Multi-speed gearbox

Abstract

The invention relates to a multi-speed gearbox having four planetary gear sets (P1, P2, P3, P4), eight rotatable shafts (1, 2, 3, 4, 5, 6, 7, 8) and six shift elements (03, 04, 13, 14, 17, 26), wherein the sun gear of the first planetary gear set (P1) is connected to the third shaft (3), which is detachably connected to the drive shaft (1) by means of a first clutch (13) and can be coupled to the housing (G) by means of a first brake (03). The drive shaft (1) can be detachably connected to the fourth shaft (4) which is connected to the planet carrier of the third planetary gear set (P3) by means of a second clutch (14), which can be coupled to the planet carrier of the first planetary gear set (P1) by means of a second brake (04) and is coupled to the housing (G). The drive shaft (1) can be detachably connected to the seventh shaft (7) which is connected to the sun gear of the fourth planetary gear set (P4) by means of a third clutch (17). The eighth shaft (8) is connected to the ring gear of the first planetary gear set (P1), to the sun gear of the second planetary gear set (P2) and to the sun gear of the third planetary gear set (P3). The fifth shaft (5) is connected to the planet carrier of the second planetary gear set (P2), to the ring gear of the third planetary gear set (P3) and to the ring gear of the fourth planetary gear set (P4). The sixth shaft (6) is connected to the ring gear of the second planetary gear set (P2) and can be detachably connected to the output shaft (2) of the gearbox which is connected to the planet carrier of the fourth planetary gear set (P4) by means of a fourth clutch (26).

Description

technical field [0001] The invention relates to a multi-stage transmission of planetary gear design according to the preamble of claim 1 , in particular an automatic transmission for motor vehicles. Background technique [0002] According to the prior art, automatic transmissions, in particular automatic transmissions for motor vehicles, comprise a plurality of planetary gearsets which are shifted by means of friction elements or switching elements, such as clutches and brakes, and which are usually connected to slipping and selectable It is connected to a starting element, such as a hydraulic torque converter or a hydraulic coupling, which is selectively equipped with a jumper clutch. [0003] Automatically shiftable vehicle transmissions of planetary gear design have generally been described several times in the prior art and are subject to constant further development and improvement. Therefore, these transmissions should require low structural outlay, in particular a sm...

AI Technical Summary

Problems solved by technology

[0006] According to the prior art, the shifting elements of multi-stage transmissions designed in this way, which are usually designed as multi-plate clutches or brakes, are hydraulically actuated, which disadvantageously leads to high hydraulic losses

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