Surfaces in contact and relative motion
Lubrication
Diagram of an engine using pressurized lubrication
Wikimedia Commons has media related to Internal combustion piston engine lubrication systems.
Surfaces in contact and relative motion to other surfaces require lubrication to reduce wear, noise and increase efficiency by reducing the power wasting in overcoming friction, or to make the mechanism work at all. At the very least, an engine requires lubrication in the following parts:
Between pistons and cylinders
Small bearings
Big end bearings
Main bearings
Valve gear (The following elements may not be present):
Tappets
Rocker arms
Pushrods
Timing chain or gears. Toothed belts do not require lubrication.
Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine
Why is the use of public transport is important especially in big cities?
In particular, many major urban centers there is more and more a problem with the huge traffic jams, especially during rush hours, which is why the authorities of many cities persuade motorists to give up to move your own vehicle and elected public means of transport. Although using public transport for sure we are exposed to the crowd on trams or buses, it should be induced to such exchange. True, motoring fans argue that the use of own car is much more comfortable, but we must bear in mind also that choosing the bus instead of the car contribute to fewer exhaust emissions.
Classification
Classification
There are several possible ways to classify internal combustion engines.
Reciprocating:
By number of strokes
Two-stroke engine
Clerk Cycle 1879 6
Day Cycle
Four-stroke engine (Otto cycle)
Six-stroke engine
By type of ignition
Compression-ignition engine
Spark-ignition engine (commonly found as gasoline engines)
By mechanical/thermodynamical cycle (these 2 cycles do not encompass all reciprocating engines, and are infrequently used):
Atkinson cycle
Miller cycle
Rotary:
Wankel engine
Continuous combustion:
Gas turbine
Jet engine
Rocket engine
Ramjet
The following jet engine types are also gas turbines types:
Turbojet
Turbofan
Turboprop
Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine