Which motors can use electric brake without friction (like big trucks electric brake systems)?
The type used on a big truck is called a compression brake, a.k.a. Jake Brake. It can be used in diesel engines. It takes advantage of the 4-stage cycle of the piston. Normally, the stages go like this: (1) Intake – Intake valves open, piston moves down and draws in air (and fuel, for a regular combustion engine) (2) Compression – Intake valves close, piston moves up and compresses the air. In a diesel engine, fuel is injected at the very end of this stage. (3) Power – In a regular combustion engine, a spark plug ignites the fuel. In a diesel engine, the heat from the compressed air causes it to ignite. Either way, the piston moves down, providing power to turn the engine. (4) Exhaust – Exhaust valves open, piston moves up and pushes out exhaust. Now imagine you take your foot off the gas, so that no fuel goes into the piston: At stage (2), the air is compressed. This takes a lot work for the engine to do. In stage (3), there’s no power from combustion, but the compressed air acts like
