摘要
介绍了一条新型螺旋线，该线有理论推导，可广泛应用于通风机、水泵壳体的型线设计上，有很高的实用价值．该螺旋线能够直接用仪器绘出，可以近似替代其它螺旋线．
A new type of helix,based on theories,was used in ventilator,water pump etc.It possess higher practical value.The helix was drawn directly in instruments and might substitute for other helixes.
关键词
螺距
变螺距函数
螺旋线
近似性
绘图仪
泵
壳体
Thread pitch,The helix with changed thread pitch function,Approximation,Drawing instrument
