A family of transmission gearing arrangements each establish at least one reverse gear ratio and between nine and fifteen forward gear ratios. A shiftable gearing arrangement establishes a variety of speed ratios between the input and a first shaft. In some embodiments, a fixed speed ratio is established upstream or downstream of the shiftable gearing arrangement. In reverse and low gear ratios, a low clutch couples the first shaft to the output. In the high gear ratios, a combining planetary gear set establishes a linear speed relationship between the first shaft, a second shaft rotating at a speed proportional to the input, and the output.

A family of transmission gearing arrangements each establish at least one reverse gear ratio and between nine and fifteen forward gear ratios. A shiftable gearing arrangement establishes a variety of speed ratios between the input and a first shaft. In some embodiments, a fixed speed ratio is established upstream or downstream of the shiftable gearing arrangement. In reverse and low gear ratios, a low clutch couples the first shaft to the output. In the high gear ratios, a combining planetary gear set establishes a linear speed relationship between the first shaft, a second shaft rotating at a speed proportional to the input, and the output.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque of the engine, a first planetary gear set including first, second, and third rotation elements, a second planetary gear set including fourth, fifth, and sixth rotation elements, a third planetary gear set including seventh, eighth, and ninth rotation elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, and seven friction elements disposed to selectively connect the rotation elements and to selectively connect the rotation elements with a transmission housing.

A family of transmission gearing arrangements provides between eight and ten forward speed ratios and a reverse speed ratio. Three planetary gear sets are located on the input axis and a fourth planetary gear set is located on an offset axis. Axis transfer gears convey power between the input axis and the offset axis. One axis transfer gear is supported by a front support while another is supported by a center support. The center support also supports a clutch module and supplies pressurized fluid to engage the clutches in the clutch module.

A family of transmission gearing arrangements provides between eight and ten forward speed ratios and a reverse speed ratio. Three planetary gear sets are located on the input axis and a fourth planetary gear set is located on an offset axis. Axis transfer gears convey power between the input axis and the offset axis. One axis transfer gear is supported by a front support while another is supported by a center support. The center support also supports a clutch module and supplies pressurized fluid to engage the clutches in the clutch module.

A transmission device, wherein the compound planetary gear mechanism increases the speed of the power transmitted to the input element and transmits the resultant power to the first and the second output elements when the fixable element is non-rotatably held stationary by the first brake; and the first and the second clutches are disposed on a side closer in the axial direction to the compound planetary gear mechanism than the first and the second planetary gear mechanisms.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque, a first planetary gear set including first, second, and third rotation elements, a second planetary gear set including fourth, fifth, and sixth rotation elements, a third planetary gear set including seventh, eighth, and ninth rotation elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, and seven friction elements disposed between at least one rotation element among the twelve rotation elements and another rotation element or the input shaft, or between at least one rotation element among the twelve rotation elements and a transmission housing.

Transmissions with at least three gearing-arrangements with similar first and second gearing-arrangements that produce a number of transmissions having an eleven forward-speed and two reverse-speed ratios, having ten forward-speed and three reverse-speed ratios, and having five forward-speed and one reverse-speed ratios by selective engagement of three shift-elements in various combinations. Some embodiments include four simple planetary-gearsets and six shift-elements of which two or three are brakes. Another embodiment includes a double-pinion planetary-gearset and six shift-elements of which three are brakes. Other embodiments include three simple planetary-gearsets and five shift-elements of which one or two are brakes.

Transmissions with at least three gearing-arrangements with similar first and second gearing-arrangements that produce a number of transmissions having an eleven forward-speed and two reverse-speed ratios, having ten forward-speed and three reverse-speed ratios, and having five forward-speed and one reverse-speed ratios by selective engagement of three shift-elements in various combinations. Some embodiments include four simple planetary-gearsets and six shift-elements of which two or three are brakes. Another embodiment includes a double-pinion planetary-gearset and six shift-elements of which three are brakes. Other embodiments include three simple planetary-gearsets and five shift-elements of which one or two are brakes.

A phasing system is provided. A phase angle between the gear hub and the cradle rotor can be driven by a planetary actuator. In some non-limiting examples, an input shaft rotationally coupled between a rotary actuator for rotation therewith. Rotation of the input shaft can unlock relative rotation between the cradle rotor and the gear hub. In some non-limiting examples, the phasing system can include a gear hub and a cradle rotor, and a torsion spring arrange therebetween. The torsion spring can be configured to apply an internal torque load between the gear hub and the cradle rotor to offset an external torque load applied to the gear hub or the cradle rotor.