# US 2014/0190309 A1 · Motor vehicle drive train and method of operating a drive train > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190309 A1 - Document ID: US20140190309A1 - Status: Published application - Kind: A1 - Application number: 14/177,971 - Filed: 2014-02-11 - Published: 2014-07-10 - Earliest claimed: 2011-09-12 - Assignees: GETRAG Getriebe- und Zahnradfabrik Hermann Hagenmeyer GmbH & Cie KG - Applicants: GETRAG Getriebe- und Zahnradfabrik Hermann Hagenmeyer GmbH & Cie KG - Inventors: Hans-Peter Moosmann; Klaus-Dieter Wolf - Web page: https://patentgrep.com/patent/US20140190309A1 ## CPC - F16H 3/00: Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion (speed-changing or reversing mechanisms F16H59/00 - F16H63/00) - B60K 6/387: Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means - B60K 6/442: Series-parallel switching type - B60K 6/48: Parallel type - B60K 6/547: the transmission being a stepped gearing - B60K 17/02: characterised by arrangement, location, or kind of clutch - F16H 3/006: {power being selectively transmitted by parallel flow paths, e.g. dual clutch transmissions} - F16H 37/065: {with a plurality of driving or driven shafts (F16H37/0806 takes precedence)} - B60K 2006/4808: {Electric machine connected or connectable to gearbox output shaft} - F16H 48/19: consisting of two linked clutches - F16H 2200/0052: the gear ratios comprising six forward speeds - Y02T 10/62: Hybrid vehicles - Y10T 74/19074: Single drive plural driven - F16H: GEARING - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A drive train for a motor vehicle, having a drive unit which comprises a prime mover, a multi-step transmission and a power-splitting device which distributes the driving power between a first and a second drive shaft of a driven axle. The transmission comprises a transmission input and a first sub-transmission and a second sub-transmission. The prime mover is directly connected to the transmission input, wherein each of the two drive shafts is assigned a first and a second friction clutch. The first friction clutches connect the respective drive shaft to the first sub-transmission. The second friction clutches connect the respective drive shaft to the second sub-transmission. The first friction clutches and the second friction clutches form the power-splitting device. ## Claims ### Claim 1 A drive train for a motor vehicle, having a drive unit which comprises a prime mover, a multi-step transmission which comprises a transmission input and a first sub-transmission and a second sub-transmission, and having a power-splitting device which distributes the driving power between a first and a second drive shaft of a driven axle, wherein the prime mover is directly connected to the transmission input, wherein each of the two drive shafts is assigned a first and a second friction clutch, wherein the first friction clutches connect the respective drive shaft to the first sub-transmission and wherein the second friction clutches connect the respective drive shaft to the second sub-transmission, such that the first friction clutches and the second friction clutches form the power-splitting device. ### Claim 2 (depends on 1) The drive train as claimed in claim 1, wherein the prime mover comprises an internal combustion engine. ### Claim 3 (depends on 1) The drive train as claimed in claim 1, wherein the first sub-transmission comprises a first intermediate shaft, wherein gear ratios of the first sub-transmission are formed by wheel sets, which connect a transmission input shaft to the first intermediate shaft. ### Claim 4 (depends on 1) The drive train as claimed in claim 1, wherein the second sub-transmission comprises a second intermediate shaft, wherein gear ratios of the second sub-transmission are formed by wheel sets, which connect the transmission input shaft to the second intermediate shaft. ### Claim 5 (depends on 1) The drive train as claimed in claim 1, wherein the first friction clutches are arranged coaxially to a shaft of the first sub-transmission. ### Claim 6 (depends on 1) The drive train as claimed in claim 1, wherein the second friction clutches are arranged coaxially to a shaft of the second sub-transmission. ### Claim 7 (depends on 1) The drive train as claimed in claim 1, wherein the drive unit comprises an electric motor for supplying driving power, which can be connected to at least one of the sub-transmissions by means of a shifting clutch arrangement. ### Claim 8 (depends on 1) The drive train as claimed in claim 1, wherein the prime mover comprises an electric motor. ### Claim 9 (depends on 8) The drive train as claimed in claim 8, wherein the first sub-transmission comprises a single first gear ratio and/or wherein the second sub-transmission comprises a single second gear ratio. ### Claim 10 (depends on 9) The drive train as claimed in claim 9, wherein the multi-step transmission comprises a single transmission input shaft, on which two fixed wheels for the first gear ratio are fixed, which engage with loose wheels, which loose wheels can be shifted by means of the first friction clutches in the power flow, and on which single transmission input shaft two further fixed wheels for the second gear ratio are fixed, said further fixed wheels engaging with loose wheels, which can be shifted by means of the second friction clutches in the power flow, in order to distribute the driving power between the two drive shafts. ### Claim 11 (depends on 8) The drive train according to claim 8, wherein the drive unit comprises an internal combustion engine, which can be connected to the transmission input by means of a shifting clutch arrangement. ### Claim 12 (depends on 1) The drive train as claimed in claim 1, wherein the transmission input comprises a single transmission input shaft. ### Claim 13 (depends on 1) The drive train as claimed in claim 1, wherein both sub-transmissions comprise a starting gear ratio with the same transmission ratio, such that starting can take place by means of the two first and by means of the two second friction clutches. ### Claim 14 (depends on 1) The drive train as claimed in claim 1, wherein the first and second friction clutch of at least one of the first and the second drive shaft are arranged coaxially to the first and/or the second drive shaft. ### Claim 15 (depends on 1) The drive train as claimed in claim 1, wherein at least one of the first and the second friction clutches are configured as starting clutches. ### Claim 16 (depends on 1) The drive train as claimed in claim 1, wherein one of the two sub-transmissions comprises odd-numbered gear ratios and the other of the two sub-transmissions comprises even-numbered gear ratios. ### Claim 17 (depends on 1) The drive train as claimed in claim 1, wherein the first and the second drive shaft are connected to one another via a mechanical differential, the differential cage of which is connected to a longitudinal shaft, which is connected to a second driven axle. ### Claim 18 (depends on 1) The drive train as claimed in claim 1, wherein output members of the first and second friction clutches are connected via a transmission step to the drive shafts. ### Claim 19 (depends on 1) The drive train as claimed in one of the claim 1, wherein at least one of the first and the second friction clutches are identical in design. ### Claim 20 A method of operating a drive train, wherein the drive train comprises a drive unit and a transmission having a first and a second sub-transmission, wherein a first friction clutch is assigned to the first sub-transmission and wherein a second friction clutch is assigned to the second sub-transmission, wherein both sub-transmissions comprise a starting gear ratio with the same transmission ratio, wherein starting is achieved by simultaneously engaging the first and the second friction clutch. ### Claim 21 The method of operating a drive train, wherein the drive train comprises a drive unit, a transmission having a first and a second sub-transmission and also a driven axle having a first drive shaft and a second drive shaft, wherein a first and a second friction clutch are assigned to each of the two drive shafts, wherein the first friction clutches connect the respective drive shaft to the first sub-transmission and wherein the second friction clutches connect the respective drive shaft to the second sub-transmission, with the step of connecting the one drive shaft via the first friction clutch and the first sub-transmission to the drive unit and connecting the other drive shaft via the second friction clutch and the second sub-transmission to the drive unit when cornering.