What is the torque ratio of a torque converter?
2 Answers
The torque ratio of a torque converter is approximately 1.5 to 2.0, and it varies with operating conditions. A torque converter is a hydraulic component consisting of a pump impeller, turbine, and stator, installed between the engine and transmission. The functions of a torque converter include: 1. Transmitting rotational speed and torque; 2. Providing a non-rigid connection between the engine and automatic transmission, facilitating automatic gear shifting. Characteristics of a torque converter: 1. Excellent self-adaptability: Depending on the machine's driving resistance or other operational resistance, the torque converter can automatically and continuously vary speed and torque within a certain range; 2. Enhances machine lifespan: The working medium of a torque converter is liquid, which has a damping effect, reducing dynamic loads generated in the transmission system; 3. Improves machine performance: Hydraulically driven machines exhibit better stable low-speed performance, increasing the machine's traction with the ground.
I remember when I first learned to drive, starting an automatic transmission car was incredibly smooth. Later, I found out it was the torque converter amplifying the engine's torque, with a torque ratio typically between 1.7 and 2.5. This means the torque can be nearly doubled at startup, helping the car climb hills or accelerate effortlessly. For regular sedans, it's usually around 1.8 to 2.2, while SUVs, being heavier, might have a slightly higher ratio. Like my old car, after repairs, it stabilized around 2.0. The key is that it reduces the engine's burden, making driving less strenuous. However, if the fluid is too dirty or internal parts are worn, the ratio can drop below 1.5, causing jerky starts. That's why I've developed the habit of regularly changing the transmission fluid and checking the torque converter's condition during maintenance to prevent major issues.
