2·The most common rotary-pump designs used today are spur-gear, generated-rotary, sliding-vane, and screw pump, each type has advantages that make it the most suitable for a given application.
今天最常用的旋转泵是外齿轮泵、内齿轮泵、摆线转子泵、滑动叶片泵和螺旋泵。每种类型的泵都有优点，适合于特定场合的应用。
3·The pump having the Angle adjustable vane is called the variable pitch vane type, and having the non-adjustable vane is called the fixed vane type.
循环水泵可分为拥有叶片角度调节装置的可调叶片式，和叶片不可调节的固定叶片式。