Lub iav planetary (tseem hu ua epicyclic iav) yog ib lub iav uas muaj ib lossis ntau lub iav sab nrauv (plam lub zog) tig mus ncig lub hauv nruab nrab (hnub) iav, txhua tus tuav hauv lub nplhaib iav (annulus). Qhov no compact thiab npaum tsim yog dav siv nyob rau hauv tsheb kis tau tus mob, industrial machinery ...
Kauv bevel iav yog ib hom bevel iav nrog nkhaus, oblique hniav uas muab smoother thiab ntsiag to ua hauj lwm piv rau ncaj bevel iav. Lawv tau dav siv nyob rau hauv daim ntawv thov uas yuav tsum tau siab torque kis tau tus mob ntawm txoj cai kaum (90 °), xws li automotive differen ...