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) 正確之齒面接觸

(1) Correct tooth contact

實施齒面鼓形加工(Crowning)或削端加工(Relieving)防止單片接觸，噪音自然會降低。適當之齒形修整對降低噪音也有效。齒面上之碰傷或打痕。

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) 采用光滑之齒面

(2) Smooth tooth surface

研摩，擦磨(Lapping)，砥磨(Honing)均可達到很理想齒面粗度，另在油中熱身運轉一段時間也可以改善齒面粗度，這對噪音均有降低作用。

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) 選用良好精度之齒輪

(3) Select gears with good accuracy

將節距誤差，齒形誤差，齒溝偏差，齒筋誤差改小，則噪音自然會變小。研磨齒面，除可改善齒輪及各個精度外，還可改良齒面粗度。故對減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) 較大的咬合率

(4) Larger occlusal rate

咬合率越大噪音越小，因此減小壓力角或加高齒深均可以增加咬合率。重疊率加大也可以降低噪音，因此螺旋齒輪比正齒輪噪音小。

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) 適當之齒隙

(5) Proper backlash

若為脈動性之轉動，則較小之齒隙對噪音之降低有幫助。一般較均衡性之負荷，齒隙略大對噪音之降低有利。

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) 低速運轉及低負荷

(6) Low speed operation and low load

齒輪之轉數盡量壓低，負荷盡量減輕可減少噪音。有用降低齒輪傳動噪聲的措施。

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) 適當之潤滑

(7) Proper lubrication

實施充分之潤滑，粘度高的潤滑油噪音較低。

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

(8) 采用振動減衰率高之材質

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

若為輕負荷低回轉之齒輪，采用塑膠齒輪是很好的選擇，但要注意溫度上升問題。鑄鐵齒輪比鋼齒輪對降低噪音有效。

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.