spur-type planetary gear

例句：

1. 1. The new car has a sprocket that makes it easy to change the tire.
   这款新车有一个星型行星齿轮，使更换轮胎变得容易。
2. 2. The train uses a sprocket to turn its wheels.
   火车使用星型行星齿轮来转动轮子。
3. 3. The gearbox is made up of several sprockets and gears.
   变速箱由几个星型行星齿轮和齿轮组成。