology and
Project TH02010725 granted by Technology Agency of the Czech Republic. The authors gratefully
acknowledge this support.