A form of gear used by Benz in which small pinions revolve around a central or sun gear and mesh with an outer ring gear called the annulus. Type used in the Ford Model T. Also called planetary gears, sun-and-planet gears.

The part of the air-conditioning system where refrigerant changes from a liquid to a gas and absorbs heat from the air.

The system of exhausting the burned gases from an internal-combustion engine consisting of piping or tubing, silencers, and, at times, resonators.

The network of passages that gathers the exhaust gases from the various exhaust ports and routes them toward the catalysts and mufflers of the exhaust system. Metal tubes that lead exhaust gases from the engine to the exhaust system. A manifold with free-flowing passages of a carefully designed configuration, called a 'header,' can improve breathing.

The passageway in the cylinder head leading from the exhaust valves to the exhaust manifold.

An exhaust-emission control system in which a portion of the exhaust gas is picked up from the exhaust manifold and sent back to the intake manifold to be reburned in the engine. Mixing exhaust gases with the fresh air/fuel mixture lowers the combustion temperature and reduces the formation of oxides of nitrogen in the exhaust. The EGR valve is part of the emissions control system; it recirculates exhaust gas into the intake manifold, cooling the combustion chamber.