TRIZ Case Study Paper:

New Motor and TRIZ Evaluation
Vratislav Perna (PERNA Motors, Czech Republic),
Bohuslav Bušov (Brno Univ. of Tech., Czech Rep.),
Pavel Jirman (Tech. Univ. of Liberec, Czech Rep.)
Presented at ETRIA World Conference 'TRIZ Future 2006' Held at Kortrijk, Belgium, on Oct. 9-11, 2006
[Japanese translation by Masahiro Saitoh and Toru Nakagawa, posted in the Japanese page on Aug. 17, 2007]
[Posted on Aug. 17, 2007]  Under the permission by the Author.   

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Editor's Note (Toru Nakagawa, Aug. 4, 2007) 

The paper posted here was originally presented last year at ETRIA TFC 2006 held at Kortrijk, Belgium. 

This is a report on an amazing invention/innovation and its evaluation with TRIZ.  In my 'Personal Report of ETRIA TFC 2006' posted in this Web site in English, I reviewed this paper in detail.  The part of my review is cited below.

[TN (Aug. 17, 2007):  In my Japanese page I wrote some more introduction to the readers, but I am going to postpone translating it into English and to post this and two other articles without any further delay.]

Introduction & Review of the Presentation (Toru Nakagawa (OGU), Dec. 31, 2006)

Excerpt from Nakagawa's 'Personal Report of ETRIA TFC 2006' (posted on Jan. 7, 2007)

Vratislav Perna (PERNA Motors, Czech Republic), Bohuslav Busov (The Brno University of Technology, Czech Republic), and Pavel Jirman (The Technical University of Liberec, Czech Republic) [46] gave an amazing presentation with the title of "New Motor and TRIZ Evaluation".  This is an introduction to a novel motor, which may be difficult for readers to imagine without seeing animated models, and the evaluation and extension of the idea from the TRIZ views.  The motor is a whole family of 'a set of nonlinear screws' having the functions of air (or any gas or liquid) compression and expansion.  The invention was patented as US Patent 20030012675 A1.  Anyway, look at the schematic arrangement of the new motor in the figure below, and then read the Abstract written by the Inventor (the top Author) and the TRIZ experts (the second and third Authors):   


The article presents use of TRIZ methodology for understanding and evaluation of significant invention.  New solution of a motor presented in the article -- based on invention of the nonlinear rotating screw mechanism -- can be characterized from a TRIZ point of view:
  - as an interesting combination of preferences and partial elimination of weak points of the two alternative systems (piston motor and a gas turbine),
  - as a combination of the system and the anti-system (compressor and expander),
  - as a system, bi-system and poly-system (motor with one, two, three, or more shafts),
  - as a case of total nonlinearity of shapes (lines, surfaces, spaces)
  - as a case of trimming (of classical combustion engine),
  - as a case of radical innovations, etc.
Generally, the new motor is a complex invention with numerous variable applications and a good case of increasing ideality of the system. For example the propeller is one of the possible applications of the base invention -- the screw mechanism. This could also be a challenge for students and teachers to observe and study use of TRIZ tools in one specific invention.

The principle of the new motor is illustrated in the figures below.  Suction with compression is performed in the left part of the motor, ignition in the middle, and expansion with exhaust in the right part.

Volume (solid curve) and pressure (broken curve) change along the course.  Air is suctioned and compressed in the left part, and then ignited with the fuel introduced in the middle part, causing the sudden rise in pressure which turns the screw while expanding and being exhausted.

Course of proportions.  The two screws rotate in the counter directions with each other. 
[Refer to the pictures below for the image of actual shape of the 'nonlinear pitch screws'.]

Side face forms. 

As shown in the middle figure, the fuel gas is introduced into the middle part from the side pipe and ignited continuously; thus resulting no much periodic change in the operation. 

This invention can have tremendous fields of applications, including motors (with parallel axes, with convergent or off-tracking axes of rotors, with multiple peripheral axes, etc.), screw-shaped compressors, ventilator fans, vacuum pumps, pumps, marine drive (propellers), etc. 

As a simpler application of the present invention, a model of propellers were designed and tested with good performance.  The following five figures show respectively one of the spiral shafts, schematic top view, picture of assembled screws, picture of a prototype propeller from front side, and the prototype propeller installed on the free-rotatable vertical shaft with an engine on the top and a rudder. 



This propeller demonstrated a very high ability of navigating a boat by virtue of its propelling direction of 360 degrees and its smooth power change.  The fact that the rotors are completely covered with a "stator" produces much safety and also efficiency performance.  The propeller shown above is designed to have the acceleration ratio of 1:3 between the input and output velocities of the media and the pumping volume of 2 liters per one revolution of the rotor.  Thus, in 300 revs per minute, it is possible to have outflow of the media more than 600 liter/min at the velocity of approx. 140 km/h, the Authors write.  This propeller, with counter rotating screws, also has the advantage of eliminating undesirable careenage characteristic for classic screw propellers.  The Authors also write: "The new propeller could be realized only with use of sophisticated computational and experimental methods, design tools (CAD), technological processes (Rapid Prototyping, NC machining, precise casting), materials, etc."  

The following statement written at the end of the paper is also very interesting:

Authentic Conclusion by inventor " ... even first verbal information about TRIZ methodology impressed me a lot.  As an active inventor, I was very curious, what is about, but the truth overcame my expectation. I was fairly dragged into the systematic methodology of creative work even though we used only partly for evaluating an invention (engine) and innovation (propeller).  I assured myself, that knowledge of methodic processes fastens thinking and searching procedures and reduce random steps of improper solutions.  As an author of an invention being evaluated, I must say, that my concern of the methodology is not at the end, but in the beginning because a next ideas during evaluation arised"

*** This paper reports an extremely important invention, which has a huge potential of a lot of innovations in different application fields.  This poses us a big challenge worthy of significant endeavor.  I am very happy to learn that the two TRIZ experts in Czech have introduced TRIZ to the Inventor and are collaborating for further inventions and innovations by use of the TRIZ methodology.  The Inventor is preparing for his Web site with URL: .



Original Paper in PDF

Original Paper (in English)   (PDF, 609 KB, 6 pages)  Click Here. 


Edditor's Note Added [Toru Nakagawa (Aug 4, 2007)]   Photoes of the Experiments

The following 5 photoes are extracted from the CD-ROM which was kindly provided to me by the Authors at the ETRIA Conference site, and are posted here under the Authors' permission.

The day of this Experiment was May 12, 2004



Top of this page Nakagawa's introduction Original paper in PDF English (609 KB)   ETRIA TFC 2006 (Nakagawa Personal Rept.) Japanese paper PDF Japanese page


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Last updated on Aug. 17,  2007.     Access point:  Editor: