Rotary engine

The rotary engine is an innovative design of a combustion engine, primarily for cars and used most successfully by Mazda. It features fewer moving parts, a more compact and lighter structure, and greater horsepower than traditional piston engines.

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Using a central spinning part in the combustion cycle meant the rotary engine was lighter and more powerful than what piston engines could typically achieve at the time, and this made it ideal for sports cars. ... The drawbacks - like a lack of power lower in the rev range, and fuel economy that would make even a Land Rover Discovery look smug - didn’t matter so much, and so the engine made its debut in the Cosmo Sport in 1967. Producing 110bhp at 7,000rpm and completing a quarter-mile sprint in 16.4sec, the Cosmo topped out at 115mph, thus proving that rotary power was viable, competitive and desirable.

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The Mazda RX-8 was manufactured with a Wankel rotary engine for a half-century (including its predecessors) until it was discontinued in 2012. Mazda promises to produce a hybrid rotary engine car beginning in 2022.

Leftists oppose car innovations that enhance freedom, including the rotary engine.

Hybrid models

A new Japanese patent discloses using a rotary engine stars in hybrid cars.

In another development, "LiquidPiston ... invent[ed] a new optimized thermodynamic cycle and a rotary engine platform. A thermodynamic cycle determines how much of the energy contained in the fuel can be converted into useful work output, with the balance being wasted as heat."

Trends

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Wankel rotary engine (RE) is gaining acceptance with lower level of vibrations (González Espasandín et al. 2014). It is a four-stroke rotary combustion ICE, with vantages such as simple structure, multi-fuel, higher speed, high power density, low noise and low vibration (Chen et al. 2017; Yang et al. 2018a). A triangular-shaped rotor coupled to an eccentric shaft accomplishes a sinusoidal variation of volume in the rotor housing. This power section generates the output torque and drives the cooling and lubrication systems (Yewale et al. 2017). However, incomplete combustion, high fuel consumption and poor emissions are some issues. REs are more suitable in mobile electricity generators, hybrid vehicles and small aircraft. Over the past few years, the use of turbochargers, direct injection, and optimizing seals increased the performance of REs. Employing hydrogen fuel enrichment this technology achieved better combustion levels, lower CO emissions and controllable higher NOx emissions (Chen et al. 2017; Yang et al. 2018a).

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History

There are 17,786 patents mentioning "rotary engine," dating back to 1840.

Mazda began making cars with the rotary engine around 1960, and American manufacturers considered using rotary engines around that time too. Credit for the invention is often given to the German Felix Wankel, who supposedly obtain a patent earlier on his odd design in 1929 (not in the United States), but he did not build a prototype until 1957. Wankel had no engineering education.

21st century European Union changes in emission regulations hurt the sales of Wankel-based rotary engines there, which tend to have a bit more fuel in their exhaust.

Leftist opposition to the rotary engine

Leftists generally oppose all developments in energy, unless it results in government rationing as green energy does. Accordingly, Leftists opposed the rotary engine. The DailyKos admits that "[t]he engine was lightweight, compact, smooth, and had few moving parts," but then trashed it while comparing it to nuclear power.

Mazda rotary pickup

This car review praises a new pickup truck (RX-4) introduced by Mazda that used the rotary engine:

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[T]he Wankel engine needs high rotational speed by its very nature and it gives no sensation at all of being busy at any highway speed. Its internal parts aren't that busy anyway: the two rotors are turning at a third the speed of the output shaft. By the way, performance should be more than adequate with the optional automatic transmission; we've tried it in the RX-2 and found it quite satisfactory. But it would lower fuel economy.

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As to its quiet smoothness and speed:

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[T]he engine is reasonably quiet and, as usual, butter-smooth as it pulls strongly up through the gears or merely accelerates impressively in top gear. As with the passenger cars there's a warning buzzer to keep you from overdoing it, coming on at something over 6000 rpm. We used 7000 rpm as a limit and found the pickup capable of 0-60 mph in 11 sec flat and the quarter-mile in 18.3: not as quick as the fastest American pickup, but peppy indeed.

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See also

• Rotary engine cars