Abstract: A first friction member supporting member is provided on an inner circumference of a clutch retainer and a second friction member supporting member is provided on an outer circumference of a hub. A piston is disposed within the clutch retainer and is moved by hydraulic pressure to thereby generate friction. A plurality of circumference protrusions having different inner diameters in a radial direction are formed respectively on the first and second friction member supporting members. The circumference protrusion of the second friction member supporting member is disposed to overlap with an inner circumference portion of the circumference protrusion of the first friction member supporting member. Surfaces of the circumference protrusions of the first and second friction member supporting members facing with each other are formed as corresponding slanted surfaces and friction members are disposed on the slanted surfaces of the circumference protrusions.

Abstract: A planetary gear set for an automatic transmission of a vehicle includes a central shaft having a main lubrication path and a penetration hole connected with the main lubrication path, a sun gear, a pinion gear, a ring gear, a planet carrier, a first bearing disposed between a side of the sun gear and the planet carrier, a second bearing disposed between the planet carrier and the pinion gear, a clutch hub shaft, a sun gear lubrication path that connects the main lubrication path to the first bearing through the penetration hole, a pinion gear lubrication path that connects the main lubrication path to the second bearing through the penetration hole, and a sealing element disposed in a passageway connecting the pinion gear lubrication path and the sun gear lubrication path so as to close the passageway.

Abstract: A planetary gear set for an automatic transmission of a vehicle includes a central shaft having a main lubrication path and a penetration hole connected with the main lubrication path, a sun gear, a pinion gear, a ring gear, a planet carrier, a first bearing disposed between a side of the sun gear and the planet carrier, a second bearing disposed between the planet carrier and the pinion gear, a clutch hub shaft, a sun gear lubrication path that connects the main lubrication path to the first bearing through the penetration hole, a pinion gear lubrication path that connects the main lubrication path to the second bearing through the penetration hole, and a sealing element disposed in a passageway connecting the pinion gear lubrication path and the sun gear lubrication path so as to close the passageway.