Pistonless rotary engine
Encyclopedia
A pistonless rotary engine is an internal combustion engine
that does not use piston
s in the way a reciprocating engine
does, but instead uses one or more rotors, sometimes called rotary pistons. An example of a pistonless rotary engine is the Wankel engine
.
The term rotary combustion engine has been suggested as an alternative name for these engines to distinguish them from early (generally up to the early 1920s) aircraft engine
s and motorcycle engine
s also known as rotary engine
s. However, both continue to be called rotary engines and only the context determines which type is meant.
and rotational-speed-related mechanical stress
. the Wankel engine is the only successful pistonless rotary engine, but many similar concepts have been proposed and are under various stages of development. Examples of rotary engines include:
Production stage:
Development stage:
Conceptual stage:
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
that does not use piston
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...
s in the way a reciprocating engine
Reciprocating engine
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types...
does, but instead uses one or more rotors, sometimes called rotary pistons. An example of a pistonless rotary engine is the Wankel engine
Wankel engine
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
.
The term rotary combustion engine has been suggested as an alternative name for these engines to distinguish them from early (generally up to the early 1920s) aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
s and motorcycle engine
Motorcycle engine
A motorcycle engine is an engine that powers a motorcycle.Motorcycle engines may be two-stroke or four-stroke, reciprocating or Wankel, single-cylinder or multicylinder , or single-rotor or twin-rotor . The engine typically drives the rear wheel, but some small bikes such as the Velosolex have a...
s also known as rotary engine
Rotary engine
The rotary engine was an early type of internal-combustion engine, usually designed with an odd number of cylinders per row in a radial configuration, in which the crankshaft remained stationary and the entire cylinder block rotated around it...
s. However, both continue to be called rotary engines and only the context determines which type is meant.
Pistonless rotary engines
The basic concept of a (pistonless) rotary engine avoids the reciprocating motion of the piston with its inherent vibrationVibration
Vibration refers to mechanical oscillations about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.Vibration is occasionally "desirable"...
and rotational-speed-related mechanical stress
Stress (physics)
In continuum mechanics, stress is a measure of the internal forces acting within a deformable body. Quantitatively, it is a measure of the average force per unit area of a surface within the body on which internal forces act. These internal forces are a reaction to external forces applied on the body...
. the Wankel engine is the only successful pistonless rotary engine, but many similar concepts have been proposed and are under various stages of development. Examples of rotary engines include:
Production stage:
- The Wankel engineWankel engineThe Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
Development stage:
- The original Atkinson cycleAtkinson cycleThe Atkinson cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density, and is used in some modern hybrid electric applications.-Design:...
engine - The Engineair engine
- The LiquidpistonLiquidpistonThe LiquidPiston engine is a rotary engine, which operates on the High Efficiency Hybrid Cycle. This cycle consists of compressing air to a very high ratio, as is typical in the Diesel cycle. The air is then isolated in a constant volume chamber. Fuel is injected, and allowed to combust fully...
engine - The Sarich orbital engineOrbital engineThe Sarich orbital engine is a type of internal combustion engine, featuring rotary rather than reciprocating motion of its internal parts. It differs from the conceptually similar Wankel engine by using a shaped rotor that rolls around the interior of the engine, rather than having a trilobular...
- The QuasiturbineQuasiturbineThe Quasiturbine or Qurbine engine is a proposed pistonless rotary engine using a rhomboidal rotor whose sides are hinged at the vertices. The volume enclosed between the sides of the rotor and the rotor casing provide compression and expansion in a fashion similar to the more familiar Wankel...
- The Ramgen Integrated Supersonic Component Engine
- The Rand cam engineRand cam engineThe RadMax engine, also known as Ram-cam or Rand-cam engine is a pistonless rotary engine being developed by Reg/Regi Technologies Inc.- Design :...
- The RKM engine (RotationsKolbenMaschine)
- The Trochilic engine
- The Wave disk engineWave disk engineA wave disk engine is a type of pistonless rotary engine being developed at Michigan State University and Warsaw Institute of Technology. The engine has a spinning disk with curved blades. Once fuel and air enter the engine the rotation of the disk creates shockwaves that compress the mixture...
Conceptual stage:
- The GerotorGerotorA gerotor is a positive displacement pumping unit. The name gerotor is derived from "Generated Rotor". A gerotor unit consists of an inner and outer rotor. The inner rotor has N teeth, and the outer rotor has N+1 teeth. The inner rotor is located off-center and both rotors rotate...
engine