2nd ICAI 2022

International Conference on Automotive Industry 2022

Mladá Boleslav, Czech Republic

Figure 15: Effect of the number of needles in a bearing of the same dimensions on the contact pattern

Source: Škoda Auto, a.s., internal materials

Figure 16: Effect of the needle length of a bearing of different dimensions on the contact pattern

Source: Škoda Auto, a.s., internal materials

4. Conclusion This article summarized several design influences that directly affect the gear tooth contact pattern, either one path or total contact patterns. The analysis of these influences was performed using two methods. The assessment of the contact pattern was carried out using an experimental method that utilizes the imprint of the teeth by abrasion of the gear marking compound coating applied on the both tooth flanks. Simultaneously, simulation calculations were performed using MBS, which can be advantageously used in future gearing designs if sufficiently verified by experiment. The research confirmed that the clearances in the needle bearings on which the change gears are mounted affect the size of the gear tooth contact pattern. Also, the number and size of the needles of these bearings contribute to changes in the size of these contact patterns. The contact pattern is also affected by the fit clearances in the shaft supports on which the change gear is mounted. The last element that has been investigated is the sliding sleeve, which also contributes to changes in the size of the contact pattern. This research is only seemingly unrelated to the effect of gearing strength or gearing acoustics. In fact, the change in the contact pattern affects the pressure distribution and thus the strength and life of the gearing. Similarly, a change in the contact pattern also affects the excitation of vibrations during tooth engagement and therefore the noise level of the gearbox. The research findings show that the influence of all substructures and their precision on the gear meshing ratios should always be considered and examined when designing or changing the design of any gear transmission.

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