Patent attributes
A multi-speed transmission including a plurality of planetary gearsets and a plurality of selective couplers to achieve at least nine forward speed ratios is disclosed. The plurality of planetary gearsets may include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. The plurality of selective couplers may include a number of clutches and a number of brakes. The multi-speed transmission may have four planetary gearsets and six selective couplers. The six selective couplers may include two clutches and four brakes. The four planetary gearsets may include three minus planetary gearsets and one plus planetary gearset or two minus planetary gearsets and two plus planetary gearsets. The multi-speed transmission may include at least one Ravigneaux gearset.
