Transmission function

It has three functions: changing transmission ratio, driving in the opposite direction, interrupting power transmission and realizing neutral position.

1, change the transmission ratio

By changing the transmission ratio, the speed of the car and the torque on the driving wheel of the car can be changed, so that the engine can work under the most favorable conditions.

When a car is running, its engine needs to work under different working conditions to meet the needs of the environment because of the different surrounding environment.

For example, when a car is driving on an expressway, the speed should be above 100 km/h, while when driving on urban roads, the speed is generally around 50 km/h; When the car is driving downhill, the resistance is quite small, when driving straight, the resistance is small, and when driving uphill, the resistance will increase greatly, and so on.

2. Drive in the opposite direction

In daily life, it is often necessary to reverse the car, but the crankshaft of the engine can only rotate in one direction. Then the question is coming, how to reverse the car? The great hero of this function is transmission. Because there is reverse gear in the gearbox, we can reverse it. ?

3. Interrupt power transmission and realize neutral position.

When the clutch is engaged, the gearbox does not output power, and when the clutch is not engaged, but in neutral, the gearbox can also output power. This function of the gearbox enables the driver to leave the driver's seat while the car is still moving. When the engine starts, the car shifts gears or stops, the transmission is also needed to interrupt the power transmission.

Transmission classification

1, according to the change of transmission ratio, the transmission is divided into three types: step type, stepless type and comprehensive type.

① Stepwise transmission: There are a variety of optional fixed transmission ratios, and gear transmission is adopted. It can also be divided into two types: ordinary gear transmission with fixed gear shaft and planetary gear transmission with partial gear (planetary gear) shaft rotating.

② Continuously variable transmission: the transmission ratio can be changed continuously within a certain range, such as hydraulic, mechanical and electric.

③ Integrated transmission: It is composed of a stepped transmission and a continuously variable transmission, and its transmission ratio can be continuously changed in several sections between the maximum and minimum values.

2. According to different control modes, the transmission can be divided into three types: forced control, automatic control and semi-automatic control.

① Forced operation of the transmission: the driver directly controls the shift lever to shift gears.

② Automatic control transmission: the selection of transmission ratio and gear shifting are automatic. The driver only needs to operate the accelerator pedal, and the transmission can control the actuator according to the load signal and vehicle speed signal of the engine, thus realizing gear shifting.

③ Semi-automatic control transmission: it can be divided into two categories: one is automatic shifting of some gears and manual (forced) shifting of some gears; The other is to select the gear through the button in advance, and when the clutch pedal is pressed or the accelerator pedal is released, the actuator shifts gears automatically.