Patent ID: 7211022

Claim:
A multi-step reduction gear transmission of planetary construction, for a motor vehicle, comprising: a drive shaft ( 1 ) and a power take-off shaft ( 2 ), are arranged in a housing (G), first, second and third planetary sets (P 1 , P 2 , P 3 ), at least seven rotating shafts ( 1 , 2 , 3 , 4 , 5 , 6 , 7 ), including the drive shaft ( 1 ) and the take-off shaft ( 2 ), as well as at least six shift elements ( 03 and 04 , 16 , 36 , 37 , 57 ), including brakes ( 03 , 04 ) and clutches ( 16 , 36 , 37 , 57 ) whose selective engagement results in various transmission relationships between the drive shaft ( 1 ) and the power take-off shaft ( 2 ) so that seven forward gears and one reverse gear can be achieved, the drive shaft ( 1 ) is constantly connected with a sun wheel of the first planetary set (P 1 ) and is connected by a first clutch ( 16 ) to a sixth shaft ( 6 ), which is connected with a carrier of the second planetary set (P 2 ) and a carrier of the third planetary set (P 3 ), the power take-off shaft ( 2 ) is constantly connected with a ring gear of the second planetary set (P 2 ) and a ring gear of the third planetary set (P 3 ), a carrier of the first planetary set (P 1 ) is constantly connected to a third shaft ( 3 ) and the carrier of the first planetary set (P 1 ) is detachably connected, by a first brake ( 03 ), to the housing (G) and detachably connected, by a second clutch ( 36 ), to a sixth shaft ( 6 ) and, by a third clutch ( 37 ), to a seventh shaft ( 7 ), the seventh shaft ( 7 ) is constantly connected to a sun gear of the third planetary set (P 3 ) and is detachably connected by a fourth clutch ( 57 ) to a fifth shaft ( 5 ) which is constantly connected to a ring gear of the first planetary set (P 1 ), and a fourth shaft ( 4 ) is constantly connected to a sun gear of the second planetary set (P 2 ) and is detachably coupled by a second brake ( 04 ) to the housing (G).