negative displacement pump

例句：

1. 1.The negative displacement pump is used to control the flow of oil in the engine.
   负排量泵用于控制发动机中油的流动。
2. 2.The negative displacement pump is a crucial component in the fuel injection system.
   负排量泵是燃油喷射系统中的关键部件。
3. 3.The negative displacement pump is designed to provide precise control over the amount of oil being injected into the engine.
   负排量泵被设计用来精确控制注入发动机中的油量。