axle concentration

例句：

1. 1. The axle concentration of the engine is critical for its performance.
   发动机的轴心浓度对其性能至关重要。
2. 2. The axle concentration of the gearbox is crucial for its efficiency.
   齿轮箱的轴心浓度对其效率至关重要。
3. 3. The axle concentration of the transmission is essential for smooth operation.
   传动轴的轴心浓度对于平稳运行至关重要。