There are many reasons for the formation of gear noise of electric rolling shutter, especially in the operation of high load and high speed, noise and vibration are always urgent problems to be overcome. The main points and Countermeasures of noise reduction are listed below. If we pay more attention to the noise problems according to the instructions, it can be greatly improved.

(1) 正确之齿面接触

(1) Correct tooth contact

实施齿面鼓形加工(Crowning)或削端加工(Relieving)避免单片接触，噪音自然会降低。适当之齿形修整对降低噪音也有效。齿面上之碰伤或打痕。

If crowning or relieving is implemented to prevent single chip contact, the noise will be reduced naturally. Proper tooth profile modification is also effective to reduce noise. Eliminate the bumps or marks on the tooth surface.

(2) 接纳平滑之齿面

(2) Smooth tooth surface

研摩，擦磨(Lapping)，砥磨(Honing)均可抵达很理想齿面粗度，另在油中热身运转一段时间也可以改善齿面粗度，这对噪音均有降低作用。

Grinding, lapping and honing can achieve ideal tooth surface roughness. In addition, warm-up operation in oil for a period of time can also improve tooth surface roughness, which can reduce noise.

(3) 选用良好精度之齿轮

(3) Select gears with good accuracy

将节距误差，齿形误差，齿沟偏差，齿筋误差改小，则噪音自然会变小。研磨齿面，除可改善齿轮及各个精度外，还可改良齿面粗度。故对减低噪音有很好之效果。

If pitch error, tooth profile error, tooth groove error and tooth rib error are reduced, the noise will be reduced naturally. Grinding tooth surface can not only improve the accuracy of gear and gear, but also improve the tooth surface roughness. Therefore, it has a good effect on reducing noise.

(4) 较大的咬合率

(4) Larger occlusal rate

咬合率越大噪音越小，因此减小压力角或加高齿深均可以增加咬合率。重叠率加大也可以降低噪音，因此螺旋齿轮比正齿轮噪音小。

Therefore, reducing the pressure angle or increasing the tooth depth can increase the bite rate. The increase of overlap ratio can also reduce the noise, so the noise of helical gear is less than that of spur gear.

(5) 适当之齿隙

(5) Proper backlash

若为脉动性之转动，则较小之齿隙对噪音之降低有资助。一般较均衡性之负荷，齿隙略大对噪音之降低有利。

In case of pulsating rotation, the smaller backlash is helpful to reduce the noise. Generally, the larger the backlash is, the better the noise reduction.

(6) 低速运转及低负荷

(6) Low speed operation and low load

齿轮之转数尽量压低，负荷尽量减轻可减少噪音。有用降低齿轮传动噪声的步伐。

The number of revolutions of the gear should be kept as low as possible, and the load should be reduced as much as possible to reduce the noise. It is useful to reduce the noise of gear transmission.

(7) 适当之润滑

(7) Proper lubrication

实施充分之润滑，粘度高的润滑油噪音较低。

The implementation of adequate lubrication, high viscosity lubricating oil noise is low.

(8) 接纳振动减衰率高之材质

(8) The material with high vibration attenuation rate is adopted

若为轻负荷低回转之齿轮，接纳塑胶齿轮是很好的选择，但要注意温度上升问题。铸铁齿轮比钢齿轮对降低噪音有效。

Plastic gear is a good choice for low rotation gear with light load, but pay attention to temperature rise. Cast iron gear is more effective than steel gear in reducing noise.