hollow coil

例句：

1. 1. The hollow coil is used to store energy in a compact form.
   空心线圈用于以紧凑的形式储存能量。
2. 2. The hollow coil is essential for the operation of the generator.
   空心线圈对于发电机的运行至关重要。
3. 3.The hollow coil was designed to reduce vibration and noise during operation.
   空心线圈被设计成在操作过程中减少振动和噪音。