Dec 17, 2020 23:00:00

Introducing a next-generation rotary engine that can reduce the size of a small generator to one-fifth

A portable generator equipped with a next-generation rotary engine developed by

Liquid Piston , an engine development company based in Connecticut, USA, succeeded in reducing the size to one-fifth the size of the current portable generator, and the U.S. Army Won the small and medium enterprise technological innovation system.

LiquidPiston Announces Small Tactical Power Generator Development for US Army | Business Wire
https://www.businesswire.com/news/home/20201215005194/en/LiquidPiston-Announces-Small-Tactical-Power-Generator-Development-for-US-Army

LiquidPiston's 'inside-out' rotary X-Engine wins Army research contract
https://newatlas.com/military/liquidpiston-rotary-x-engine-army-generator/

Below is a movie explaining the structure of Liquid Piston's next-generation rotary engine 'X Engine'.

LiquidPiston X-Mini 79cc SI engine animation 1 --YouTube


The X Engine is in a triangular housing that looks like a rice ball with rounded corners ...

An engine that obtains power by revolving an eyebrows-shaped rotor. Since the

housing of a conventional rotary engine is eyebrows and the rotor is triangular , the structure is similar to that of the housing and rotor.

When driving, air (blue) is sucked into the corner space ...

The eyebrows-shaped rotor in the center revolves to compress the air.

Combustion is performed at the timing when the corner space is minimized to expand the air, and the pressure is used to obtain power.

In addition, the exhaust port is connected to the side of each corner.

The three corners of the housing (pink, purple, and green) each function as a

combustion chamber . High compression drive is also possible by adjusting the size of the rounded corners and changing the size of the combustion chamber.

Alec Schkolnik, co-founder and CEO of Liquid Piston, said that the X Engine is like a combination of the high compression ratio of a diesel engine, direct injection, the constant combustion cycle of an Otto cycle engine, and the high expansion ratio of an Atkinson cycle engine. It is possible to improve the lubrication and sealing problems, which were the weak points of conventional rotary engines, and to bring out powerful size-independent power and high efficiency.

The Liquid Piston is the size of a small generator that powers the digital fire control system of the

M777 155mm howitzer , the size of a gaming PC with a weight of 41 pounds and a capacity of 1.5 cubic feet (28.3 liters) by the X Engine. We succeeded in significantly reducing the size by 80% in weight and 70% in volume compared to the conventional product, and won the SME technological innovation system contract for the 2-5kW small tactical generator of the US Army. The actual small generator in question is below.

It looks like this when placed in front of the M777 155mm howitzer.

Regarding the question that 'X Engine will also be used for automobile engines,' Schkolnik stated, 'We will definitely target the automobile industry in the future.' 'Taking GM as an example, even the development of a new engine based on known technology requires development costs equivalent to hundreds of millions of dollars (about tens of billions of yen). X Engine has thermodynamic cycles, architecture, etc. It's a completely redesigned engine, so I wouldn't dare to develop it for the automotive industry at first, but would like to enter the automotive industry after demonstrating performance with niche applications, 'he explained.

In 2021, Liquid Piston will also focus on verifying the durability of the X Engine, as it has been making only prototypes for demonstration purposes to prove its technical benefits. Schkolnik said, 'It's been revealed that the X Engine works well, so I'd like to find out how many hours it will run. I've done tens to tens of hours of endurance testing, but hundreds of hours of endurance The test is about to begin, 'he said, and plans to conduct endurance tests on 5 to 10 prototypes.