在机床有级变速传动中,转速几乎无例外地采用等比数列。这一方面是因为等比数列可保持速度损失为常数,另一方面是便于通过串接传动组来实现。在单公比转速数列的基础上,又出现了中间密(转速数列小公比φ)两端疏(大公比φ~2)被称作多公比(或混合公比)的派生形式。这适应机床主轴两端转速 In the machine level variable speed drive, the speed is almost without exception, the use of geometric series. This is due in part to the fact that the geometric progression preserves the loss of speed as a constant and, on the other hand, facilitates the series transmission. On the basis of the number series of the male and the male, a derivative of the intermediate density (φ = 2) is called the multiple male ratio (or mixed ratio). This adapts to the speed of both ends of the machine tool spindle