Cranks 1 and 5 of parallel-crank linkage ABCD rotate about fixed axes A and D. Gear 3 is rigidly attached to (or integral with) connecting rod 4 and meshes with internal gear 2 which rotates about axis D. The dimensions of the links comply with the conditions: A͞B=D͞C=r, B͞C=A͞D and r₂-r₃=r, where r₂ and r₃ are the pitch radii of gears 2 and 3. The transmission ratio from crank 1 to gear 2 is i₁₂=ω₁/ω₂=r₂/r=r₂/(r₂-r₃)=z₂/(z₂-z₃) where ω₁ and ω₂ are the angular velocities of crank 1 and gear 2, and z₂ and z₃ are the numbers of teeth of gears 2 and 3. Crank 1 and gear 2 rotate in the same direction. Large transmission ratios can be obtained if there is a small difference between the numbers of teeth of the gears.
$2419$LrG,5L$