对于分度圆直径较大,不便采用公法线长度测量的齿轮,用测量分度圆处弦齿厚及测量齿高检测成品齿形是必要的。分度圆处弦齿厚及测量齿高的计算可用精确计算和近似计算两种方法。当螺旋角β=10～30°、齿数Ζ=10～30时,用近似法计算弦齿厚及测量齿高的最大误差为0.00001～0.001m_n,当齿数大于30时,误差更小,完全可以满足现场实际的需要。 For the larger diameter circle, inconvenience to use the length of the common law of the gear measurement, measuring the pitch circle with tooth thickness and tooth height measurement of finished tooth profile is necessary. Centimeter at the pitch tooth thick and tooth height calculation can be calculated using the exact calculation and approximate two methods. When the helix angle β = 10 ~ 30 ° and the number of teeth Z = 10 ~ 30, the maximum error of calculating the tooth thickness and measuring tooth height by the approximate method is 0.00001 ~ 0.001m_n. When the number of teeth is more than 30, the error is smaller, Meet the actual needs of the scene.