Power transmission with preselected ratios and a preselected output splitter
View Patent ↗A power transmission includes a plurality of ratio gear members, a planetary splitter, and a plurality of splitter control gear members. The ratio gear members are divided between two countershafts and two input clutches such that two power paths are provided from the transmission input. The splitter control gear members are disposed on the output of each of the ratio gears to establish input power paths to the planetary splitter, which delivers power to the transmission output shaft. By providing selective engagement of two selectively operable input clutches, a plurality of mechanical clutches and the planetary splitter gearset eight forward speed ratios are provided. A ninth forward ratio is provide by a mechanical clutch directly interconnecting one of the input clutches with the transmission output shaft in bypassing relation to the planetary splitter.
1. A power transmission comprising:
a power input shaft;
a first transmission input shaft;
a second transmission input shaft;
a first clutch selectively operatively connectible between said power input shaft and said first transmission input shaft;
a second clutch selectively operatively connectible between said power input shaft and said second transmission input shaft;
first and second ratio gears drivingly connected with said first transmission input shaft;
third and fourth ratio gears drivingly connected with said second transmission input shaft;
a first countershaft;
a second countershaft;
fifth and sixth ratio gears rotatably mounted on said first countershaft and meshing with said first and second ratio gears respectively;
first mechanical clutch means for selectively interconnecting said fifth and sixth ratio gears with said first countershaft;
seventh and eighth ratio gears rotatably mounted on said second countershaft;
second mechanical clutch means for selectively interconnecting said seventh and eighth ratio gears with said second countershaft;
a splitter planetary gearset having a first member, a second member continuously connected with a stationary transmission member, and a third member continuously connected with a transmission output shaft;
a first splitter input gear continuously connected with said first member;
a second splitter input gear continuously connected with said third member and said output shaft;
a first splitter control gear meshing with said first splitter input gear and being rotatably mounted on said first countershaft;
a second splitter control gear meshing with said second splitter input gear and being rotatably mounted on said first countershaft;
a third mechanical clutch means for selectively connecting said first and second splitter control gears with said first countershaft;
a third splitter control gear rotatably mounted on said second countershaft;
a fourth splitter control gear rotatably mounted on said second countershaft;
a fourth mechanical clutch means for selectively connecting said third and fourth splitter control gears with said second countershaft;
said first clutch, said first mechanical clutch, and said third mechanical clutch being selectively operable to establish four forward speed ratios between said first transmission input shaft and said transmission output shaft; and
said second clutch, said second mechanical clutch, and said fourth mechanical clutch being operable to establish four forward speed ratios between said second transmission input shaft and said transmission output shaft.
2. The power transmission defined in claim 1 further comprising:
fifth mechanical clutch means selectively operable to connect said first transmission input shaft with said transmission output shaft to establish a direct drive connection between said first input shaft and said output shaft.
3. The power transmission defined in claim 2 further comprising:
said fifth mechanical clutch being operable to connect said first input shaft with said output shaft in bypassing relation to said splitter planetary gearset.