*2.1. Determination of Gear Engagement Position*

In this paper, a pair of gears with the same parameters are selected for engagement. The basic size parameters of the gears are shown in Table 1. Through calculation, the coincidence degree of the engaged gear is 1.56 so there are engagemen<sup>t</sup> positions of a single pair of teeth in the entire engagemen<sup>t</sup> circle.


As it can be seen from the literature [18] and Figure 2, for ideal gears, when the engagemen<sup>t</sup> positions are single-pair tooth contact positions (positions 16–27), the single pair of teeth bears all the applied load, that is to say, for one period of tooth engagement, the maximum TSCS occurs in the positions 16–27. As such, this paper defines the engagemen<sup>t</sup> position of the TSCS analysis at the position of the gear pitch circle, and the TPD, ME and LCM of the tooth surface are input and adjusted based on this engagemen<sup>t</sup> position, so as to research and analyze the influence of different factors on the TSCS.

**Figure 2.** The load-sharing ratios of the ideal gears.
