The present invention provides a planetary gear stage (2) for the gear box (1). Planet gear stage (2) is the ring gear (8), comprising a sun gear (9) and the planet carrier (4) for driving at least three planet shaft (6), is to the planet shaft (6) above, the contact in the radial direction mounted in a rotatable state by a surface (18) and at least one planet gear (5) of plain bearing apparatus having the axial direction of the contact surface (20) (7). Plain bearing device (7) comprises two bushes which are fixedly connected to the planet shaft (6) (12), each bush is fixed is cross section L-shaped, the contact surface of the radial direction (13 ) and a axial contact surface (14). Immobilized L-shaped bush (12) is attached to form a U-shaped cross-section, it is locked by the junction at both outer sides in the axial direction (15,16,24). At least part of the planetary gear (5) is located inside the U-shaped formed by a fixed L-shaped bush (12). Plain bearing device (7) further between the radial contact surface of the fixed L-shaped bush (12) and (13) the radial direction of the contact surfaces of the planetary gear (5) and (18), the diameter direction of sliding bearings (17), between the axial contact surface of the fixed L-shaped bush (12) and (14) the axial direction of the contact surfaces of the planetary gear (5) and (20), equipped with sliding bearing portion in the axial direction (19), the.
.FIELD 2