The automobile transmission is a set of speed changing devices used to coordinate the engine speed and the actual driving speed of the wheels, in order to exert the best performance of the engine. The transmission can produce different speed ratios between the engine and the wheels during the driving of the car. Then Xiaobian will introduce the working principle of automobile transmission in detail.
Manual transmission is called manual transmission (referred to as MT), also known as mechanical transmission, that is, the gear shifting lever (commonly known as “block”) must be turned by hand to change the gear meshing position in the transmission and change the transmission ratio to achieve the purpose of shifting.
How manual transmissions work
By shifting the gearshift lever, the driving gear on the intermediate shaft is switched, and the gear output of different sizes is combined with the power output shaft, thereby changing the torque and speed of the driving wheels.
The power input shaft of the engine is indirectly connected to the power output shaft through an intermediate shaft. As shown in the figure above, the two gears on the intermediate shaft (red) and the two gears on the power output shaft (blue) rotate with the engine output. But without the engagement of the synchronizer (purple), the two gears (blue) can only idle on the power output shaft (that is, it will not drive the output shaft to rotate). The synchronizer in the picture is in the middle state, which is equivalent to the transmission in neutral.
When the shift lever is moved to the left, the synchronizer is moved to the right to engage the gear (as shown in the figure above), and the engine power is transmitted to the power output shaft through the gear of the intermediate shaft.
The automatic transmission uses a planetary gear mechanism to change the speed. It can automatically change the speed according to the degree of the accelerator pedal and the speed of the vehicle. The driver only needs to manipulate the accelerator pedal to control the speed of the vehicle.
There are four common types of automotive automatic transmissions: hydraulic automatic transmission (AT), mechanical continuously variable automatic transmission (CVT), electronically controlled mechanical automatic transmission (AMT), and dual clutch automatic transmission (DCT) . At present, AT is widely used in cars, and AT has almost become synonymous with automatic transmission.
AT is composed of a hydraulic torque converter, a planetary gear and a hydraulic operating system. It achieves variable speed and torque through a combination of hydraulic transmission and gears. Among them, the hydraulic torque converter is the most important part of AT. It consists of pump wheels, turbines, and guide wheels, and has both the role of transmitting torque and clutch.
How AT automatic transmissions work
The hydraulic torque converter is the most characteristic part of AT. It directly inputs the engine power and transmits the torque. At the same time, it has a clutch function. The pump wheel will drive the turbine to rotate through the liquid, and then a guide wheel is added between the pump wheel and the turbine. The speed difference between the pump wheel and the turbine can be achieved by the reaction force. Because the torque converter has a wide range of automatic transmission torque conversion, a few rows of planetary gears are connected in series behind the turbine to improve efficiency. The hydraulic control system will automatically operate the planetary gears as the engine changes to achieve automatic transmission torque conversion.
Well, here is the working principle of the automobile transmission introduced by Xiaobian today. I don’t know if you have a deeper understanding of the working principle of the automobile transmission after listening to the introduction of Xiaobian? I hope the introduction of the editor will be helpful to everyone. If you want to know more information, please pay attention to the electric state, Xiaobian is waiting for you here!