What is the principle of a retarder?
2 Answers
The principle of a retarder is to energize the excitation coil of the stator assembly through a control circuit, generating a magnetic field. The rotor assembly rotates at high speed along with the vehicle's transmission parts, cutting the magnetic lines of force and producing a reverse torque to decelerate the vehicle. Retarders are classified into first-level retarders and second-level retarders based on torque. A retarder consists of a rotor, stator, working chamber, input shaft, heat exchanger, oil storage tank, and housing. The method of using a retarder is as follows: when the vehicle is ignited, the retarder is in standby mode. When the vehicle needs to decelerate, pulling the manual control switch handle step by step to the desired gear can achieve the deceleration purpose. To turn off the retarder function, simply pull the manual control switch handle back to the 0 position.
I've been driving long-haul trucks for nearly a decade, and the retarder is an incredibly practical little helper. Its working principle mainly involves controlling speed through the engine exhaust valve. When you release the accelerator to decelerate, the retarder partially closes the exhaust valve, trapping some gas in the exhaust pipe, which increases exhaust resistance. This makes the engine do more compression work internally, like adding extra burden to itself, naturally slowing the vehicle down. This gadget saves the trouble of frequent braking and is particularly effective on long downhill sections, effectively preventing brake overheating failure. It also saves some fuel by utilizing the engine's energy recovery. I remember once on a mountain descent, I relied entirely on the retarder to control speed gradually, keeping the brake pads cool. Daily maintenance is simple too, just regular checks of the exhaust system. For safety, it's important to note that it's not the main brake, only for assistance, and you still need to be ready to brake at any time.
