Pitch diameter (d) is the diameter of the pitch circle.

节圆直径(D)：节圆直径是节圆所在圆的直径。

Pitch Point is the intersection of the spline tooth profile with the pitch circle.

节点是键齿的齿廓与节圆的交点。

Particularly suitable for fixture building by direct mounting on cylinder head small pitch circle dia.

and accurate centring特别适合夹具直接安装在气缸盖(小分度圆直径。)

Pitch circle is the reference circle from which all transverse spline tooth dimensions are constructed.

节圆是一个参考圆，花键的键齿的所有的横向尺寸都是以节圆为基础开始计算的。

Gears on nonparallel, non-intersecting shafts also have pitch circles, but the rolling-pitch-circle concept is not valid.

非平行的齿轮，非交叉传动的轴也有节点，但不存在纯滚动节圆的概念。