An automatic transmission includes a clutch device having a clutch hub, a clutch drum, a friction plate, a piston, and a hydraulic chamber. The clutch drum includes an outer-side cylindrical portion, a disc-shaped first radial portion extending radially inwardly, an axial portion extending axially from the first radial portion, and a disc-shaped second radial portion extending radially inwardly from the axial portion. The piston includes a pressing portion disposed between the first radial portion and the friction plate side, and a disc-shaped piston radial portion extending radially inwardly from the pressing portion. The hydraulic chamber is provided radially inwardly from the axial portion and on the non-friction-plate side of the piston radial portion. A comb-teeth portion is provided at a radially intermediate portion of the piston radial portion. The axial portion and the piston radial portion intersect with each other in a comb-teeth shape.

An automatic transmission includes a clutch device having a clutch hub, a clutch drum, a friction plate, a piston, and a hydraulic chamber. The clutch drum includes an outer-side cylindrical portion, a disc-shaped first radial portion extending radially inwardly, an axial portion extending axially from the first radial portion, and a disc-shaped second radial portion extending radially inwardly from the axial portion. The piston includes a pressing portion disposed between the first radial portion and the friction plate side, and a disc-shaped piston radial portion extending radially inwardly from the pressing portion. The hydraulic chamber is provided radially inwardly from the axial portion and on the non-friction-plate side of the piston radial portion. A comb-teeth portion is provided at a radially intermediate portion of the piston radial portion. The axial portion and the piston radial portion intersect with each other in a comb-teeth shape.

In some examples, a cone clutch assembly includes an inner cone member defining a first friction surface; an outer cone member defining a second friction surface opposing the first friction surface; and an independent friction member positioned between the first friction surface of the inner cone member and the second friction surface of the outer cone member. The inner cone member and outer cone member are configured to be selectively engaged and disengaged from each other. When the inner cone member is engaged with the outer cone member, the first friction surface of the inner cone member frictionally engages a third friction surface of the friction member, and the second friction surface of the outer cone member engages a fourth friction surface of the friction member such that rotational motion is transferred between the inner cone member and the outer cone member via the friction member.

A clutch device includes a clutch plate and a clutch outer. The clutch plate includes a plurality of teeth circumferentially disposed apart from each other. The clutch outer includes a bottom portion, a plurality of cover portions, and a plurality of openings. The bottom portion has a disc shape and is greater in diameter than the clutch plate. The cover portions axially extend from an outer peripheral edge of the bottom portion so as to cover the teeth. The cover portions are circumferentially disposed apart from each other. Each opening is disposed between each adjacent pair of the cover portions. Each opening is radially opened.

A clutch device includes a clutch plate and a clutch outer. The clutch plate includes a plurality of teeth circumferentially disposed apart from each other. The clutch outer includes a bottom portion, a plurality of cover portions, and a plurality of openings. The bottom portion has a disc shape and is greater in diameter than the clutch plate. The cover portions axially extend from an outer peripheral edge of the bottom portion so as to cover the teeth. The cover portions are circumferentially disposed apart from each other. Each opening is disposed between each adjacent pair of the cover portions. Each opening is radially opened.

Disclosed is a support structure for a ring gear (32), which includes: a clutch drum (6) coupled by spline fitting with the ring gear (32); and first and second snap rings (38, 39) mounted to a circumferential wall (62) of the clutch drum (6) and supporting the ring gear (32). The first snap ring (38) is positioned so as not to overlap with the ring gear (32) in a radial direction. The second snap ring (39) is positioned so as to overlap with the ring gear (32) in the radial direction. A length (a1) of the first snap ring (38) in the radial direction is longer than a length (a2) of the second snap ring (39) in the radial direction.

An automatic transmission includes a clutch device having a clutch hub, a clutch drum, a friction plate, a piston, and a hydraulic chamber. The clutch drum includes an outer-side cylindrical portion, a disc-shaped first radial portion extending radially inwardly, an axial portion extending axially from the first radial portion, and a disc-shaped second radial portion extending radially inwardly from the axial portion. The piston includes a pressing portion disposed between the first radial portion and the friction plate side, and a disc-shaped piston radial portion extending radially inwardly from the pressing portion. The hydraulic chamber is provided radially inwardly from the axial portion and on the non-friction-plate side of the piston radial portion. A comb-teeth portion is provided at a radially intermediate portion of the piston radial portion. The axial portion and the piston radial portion intersect with each other in a comb-teeth shape.

An automatic transmission includes a clutch device having a clutch hub, a clutch drum, a friction plate, a piston, and a hydraulic chamber. The clutch drum includes an outer-side cylindrical portion, a disc-shaped first radial portion extending radially inwardly, an axial portion extending axially from the first radial portion, and a disc-shaped second radial portion extending radially inwardly from the axial portion. The piston includes a pressing portion disposed between the first radial portion and the friction plate side, and a disc-shaped piston radial portion extending radially inwardly from the pressing portion. The hydraulic chamber is provided radially inwardly from the axial portion and on the non-friction-plate side of the piston radial portion. A comb-teeth portion is provided at a radially intermediate portion of the piston radial portion. The axial portion and the piston radial portion intersect with each other in a comb-teeth shape.

Disclosed is a support structure for a ring gear, which includes: a clutch drum coupled by spline fitting with the ring gear; and first and second snap rings mounted to a circumferential wall of the clutch drum and supporting the ring gear. The first snap ring is positioned so as not to overlap with the ring gear in a radial direction. The second snap ring is positioned so as to overlap with the ring gear in the radial direction. A length of the first snap ring in the radial direction is longer than a length of the second snap ring in the radial direction.

A clutch device includes a clutch plate and a clutch outer. The clutch plate includes a plurality of teeth circumferentially disposed apart from each other. The clutch outer includes a bottom portion, a plurality of cover portions, and a plurality of openings. The bottom portion has a disc shape and is greater in diameter than the clutch plate. The cover portions axially extend from an outer peripheral edge of the bottom portion so as to cover the teeth. The cover portions are circumferentially disposed apart from each other. Each opening is disposed between each adjacent pair of the cover portions. Each opening is radially opened.