Rhombic Mechanism

A Rhombic mechanism consists of two gears, four connecting rods, and two yoke for a displacer and a power piston. When the mechanism is idedally constructed, the displacer and the power piston have perfect straight motions. But in order to get the ideal motions, it is needed high accrate machinings.

LINK to: Rhombic Mechanism
Stroke and phase angle of the Rhombic mechanism are calculated here (in Japanese).

LINK to: 50 W Class Stirling Engine, Mini-Ecoboy
The experimental engine, Mini-Ecoboy uses the Rhombic mechanism.

Relative Papers (English)
Development of a Small 50W Class Stirling Engine: HIRATA, K., Sixth International Symposium On Marine Engineering, p.235-240, Oct. 2000.