Men operating a bicycle crankpump refuel cars at the site of a gas station in the earthquake- and tsunami-destroyed town of Minamisanriku, northeastern Japan. (AP Photo/David Guttenfelder)
日本东北部，被地震和海啸摧毁的南三陆町市。人们在一个加油站边运行一个脚踩曲轴泵给汽车加油。
2
On the basis of studying the chance error occurred in the manufacturing process of plunger pump, the writer puts forward the influence of mechanical error on the flow rate of the crank plunger pumps.
通过研究柱塞泵制造过程中的随机误差，明确提出了机械误差对曲柄柱塞泵流量的影响。
3
Drilling pump power end is a group of crank, link mechanism.