The pressure created by the combustion of the fuel drives the piston downward .

柴油燃烧生成的压力向下推动活塞。

It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates .

它的两端可转动，从而其角度可随着活塞的运动和曲轴的转动而改变。

To understand why , imagine trying to drive a piston using a container full of heated gas .

要理解这是为什么？设想一下，试着在装满加热气体的容器中来推动活塞。

He noted that in 2008 car production was disrupted when a supplier was unable to deliver piston rings .

他举例说，2008年一家供应商无法发送活塞环的时候，汽车生产就出现了中断。

As the piston nears the top of the cylinder , the cycle repeats with step 1 .

当活塞运行到最高位附近时，活塞按第一步运行，形成一转并且周而复始下去。