A power transmission apparatus including a transmission, a case that accommodates the transmission, a counter drive gear to which power from the transmission is transmitted, a counter driven gear that meshes with the counter drive gear, and a drive pinion gear that is disposed and spaced apart in an axial direction from the counter driven gear and that rotates together with the counter driven gear, the power transmission apparatus.

A first valve is disposed in an oil passage through which the engaging pressure generated by a linear solenoid valve is supplied to A second brake. The first valve is closed when the second brake is released, so as to close the oil passage, and is opened when the second brake is engaged, so as to open the oil passage. A second valve is disposed in a lubricating oil passage through which lubricating oil is supplied to the second brake, and communicates with the linear solenoid valve. The second valve is opened when the engaging pressure is supplied from the linear solenoid valve, so as to open the lubricating oil passage, and is closed when no engaging pressure is generated by the linear solenoid valve.

A gearbox comprising: a first shaft (2) and a second shaft (1), one of the first and second shafts being an input shaft (1) for receiving a drive torque and the other being an output shaft (2) for providing a drive torque; two intermediate shafts (6, 7) by means of which the first and second shafts (2, 1) can be coupled together, each intermediate shaft being arranged so that: (a) it can be coupled to the first shaft (2) via a respective first torque path at any of a plurality of gear ratios (1st-8th), or the respective first torque path can be disengaged; and (b) it can be coupled to the second shaft (1) via a respective second torque path, or the respective second torque path can be disengaged; and a differential torque device (50) coupled between the intermediate shafts (6, 7), the differential torque device (50) being capable of transmitting a differential torque between the intermediate shafts (6, 7).

Lock-up clutch engagement hydraulic pressure learning control can be precisely performed by starting lock-up clutch engagement control and executing the lock-up clutch engagement hydraulic pressure learning control after execution of shift control is completed, in a case where the lock-up clutch engagement control is limited in a shift stage before execution of the shift control, when the shift control is executed in a state where a multi-disc lock-up clutch is released. Meanwhile, a decrease in fuel efficiency performance and a direct steering feeling is minimized by starting the lock-up clutch engagement control during shift control in a case where the lock-up clutch engagement control is not limited.

An automatic transmission is provided, which includes a brake including a fixed-side cylindrical member spline-coupled to a transmission case, a rotation-side cylindrical member coupled to a given rotating member, a plurality of friction plates disposed between the fixed-side cylindrical member and the rotation-side cylindrical member, and including a fixed-side friction plate configured to be spline-engaged with the fixed-side cylindrical member and a rotation-side friction plate configured to be spline-engaged with the rotation-side cylindrical member, and a piston configured to engage the plurality of friction plates. The automatic transmission includes a shock absorbing member disposed between a spline part of the transmission case and a spline part of the fixed-side cylindrical member and configured to absorb impact when the fixed-side cylindrical member rotates relative to the transmission case.

Disclosed is an 8-speed gearbox for a dual clutch transmission, with a particular gear arrangement of the gears on the countershaft, wherein the speed or reverse gear of a gear pair that is a permanently rotationally and axially fixed gear is the radially smaller of the gear pair. One or two cluster gears may be provided, each cluster gear having two gears axially paired attached to the countershaft by a shrink fit connection.

Provided is an automatic transmission with a compact arrangement that prevents rotation of a hub member, and efficiently supplies lubrication hydraulic oil to the friction plates. The automatic transmission comprises a brake in which a plurality of friction plates are arranged between the hub member and a drum member, wherein a biasing member, an engagement hydraulic pressure chamber, and a disengagement hydraulic pressure chamber are arranged radially inward of the friction plates at positions radially overlapping each other. The hub member comprises: a first hub member comprising a cylindrical portion having a splined region with which the friction plates are spline-engaged, wherein the first hub member s spline-engaged with a transmission casing; and a second hub member formed with a part of a lubrication oil supply passage, wherein the second hub member is fittingly engaged with the transmission casing such that it is connected to a valve body.

A power train device of a vehicle includes an engine and an automatic transmission. The automatic transmission is configured such that in a neutral state, multiple ones of multiple rotary elements forming a power transmission path other than a rotary element coupled to an input member and a rotary element coupled to an output member are in a non-restraining state. The multiple ones of the multiple rotary elements include a rotary element of a predetermined brake among multiple friction fastening elements, and the predetermined brake is fastened before a fuel supply upon an engine start.

A gear shift control system controls an actuator so that a pushing force will be a constant gearing-phase pushing force, during a gearing phase. The gear shift control system performs control on the basis of the number of rotation of the engine in the gearing phase, which is measured at the start of the gearing phase, so that the constant gearing-phase pushing force will increase as a number of rotation of the engine in the gearing phase increases. Thus, the hitting sound due to collision between the sleeve and the shift gear in shifting gears is reduced.

An automatic transmission which includes a first rotating member and a second rotating member is provided. The first rotating member includes an outer rotating member having a first outer power transmission part and an outer extending part, and an inner rotating member which is made of a different material from the outer rotating member and has a first inner power transmission part and an inner extending part. The outer and inner extending parts are coupled through a first extending part formed by axially joining them to each other at a caulking part. The second rotating member includes a second extending part having a recess indented on an opposite side of the first extending part. The caulking part has a protrusion protruding by being recessed from the first extending part to the second extending part. At least a part of the protrusion is located inside the recess.