PLANETARY BEARING STRUCTURE

摘要

Disclosed is a planetary bearing structure that does not require forced lubrication of a plain-bearing-using planetary bearing and that lubricates by reliably supplying oil to sliding surfaces using a simple configuration. The planetary bearing structure is provided with both a planetary pin (30) affixed to a carrier (21), and a planetary gear (40) wherein a plain bearing (50) is attached to the inner peripheral surface of a shaft hole (40a); the planetary pin (30) rotatably supports the planetary gear (40) via the plain bearing (50); gear end surfaces (41L, 41R) rotate with a left and right pair of gaps (SL, SR) formed between the opposing wall surfaces (21L, 21R) of the carrier (21); spiral grooves (42L, 42R) facing in opposite directions are provided on either the gear end surfaces (41L, 41R) or the opposing wall surfaces (21L, 21R) at the gaps (SL, SR); and by means of the planetary bearing structure being immersed in lubricating oil, a lubricating oil pathway is formed wherein the lubricating oil introduced from the gap (SR) on the intake side passes between the planetary pin (30) and the plain bearing (50), and is discharged from the gap (SL) on the discharge side.