(1) The influence of complex optimization modification scheme of large gear with long tooth profile and tooth crest involute+tooth direction drum on the time-varying meshing force of helical gear
The optimization scheme of the complex modification of the large gear with long tooth profile and tooth crest involute+tooth direction drum is the modification amount of the driving gear 0 μ M. The modification amount of the long tooth profile of the driven gear is 3 μ m。 Figure 1 shows the time varying meshing force curve before and after the helical gear pair is modified by the large gear long tooth profile tooth top involute+tooth direction drum compound at different speeds. Obviously, the modification effect of this scheme is not good, which not only increases the peak value of time-varying meshing force of helical gears under low speed, medium speed and high speed conditions to 20306.797N, 61036.934N and 105683.086N respectively, but also makes the meshing impact more serious.
(2) The influence of the compound optimization modification scheme of the long tooth profile of the large gear tooth crest arc+tooth direction drum on the time-varying meshing force of the helical gear
The optimization scheme of the compound modification of the long tooth profile of the big gear with the addendum arc and the tooth direction drum is the modification amount of the driving gear 0 μ M. The modification amount of the long tooth profile of the driven gear is 3 μ m。 Figure 2 shows the time varying meshing force curve before and after the helical gear pair is modified by the large gear long tooth profile and tooth crest arc+tooth direction drum compound at different speeds. It can be seen from the figure that the modification scheme is not ideal from the perspective of reducing the time-varying meshing force. The peak value of the time-varying meshing force of the helical gear under low, medium and high speed conditions is 20000.129N, 52758.305N and 100341.289N respectively.
(3) The influence of the compound optimization modification scheme of the long tooth profile of the large gear tooth crest broken arc+tooth direction drum on the time-varying meshing force of the helical gear
The optimization scheme for the compound modification of the long tooth profile of the large gear with the tooth crest broken arc and the tooth direction drum is the modification amount of the driving gear 0 μ M. The modification amount of the long tooth profile of the driven gear is 3 μ m。 Figure 3 shows the time varying meshing force curve before and after the helical gear pair is modified by the large gear long tooth profile tooth top broken arc+tooth direction drum compound at different speeds. It can be seen from the figure that although the time-varying meshing force of the helical gear pair after the optimization and modification of the scheme has decreased, and the peak meshing force under the low speed, medium speed and high speed conditions are 19988.063N, 52742.453N and 100395.117N respectively, which are decreased by 11.05N, 51.824N and 89.203N respectively compared with the unmodified ones, the curve is too tortuous, which is not conducive to alleviating the meshing impact between the helical gear pairs.
(4) Influence of compound optimization modification of large gears on time-varying meshing stiffness of helical gears
Figure 4 shows the time-varying meshing stiffness curve of the helical gear pair before and after the complex optimization modification of the large gear. Although the complex optimization modification schemes for the driven gear (large gear) are different, it can be seen that the time-varying meshing stiffness of the modified helical gear is significantly reduced, and its fluctuation range is 4 × 10^8N/m~5.03 × 10 ^ 8N/m, with a decrease of 1.3%.
To sum up, only the compound optimization modification of the large gear of the helical gear pair can only slightly reduce the stiffness excitation, but can not effectively improve the meshing impact between the helical gear pairs, and the cost of adding a tooth profile or tooth direction modification process in engineering practice is often extremely expensive. Therefore, on the premise that the optimization scheme of single modification method can meet the use requirements of helical gears, it is generally not recommended that the tooth profile and tooth direction compound modification, and all the compound optimization modification schemes are omitted here.