测圆柱齿轮的齿厚常用四种办法:分度圆弦齿厚、固定弦齿厚、公法线长度以及用圆棒或钢球测量。公法线长度的测量最简单、可靠,现场有一把卡尺即可,但有些斜齿轮却不能用。因为测量螺旋齿轮的公法线长度必须在齿轮的法向截面,要求有足够的宽度,就是齿宽 b 应满足下列条件 b≥L sinβ否则卡尺脚将超出齿轮外面(图1),难以测量。 Cylinder gear tooth thickness measured commonly used four ways: indexing circular chord tooth thickness, fixed chord thickness, the length of the common law and with a round bar or ball measured. The measurement of the length of the common normal is the simplest and most reliable, with a caliper on the scene, but some helical gears can not be used. Because the normal length of the measuring helical gear must be normal to the gear section, a sufficient width is required for the tooth width b to satisfy the following conditions: b ≥ L sinβ; otherwise, the caliper foot will be outside the gear (Fig. 1) and difficult to measure.