What is the working principle of an AT automatic transmission?
2 Answers
AT automatic transmission works by assembling two turbine blades in a space filled with hydraulic oil, which are connected to the power input end and the output end respectively. The impeller at the power input end generates a strong vortex to drive the impeller at the output end, achieving power transmission. The core of the automatic transmission lies in achieving automatic gear shifting. Automatic gear shifting means that during the driving process, the driver presses the accelerator pedal as needed, and the automatic transmission can automatically shift into different gears based on the engine load and the vehicle's operating conditions. The advantages of AT include the use of clutch shifting, which enables uninterrupted power shifting and smooth gear changes. The use of a torque converter can buffer the engine's impact and vibration. Due to the use of a torque converter, the vehicle has good low-speed driving capability.
From my years of experience working with cars, I've learned that the working principle of AT automatic transmissions is quite fascinating. It primarily relies on the combined operation of a torque converter and planetary gear sets. The engine's power is first transmitted to the torque converter, which contains hydraulic fluid. The impeller and turbine agitate the fluid to transfer torque and eliminate shock. Subsequently, the planetary gear sets use multiple small gears to switch gear ratios like magic. The computer system reads vehicle speed, throttle position, and engine RPM to control the hydraulic shift valves, enabling smooth upshifts or downshifts. The entire process is seamless, ensuring a jerk-free driving experience. For maintenance, regular transmission fluid changes prevent sludge buildup that could clog the system, otherwise causing delayed shifting. AT eliminates clutch operation, making it particularly suitable for congested urban areas and providing a more worry-free driving experience. Modern versions also integrate sensors for intelligent optimization, improving response speed compared to older hydraulic-controlled models.
