Then there's increasing the number of rotor blades. This helps because each additional blade carries less of the weight of the helicopter, and thus produces less noise.
增加旋翼桨叶数量也是一种方法，这使得每片桨叶负载的直升机重量降低了，因此产生的噪音更小。
2
The unbalanced centrifugal force can cause vibration, noise and bearing wear of the rotor bearing, so that it can seriously affect the performance and life of the product.
这种不平衡离心力作用在转子轴承上会引起振动，产生噪声和加速轴承磨损，以致严重影响产品的性能和寿命。
3
This unbalanced centrifugal force on the rotor bearing will cause vibration, noise and accelerate the bearing wear, which seriously affect the performance and life of the product.