Motor rotativo Wankel

The main feature of this type of engine in front of one common such as a gasoline engine or a four-stroke diesel is the movement in performing the work. While these do so through a reciprocating linear movement is transformed to a rotation with a connecting rod-crank, The Wankel engine produces a rotational movement about its triangular piston directly, which rotates within a housing without there any alternative.

This motor car in the world is used for example by the brand Mazda RX-8 model .Its main advantages are the smooth operation (low vibrations and very uniform par), reduced weight, high specific power, a large number of revolutions and mechanical simplicity because it uses very few moving parts.

While it is difficult to recommend because it has a large consumption at partial loads and their segments have trouble getting a good seal (Oil consumption) and duration.


El rotary motor, has a simple constitution:

  • Block the housing: It is made of light alloy and is located inside the shirt, forming the friction surface with the rotor.
  • Intake and exhaust: Are located on the housing, radially and through which gas exchange takes place. The spark plugs are located on the opposite side to the ports.
  • Rotor: Has a triangular shape and each of its sides the combustion chamber is performed whose function is the same as any reciprocating engine.

In the center of the rotor there is a hole with internal teeth on one side meshing with a pinion which remains fixed on the side of the housing. This gear is used to support the rotor to maintain wobble inside the shirt. (Inside this bore the drive shaft is positioned).

The cooling and lubrication, are similar to any ordinary engine. You only need to note that given the difficulties of the rotor to dissipate the heat of the coolant, this is cooled by the oil. Also to prevent the oil overheating lubrication circuit is provided with a heat exchanger with a thermostat which regulates the passage. Lubrication of the segments is performed by adding oil to the fuel. (Amount regulates a device depending on rpm and engine load)


It belongs to the internal combustion engine operates on the four-stroke cycle. The rotation movement is obtained directly on the piston (also called rotor) that is triangular in shape and rotates driven by combustion occurs successively in three radial chambers.

The processes of intake and exhaust ports are made using (as the two-stroke engines) which are controlled by the rotation of the motor (It therefore needs no distribution).

Triangular rotor rotates on an eccentric located on the drive shaft. During its rotation, the three vertices of the rotor are in permanent contact with the inner surface of the jacket.

The internal teeth of a pinion meshing motor describing orbits around the. The rotation of the rotor is transmitted to the drive shaft through eccentric, so that for each revolution of the rotor of the drive shaft rotates three turn (internal toothed describes three orbits around the stationary gear) or put another way when the rotor moves 120, drive shaft or output shaft rotated through 360 °. For example when the engine reaches a regime 3000 rotor rpm and only runs in 1000 rpm. (Par smoother engine and more time for the exchange of gases.)

Mazda RX-8

In each of the three chambers formed between the rotor and the casing holding a four stroke cycle around the rotor, namely, three complete cycles per revolution, this means that each rotor 120 gets a boost (360º in the drive shaft)

In the rotary motor rotates the drive shaft 1080 ° (three times) to complete a cycle in each of the three chambers, at this time the rotor turns 360 (a return). However, in the reciprocating piston engine a complete cycle is performed every 720 ° (two turns) crankshaft rotation.

1No Admission: The admission of the air-fuel mixture begins when the vertex A discovers the inlet port, the displacement of the rotor progressively increases the volume of the chamber will fill with fresh air, until the vertex C closes the port.

2º Compression: The mixture is admitted into the chamber enclosed side AC, now producing its volume decreases the compression of the gases, Before reaching the maximum compression, with some progress, ignition occurs by hopping of the spark plugs or, initiating combustion.

3No Explosion: The pressure increase produced by combustion, drives the rotor while the gas expansion is performed, extending until the vertex A opens the exhaust port

4No Escape: Once discovered the exhaust port, burned gases are expelled at high speed due to the residual pressure of the expansion. The rotation of the rotor decreases the volume of the chamber to complete the process when the point C exceeds the exhaust port. The efficiency of gas exchange is dependent on the position of the ports.

Perhaps the explanation of this type of engine is somewhat difficult to understand, but it is also difficult to explain, since there is a lot of information and I've never seen your particular operating.

A movement of the engine with reciprocating piston (the most used either longitudinal, transversal and "V" o "W") and rotary (Shaky), There is another called Boxer opposed piston or much used brand Porch (the name of one of its models is given by the). Of the three is the least used.

Celso García.

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