In order to develop a compact and low cost Stirling engine, we have developed a displacer type Stirling engine named Mini-Ecoboy. It has simple heat exchangers and a Rhombic mechanism. Its target shaft power is 50 W at engine speed of 4000 rpm and mean pressure of 0.8 MPa using helium as working gas. This site shows the outline of the engine structure and the performance test.

However, the Mini-Ecoboy has not reached to enough performance yet. We hope that more detail information will be shown here after more improved.

The Mini-Ecoboy is designed and manufactured with follows concepts.
(1) It is aimed to the base model of genuine small-size Stirling engines.
(2) It has a simple structure and similar to high performance Stirling engines.
(3) Moreover, it should be built all of it by myself for low cost.

Basic Structure
Mini-Ecoboy is a displaccer type Stirling engine with unique components.
Heat Exchangers
The heat exchangers have simpler structure than that of previous high performance engines.
Piston Drive Mechanism
In order to realize high engine speed, a Rhombic mechanism is adopted.
Seal Device
A piston ring and a rod seal is shown here.
Hermetic Generator Set
In order to get higher power, it is needed to construct a hermetic generator set.
Performance of Mini-Ecoboy
The Mini-Ecoboy has not reached to target performance yet.
Drawings of Mini-Ecoboy
You can download the CAD data of the Mini-Ecoboy.