Round eccentric 1 rotates about fixed axis A. Ring gear 2 rotates about axis 0 of eccentric 1 and meshes with internal gear 5. Link 3 has slots b which slide along pins a of ring gear 2. Internal gear 5 rotates about axis A. Link 3 slides along hub 6 of eccentric 1 and is kept from rotating by fixed pin 4 along which slot d of link 3 slides. Thus gear 2 has circular translational motion at the same velocity as centre 0 of eccentric 1. Therefore, the transmission ratio from eccentric 1 to gear 5 is i₁₅=A͞O/r₅=(z₅-z₂)/z₅ where r₅ is the pitch radius of gear 5, and z₂ and z₅ are the numbers of teeth of gears 2 and 5. Large transmission ratios can be obtained if there is a small difference between the numbers of teeth of the gears.
$2406$LrG,4L$