Another elliptical stator design by Kobayashi in 1969 and
1972, with a concentric round rotor with four vanes,
incorporated an internal linkage to position the vanes
together as shown in Figure 5 [21]. A roller guide in a
cam carried the radial loading. A variation of this design
included a four-vane engine with an elliptical stator and
round rotor [22]. An external combustion chamber was
used along with a means for exhaust gas re-circulation.
A feature of this engine design was an internal linkage
that constrained the vanes’ motion.