Carrier 1 rotates about fixed axis A and is connected by turning pair B to planet gear 3 which meshes with fixed internal sun gear 2. The pitch radii of gears 2 and 3 comply with the condition: r₂=2r₃. When carrier 1 rotates about axis A, points on the pitch circle of gear 3 describe straight lines passing through point A. Any random point D on gear 3 describes an ellipse.
$2381$SG,Ge$