Multi-ratio transmission

A multi-stage auto transmission for a motor vehicle, comprising:

• an input shaft (1) and an output shaft (2);
• first, second and third three planetary gear sets (P1, P2, P3), each of the first, the second and the third planetary gear sets comprising a sun gear, a ring gear and a carrier;
• first and second spur gear stages (S1, S2) being connected to a countershaft, disposed parallel to a longitudinal axis of the first, the second and the third planetary gear sets (P1, P2, P3), serving as the output shaft (2) of the transmission, and the first and second spur gear stages (S1, S2) being disposed inside a housing (G);
• at least third, fourth, fifth, sixth, seventh and eighth rotatable shafts (3, 4, 5, 6, 7, 8);
• at least five shift elements (03, 15, 24, 38, 45, 46, 56) comprising a brake (03) and first, second, third and fourth clutches (15, 24, 38, 45, 46, 56) which are selectively engagable to provide different transmission ratios between the input shaft (1) and the output shaft (2) such that eight forward gears and one reverse gear are implementable;
• the input shaft (1) being connected to the carrier of the first planetary gear set (P1) and connectable, by engagement of the first clutch (15), to the fifth shaft (5), and the fifth shaft (5) being connected to the ring gear of the second planetary gear set (P2) and the sun gear of the third planetary gear seat (P3);
• the ring gear of the first planetary gear set (P1) is connected to the sixth shaft (6) also being connected to the sun gear of the second planetary gear set (P2);
• the third shaft (3) being connected to the sun gear of the first planetary gear set (P1), being connectable to the housing (G) of the transmission by engagement of the brake (03) and being connectable, by engagement of the third clutch (38), to the eighth shaft (8), and the eighth shaft (8) being connected to the ring gear of the third planetary gear set (P3);
• the carrier of the second planetary gear set (P2) being connected to the fourth shaft (4), and the fourth shaft (4) being connectable to the output shaft (2) by the first spur gear stage (S1) and the second clutch (24);
• the carrier of the third planetary gear set (P3) being connected to the seventh shaft (7) which is also connected to a first spur gear (ST3) of the second spur gear stage (ST2), and a second spur gear (ST4) of the second spur gear stage (S2) being connected to the output shaft (2);
• and
• the fourth clutch (46, 56, 45) being engagable to block the second planetary gear set (P2).

A multi-stage automatic transmission for a motor vehicle, the transmission comprising:

• an input shaft (1) and an output shaft (2);
• first, second and third planetary gear sets (P1, P2, P3), each of the first, the second and the third planetary gear sets comprising a sun gear, a ring gear and a carrier;
• first and second spur gear stages (Si, S2) being connected to a countershaft, disposed parallel to a longitudinal axis of the first, the second and the third planetary gear sets (P1, P2, P3), serving as the output shaft (2) of the transmission, and the first and second spur gear stages (S1, S2) being disposed inside a housing (G) of the transmission;
• at least third, fourth, fifth, sixth, seventh and eighth rotatable shafts (3, 4, 5, 6, 7, 8)
• five shift elements (03, 15, 24, 38, 45, 46, 56) comprising a brake (03) and first, second, third, and fourth clutches (15, 24, 38, 45, 46, 56) which are selectively engagable to provide different transmission ratios between the input shaft (1) and the output shaft (2) such that eight forward gears and one reverse gear are implementable;
• the input shaft (1) being continuously connected to the carrier of the first planetary gear set (P1) and the input shaft (1) being connectable, via engagement of the first clutch (15), to the fifth shaft (5);
• the output shaft (2) being continuously connected to the second spur gear (ST4) of the second spur gear stage (S2);
• the third shaft (3) being continuously connected to the sun gear of the first planetary gear set (P1), the third shaft (3) being connectable, by engagement of the brake (03), to the housing (G) of the transmission, and the third shaft (3) being connectable, by engagement of the third clutch (38), to the eighth shaft (8);
• the fourth shaft (4) being continuously connected to the carrier of the second planetary gear set (P2) and the fourth shaft (4) being connectable to the output shaft (2) via the first spur gear stage (S1) and the second clutch (24);
• the fifth shaft (5) being continuously connected to the ring gear of the second planetary gear set (P2) and the sun gear of the third planetary gear seat (P3);
• the sixth shaft (6) being continuously connected to both the ring gear of the first planetary gear set (P1) and the sun gear of the second planetary gear set (P2);
• the seventh shaft (7) being continuously connected to the carrier of the third planetary gear set (P3) and the first spur gear (ST3) of the second spur gear stage (ST2);
• the eighth shaft (8) being continuously connected to the ring gear of the third planetary gear set (P3);
• and
• the fourth clutch (46, 56, 45) being engagable for blocking the second planetary gear set (P2).