It is believed that even those who have a slight understanding of mechanics can understand that the role of the transmission system is to transmit power to drive vehicles. However, this is only the fundamental role of the transmission system. In fact, the important role of transmission system is "speed change".

　　首先來看看什么是傳動系統。汽車靠驅動輪旋轉來行駛，但發起機并不直接驅動驅動輪。發起機的動力經由變速器、差動齒輪、傳動軸等傳給驅動輪。這整套設備稱作傳動系統(驅動系統或者動力傳輸系統)。

　　First, let's look at what a transmission system is. The car runs by rotating the driving wheel, but the engine does not drive the driving wheel directly. The power of the engine is transmitted to the driving wheel through the transmission, differential gear, transmission shaft, etc. This whole set of equipment is called a transmission system (drive system or power transmission system).

　　濟南自動變速箱維修

　　Maintenance of Jinan Automatic Transmission

　　什么傳動系統的重要作用是“變速”呢?舉例來說，記得騎著三輪車追不上自行車，而之所以會這樣，主要緣由是三輪車不如自行車的速度快。此外，小孩子即便會騎三輪車，蹬起來也不容易，而自行車的話，小孩子也能隨便蹬動。形成這種差別的緣由是變速功用。那為什么必需變速呢?簡單地說是由于假如傳動系統直接將發起機的轉動信息停止傳送的話，就沒有足夠的扭矩來驅動汽車行駛。因而，遭到發起機驅動力的傳動系統要減少轉動次數，增加扭矩，然后將之傳送到驅動輪。

　　What is the important role of the transmission system? For example, remember that riding a tricycle can not catch up with a bicycle, and the main reason for this is that the tricycle is not as fast as the bicycle. In addition, even if a child can ride a tricycle, it is not easy to pedal, and if the bicycle, the child can pedal freely. The reason for this difference is the variable speed function. So why do we have to change gears? Simply because if the transmission system stops transmitting the information of the engine's rotation directly, there will not be enough torque to drive the car. Therefore, the drive system driven by the initiator needs to reduce the number of rotations, increase the torque, and then transmit it to the driving wheel.

　　濟南自動變速箱維修廠家解說汽車從啟動到高速行駛期間，速度不時變化，道路也有緩有陡。條件發作變化，變速辦法也必需做出相應的調整，因而傳動系統必需可以在不同變速形式之間互相切換。如今你明白了嗎?假如傳動系統不能停止“變速”來增加扭矩，僅靠發起機產生的動力是缺乏以驅動車輛的。

　　Jinan automatic transmission maintenance manufacturer explained that during the period from start-up to high-speed driving, the speed changes from time to time, and the road is slow and steep. When conditions change, the method of transmission must be adjusted accordingly, so the transmission system must be able to switch between different forms of transmission. Now you see? If the transmission system can't stop "changing speed" to increase the torque, the power generated by the engine alone is lacking to drive the vehicle.