tooth top

The transmission part is an involute gear, and the working part can adopt different working faces, such as a cylinder excircle face, a circular arc tooth or an involutes tooth gear top cavetto.

传动部分是渐开线齿轮，工作部分可采用不同的工作面，如圆柱外圆面或圆弧形齿或渐开线齿轮齿顶修圆。

The greater the an and h_ ( an)~, the more favorable to the contact ratio while the more unfavorable to the thickness of the tooth top;

a n，h（an）~愈大，对重合度愈有利，但对齿顶厚变化愈不利。

Make sure you brush the top, front and back surfaces of each tooth. Don't forget your back molars.

确保刷到每一颗牙齿的顶部和前后表面。不要忘记磨牙。

By this method one can obtain a higher contact ratio under conditions of no undercut and ensure thickness of tooth top, which is possible to be manufactured by the current machine tools and the standard cutters.

这种方法可以有效地增大端面重合度，并保证所设计的齿轮不根切、齿顶不变尖，可在现有机床上使用标准系列刀具加工。

The top front teeth are thewhich are at risk from tooth decay.

上门齿是最容易受到腐蚀的牙齿.