Theoretically the sum of the velocities of the three pistons on the discharge stroke in a low-fluctuation triplex pump should be a constant, and this can be achieved by means of the cam mechanism.

• 对于三缸低波动往复泵，理论上应使三个活塞在排出行程（吸入行程）中的速度之和为一常数，采用凸轮机构能达到这一目的。