basic crown gear

例句：

1. 1. The basic crown gear is responsible for the smooth operation of the machine.
   基本齿轮负责机器的平稳运行。
2. 2. The engineer designed a new type of basic crown gear to improve efficiency.
   工程师设计了一种新型的基本齿轮，以提高效率。
3. 3. The basic crown gear was made from high-quality steel, ensuring durability and longevity.
   基本齿轮由优质钢材制成，确保耐用性和持久性。