A transmission arrangement (10) for a motor vehicle includes an electric machine (14) arranged in a first housing part (12). A second housing part (16) is configured for accommodating a component (18) of an internal combustion engine. The electric machine (14) and the internal combustion engine are connectable to an output shaft by a transmission (20). The first and second housing parts (12, 16) are connected to each other and form a common interior space (30). An intermediate wall (34) delimits a subspace (36) from the remaining interior space (30). The electric machine (14) is arranged in the subspace (36). At least one planetary gear set includes at least one element supported at the intermediate wall (34).

A power transmission device includes a motor including a rotor, a first planetary reduction gear connected downstream of the motor, a second planetary reduction gear connected downstream of the first planetary reduction gear, a differential gear connected downstream of the second planetary reduction gear, and a drive shaft connected downstream of the differential gear. The first planetary reduction gear includes a sun gear and a pinion gear that is a stepless pinion. The second planetary reduction gear includes a sun gear and a pinion gear that is a stepped pinion. The drive shafts is penetrating an inner circumference of the rotor of the motor, an inner circumference of the sun gear of the first planetary reduction gear, and an inner circumference of the sun gear of the second planetary reduction gear.

A power transmission device includes a motor, a first planetary reduction gear connected downstream of the motor, a second planetary reduction gear connected downstream of the first planetary reduction gear, a differential gear connected downstream of the second planetary reduction gear, a drive shaft connected downstream of the differential gear, and a case member. The drive shaft penetrates an inner circumference of a rotor of the motor, an inner circumference of a sun gear of the first planetary reduction gear, and an inner circumference of a sun gear of the second planetary reduction gear. A portion of the differential case positioned between the first planetary reduction gear and the second planetary reduction gear is supported at an inner circumference side of a portion of the case member with a first bearing being interposed.

An automatic transmission includes a starting clutch which connects and disconnects motive power between an engine and a transmission mechanism. The starting clutch includes a clutch hub connected to the engine, a clutch drum connected to the transmission mechanism, a friction plate provided between the clutch hub and the clutch drum, and a piston which presses the friction plate. The clutch drum has a radial-direction portion extending from an end portion of the outer-side cylindrical portion on a first axial-direction side to the radial-direction inner side, and an annular oil dam member extending from an end portion of the outer-side cylindrical portion on a second axial-direction side to the radial-direction inner side to immerse the friction plate in oil supplied from the radial-direction inner side toward the outer side, together with the outer-side cylindrical portion and the radial-direction portion.

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 intermediate wall is provided with a return oil hole through which oil discharged from a friction engagement device returns toward an oil reservoir. A chain drive is disposed adjacent to the intermediate wall. The chain drive transmits a driving force from an input member and/or a rotary electric machine to an oil pump. There is provided an oil guide through which oil flowing through the return oil hole is guided to a region other than a chain placement region inside a case. The chain placement region is a region where a chain of the chain drive is placed.

A power transmission device includes a motor including a rotor, a first planetary reduction gear connected downstream of the motor, a second planetary reduction gear connected downstream of the first planetary reduction gear, a differential gear connected downstream of the second planetary reduction gear, and a drive shaft connected downstream of the differential gear. The first planetary reduction gear includes a sun gear and a pinion gear that is a stepless pinion. The second planetary reduction gear includes a sun gear and a pinion gear that is a stepped pinion. The drive shafts is penetrating an inner circumference of the rotor of the motor, an inner circumference of the sun gear of the first planetary reduction gear, and an inner circumference of the sun gear of the second planetary reduction gear.

A power transmission device including a planetary gear, a differential gear and a differential case. The planetary gear includes a carrier, and pinion gears supported by pinion shafts. The differential gear includes a pair of bevel gears supported by a bevel gear shaft, and side gears engaged with the bevel gears. The carrier defines pinion shaft insertion holes in which pinion shafts are respectively inserted. The differential case defines bevel gear shaft insertion holes in which the bevel gear shaft is inserted. A straight line that penetrates the bevel gear shaft insertion holes overlaps with the pinion shaft insertion holes in a circumferential direction, and the bevel gear shaft passes through a center of a circle that connects the pinion shaft insertion holes. When viewed along an axial direction, the pinion shafts do not overlap the side gears, with the side gears being arranged radially inwardly than the pinion shafts.

A transmission device is provided in which a parking mechanism and a breather chamber are provided within a power-transmission case, the breather chamber being present at least above an input gear and providing communication between the interior of the power-transmission case and the exterior of the power-transmission case, wherein the breather chamber, which is present at least above the input gear and providing communication between the interior of the power-transmission case and the exterior of the power-transmission case, extends further outward than the input gear in an arrangement direction of the input gear and the output gear, and part of the parking mechanism is disposed within the breather chamber. Thus, it is possible to increase the capacity of a breather chamber while avoiding an increase in the size of a transmission device.

The support structure comprises a main body, a base part, and a ring gear having internal teething. The main body has at least one axle element for rotatably mounting the at least one gear wheel, or at least one connection point for an axle element for rotatably mounting the one gear wheel. The ring gear is mounted with an axial end on the base part and is designed to be used as an outer gear wheel of a planetary gear drive. The internal teething of the ring gear has a plurality of tooth elements which extend in each case from a tooth foot to a tooth head in the radial direction relative to a centre axis of the ring gear. An intermediate space, exposing a region of the tooth head at least of individual tooth elements or a number thereof, is provided between the internal teething and the base part.