车床、铣床和滚床的挂轮计算中,演算公式的最后分数或小数,要化成两个、四个或六个挂轮齿数。有时最后的分数(小数同样也要化成分数),分母或分子是较大的质数,不能分解;或者虽不是质数,但分解后不是机床所备有的挂轮齿数,遇到这些情况,就得求出近似分数,而这些近似分数是可以分解为适当大小的齿数的。这就要用挂轮近似计算法。挂轮近似计算法的 Lathe, milling machine and the roller bed in the calculation of the wheel, the formula last fraction or decimal, to be turned into two, four or six of the number of teeth on the. Sometimes the last fraction (decimals also have to be part of the composition), denominator or molecule is a larger prime number, can not be decomposed; or though not a prime number, but after the decomposition is not the number of gear teeth on the machine, in these circumstances, you have Approximate fractions are found, and these approximate fractions can be broken down into the appropriate number of teeth. This is about to use the approximate method of change. The approximate calculation of the law