What is a Retarder?
2 Answers
The automotive retarder refers to a device that, when activated during deceleration or long downhill driving, allows the vehicle to slow down smoothly, avoiding the wear and heat generated by frequent use of the brakes. Below is a detailed introduction to the retarder: 1. Based on different working principles, automotive retarders can be classified into several typical structural forms, including engine retarders, hydraulic retarders, electric turbo retarders, motor retarders, and aerodynamic retarders. 2. Depending on the form of braking torque application, automotive retarders can be divided into primary retarders (those acting on the front end of the transmission) and secondary retarders (those acting on the rear end of the transmission). 3. When a vehicle is descending a long slope, using exhaust braking can achieve good braking effects. However, for heavy-duty mining dump trucks, the effectiveness of exhaust braking is limited, and it can cause some degree of damage to the engine. Therefore, mining dump trucks equipped with hydraulic-mechanical transmissions are also fitted with hydraulic retarders.
After driving for so many years, I believe the retarder is a life-saving device for heavy vehicles. Simply put, it's an auxiliary braking system installed on the gearbox or drive shaft. When we drive trucks on mountain roads and face a continuous 10-kilometer downhill, relying solely on foot braking would have already caused the brakes to overheat and smoke, potentially leading to brake failure. At this point, activating the retarder lever makes the vehicle feel like it's being pulled by magnetic force, steadily controlling the speed without even touching the brake pedal. Its principle is to generate resistance using hydraulic or electromagnetic force, converting the rotational energy of the wheels into heat and dissipating it. Newer models now even come with intelligent control systems that automatically calculate the slope and adjust the braking force. I recommend truck drivers who frequently travel in mountainous areas to opt for this feature—it doubles the safety factor.
