Mazda Brought Back The Rotary Engine!

Опубликовано 17 февраля 2023, 15:00

The Wankel Rotary Engine Is Back In Production Thanks To Mazda!
How Rotary Engines Work - youtu.be/Ny4-Jc_qW60
Subscribe to Engineering Explained for more videos! - goo.gl/VZstk7
Recommended Books & Car Products - amzn.to/2BrekJm
EE Shirts! - bit.ly/2BHsiuo

From Mazda:
"With the discontinuation of the RX-8, Mazda ended mass-production of the rotary engine in June 2012. Today, some 10 years later, the rotary engine is making a comeback. This new rotary engine has been adapted to meet the needs of our times and is now being used to generate power rather than as a drive unit.

While the 13B Renesis engine used on the RX-8 was a 654 cm3 two-rotor engine, the MX-30 e-Skyactiv R-EV uses an 830 cm3 single rotor format for the rotary engine generator. With a 120 mm generating radius (R) and 76 mm rotor width, its compact size enables coaxial placement and integration with the electric motor, decelerator and generator to achieve a unit with an overall width of less than 840 mm that fits on the same body frame as the MX-30 BEV. We also successfully reduced the weight of the engine by over 15 kg by using aluminium for the side housing section of the engine structure instead of the iron used on the Renesis engine.

The main contributor to increasing fuel economy and reducing emissions on the MX-30 e-Skyactiv R-EV rotary engine was the use of direct fuel injection. When fuel is injected into the ports on a conventional rotary engine, a lot of the air-fuel mixture ends up at the back of the combustion chamber, not fully combusting and eventually being expelled as unburned gas. This has a negative effect on both fuel economy and engine output.

The rotary engine on the MX-30 e-Skyactiv R-EV uses direct fuel injection, making it possible to distribute the air-fuel mixture to the main combustion area and achieve more efficient combustion. Additionally, direct fuel injection atomises the fuel at the time of injection making it possible to sufficiently vaporise fuel even at lower temperatures. This also helps prevent the injection of excess fuel.

The engine also adopts an exhaust gas recirculation (EGR) system to improve fuel efficiency. Adding an EGR system that operates mostly at low rpm and low loads improves fuel economy by preventing cooling loss caused by rotary engine combustion chambers having a greater surface area than those of a reciprocating engine.

Apex seals are attached to the tip of each rotor to ensure the combustion chambers are airtight. For the MX-30 e-Skyactiv R-EV, we increased the width of these seals to 2.5 mm to improve wear resistance. We also changed the plating on the trochoid surface inside the housing to reduce wear and frictional resistance. For the sides of the housing, we use aluminium for the surface of the side housing and have added high velocity oxygen fuel coating to add a ceramic coating which also reduces wear and frictional resistance."

Related Videos:
Why The Rotary Engine Died - youtu.be/v3uGJGzUYCI
Mazda's Hydrogen Rotary Engine - youtu.be/U-n5L0cXcpg

References:
MX-30 Press Kit - eu.mazda-press.com/forms/login...
RX-8 Press Kit - newsroom.mazda.com/en/cars/112...
BMW i3 Press Kit - bmwusanews.com/newsrelease.do?...
VVT Study - doi.org/10.1016/S0360-5442(02)...
Rotary Engine Intake Timing Study - doi.org/10.2298/TSCI180504058Z
Mazda Patent - patents.google.com/patent/US20...

Hat Tips:
Mazda VVT Patent - carbuzz.com/news/mazdas-new-ro...
MX-30 R-EV Background - greencarreports.com/news/11384...

Engineering Explained is a participant in the Amazon Influencer Program.

Don't forget to check out my other pages below!
Instagram: instagram.com/engineeringexpla...
Facebook: facebook.com/engineeringexplai...
Twitter: twitter.com/jasonfenske13
EE Extra: youtube.com/channel/UCsrY4q8xG...