Multi-speed planetary transmission mechanisms with a stationary planetary member and two brakes
View Patent ↗The family of transmissions has a plurality of members that can be utilized in powertrains to provide six forward speed ratios and a reverse speed ratio. The transmission family members include three planetary gear sets having five torque-transmitting mechanisms, two fixed interconnections, and one grounded planetary gear member. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The five torque-transmitting mechanisms provide interconnections between various gear members, the fixed interconnections, the input shaft, the output shaft, and the transmission housing, and are operated in combinations of two to establish six forward speed ratios and one reverse speed ratio.
1. A multi-speed transmission comprising:
an input shaft;
an output shaft;
first, second and third planetary gear sets each having first, second and third members;
said input shaft being continuously interconnected with a member of said second or third planetary gear set, and said output shaft being continuously interconnected with another member of said second or third planetary gear set;
a first interconnecting member continuously interconnecting said first member of said first planetary gear set with said first member of said second planetary gear set;
a second interconnecting member continuously interconnecting said second member of said second planetary gear set with said first member of said third planetary gear set;
wherein said second member of said first planetary gear set is continuously connected with a stationary member;
a first torque-transmitting mechanism selectively interconnecting a member of said first planetary gear set with said stationary member;
a second torque-transmitting mechanism selectively interconnecting a member of said second or third planetary gear set with said stationary member;
a third torque-transmitting mechanism selectively interconnecting a member of said first planetary gear set with a member of said second or third planetary gear set;
a fourth torque-transmitting mechanism selectively interconnecting a member of said third planetary gear set with a member of said first or second planetary gear set, said pair of members interconnected by said fourth torque-transmitting mechanism being different from the pair of members interconnected by said third torque-transmitting mechanism;
a fifth torque-transmitting mechanism selectively interconnecting a member of said first, second or third planetary gear set with another member of said first, second or third planetary gear set, said pair of members interconnected by said fifth torque-transmitting mechanism being different from the pair of members interconnected by said third or fourth torque-transmitting mechanism; and
said torque-transmitting mechanisms being engaged in combinations of two to establish at least six forward speed ratios and one reverse speed ratio between said input shaft and said output shaft.
2. The transmission defined in claim 1 , wherein said first end second torque-transmitting mechanisms comprise brakes, and said third, fourth, and fifth torque-transmitting mechanisms comprise clutches.
3. The transmission defined in claim 1 , wherein planet carrier assembly members of each of said planetary gear sets are single-pinion carriers.
4. The transmission defined in claim 1 , wherein at least one planet carrier assembly member of said planetary gear sets is a double-pinion carrier.
5. A multi-speed transmission comprising:
an input shaft;
an output shaft;
first, second and third planetary gear sets each having first, second and third members;
said input shaft being continuously interconnected with a member of said second or third planetary gear set, and said output shaft being continuously interconnected with another member of said second or third planetary gear set;
a first interconnecting member continuously interconnecting said first member of said first planetary gear set wit said first member of said second planetary gear set;
a second interconnecting member continuously interconnecting said second member of said second planetary gear set with said first member of said third planetary gear set;
wherein said second member of said first planetary gear set is continuously connected with a stationary member;
a first torque-transmitting mechanism selectively interconnecting a member of said first planetary gear set with said stationary member;
a second torque-transmitting mechanism selectively interconnecting a member of said second or third planetary gear set with said stationary member;
a third torque-transmitting mechanism selectively interconnecting a member of said first planetary gear set with a member of said second or third planetary gear set;
a fourth torque-transmitting mechanism selectively interconnecting a member of said third planetary gear set with a member of said first or second planetary gear set, said pair of members interconnected by said fourth torque-transmitting mechanism being, different from the pair of members interconnected by said third torque-transmitting mechanism;
a fifth torque-transmitting mechanism selectively interconnecting a member of said first second or third planetary gear set with another member of said first, second or third planetary gear set, said pair of members interconnected by said fifth torque-transmitting mechanism being different from the pair of members interconnected by said third or fourth torque-transmitting mechanism; and
wherein said first and second torque-transmitting mechanisms comprise brakes, and said third, fourth, and fifth torque-transmitting mechanisms comprise clutches, and planet carrier assembly members of each of said planetary gear sets are single-pinion carriers;
said torque-transmitting mechanisms being engaged in combinations of two to establish at least six forward speed ratios and one reverse speed ratio between said input shaft and said output shaft.