Powertrain for a vehicle and method for carrying out load changes

Patent metadata

Field	Value
Publication number	US-9822860-B2
Application number	US-201414774224-A
Country	US
Kind code	B2
Filing date	Feb 12, 2014
Priority date	Mar 12, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A drive-train for a vehicle with at least one electric drive, which can be coupled via a driveshaft ( 2 ) to at least a first transmission ratio stage (i 1 ) and a second transmission ratio stage (i 2 ). At least one shifting mechanism is provided for engaging the transmission ratio stages (i 1 , i 2 ). To carry out powershifts, the shifting mechanism includes at least one interlocking shifting element ( 5 ) and at least one frictional shifting element ( 6, 6 A). Each of the transmission ratio stages (i 1 , i 2 ) can be engaged by the interlocking shifting element ( 5 ) and at least one of the transmission ratio stages (i 2 ) can be engaged both by the interlocking shifting element ( 5 ) and by the frictional shifting element ( 6 ). Methods for carrying out a powershift, between a frictional shifting element ( 6, 6 A) and an interlocking shifting element ( 5 ) in the drive-train, are also disclosed.

First claim

The invention claimed is:

1. A drive-train for a vehicle, with at least one electric drive (EM), which is couplable, via a driveshaft, to at least a first transmission ratio stage (i 1 ) and a second transmission ratio stage (i 2 ),
at least one shifting mechanism for engaging the first and the second transmission ratio stages (i 1 , i 2 ), and the at least one shifting mechanism comprising at least one interlocking shifting element ( 5 ) and at least one frictional shifting element ( 6 , 6 A) for carrying out powershifts,
each of the first and the second transmission ratio stages (i 1 , i 2 ) being engagable by the interlocking shifting element ( 5 ), and
at least one of the first and the second transmission ratio stages (i 2 ) being engagable by both of the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 ),
wherein the first and the second transmission ratio stages (i 1 , i 2 ) are realized by a planetary gearset,
a sun gear ( 12 ) of the planetary gearset ( 11 ) is connected to the driveshaft ( 2 ), a planetary carrier ( 13 ) is connectable, by the frictional shifting element ( 6 ) to the driveshaft, and
a ring gear ( 15 ) of the planetary gearset ( 11 ) is connectable, by the interlocking shifting element ( 5 ), to either the driveshaft ( 2 ) or a housing ( 16 ).

2. The drive-train according to claim 1 , wherein a direct drive is engagable, via the planetary gearset ( 11 ), by engaging the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 ).

3. The drive-train according to claim 1 , wherein the electric drive is an electric machine (EM).

4. The drive-train according to claim 1 , wherein the frictional shifting element ( 6 ) is a ‘normally open’ disk clutch.

5. The drive-train according to claim 1 , wherein the interlocking shifting element ( 5 ) is a claw clutch.

6. A method of carrying out a powershift between a frictional shifting element ( 6 , 6 A) and an interlocking shifting element ( 5 ) in a drive-train with at least one electric drive (EM), which is couplable, via a driveshaft, to at least a first transmission ratio stage (i 1 ) and a second transmission ratio stage (i 2 ), at least one shifting mechanism for engaging the first and the second transmission ratio stages (i 1 , i 2 ), the shifting mechanism comprises at least one of the interlocking shifting element ( 5 ) and at least one of the frictional shifting element ( 6 , 6 A), each of the first and the second transmission ratio stages (i 1 , i 2 ) is engagable by the interlocking shifting element ( 5 ) and at least one of the first and the second transmission ratio stages (i 2 ) is engagable by both of the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 ), the first and the second transmission ratio stages (i 1 , i 2 ) are realized by a planetary gearset, a sun gear ( 12 ) of the planetary gearset ( 11 ) is connected to the driveshaft ( 2 ), a planetary carrier ( 13 ) is connectable, by the frictional shifting element ( 6 ), to the driveshaft ( 2 ), and a ring gear ( 15 ) of the planetary gearset ( 11 ) is connectable, by the interlocking shifting element ( 5 ), to either the driveshaft ( 2 ) or a housing ( 16 ), the method comprising:
detecting meshing movement, via a path sensor, during a powershift from an engaged frictional shifting element ( 6 , 6 A) to a disengaged interlocking shifting element ( 5 ).

7. The method according to claim 6 , further comprising disengaging the frictional shifting element ( 6 , 6 A) when, based on the detected meshing movement, complete meshing is recognized.

8. The method according to claim 6 , further comprising slowly disengaging the frictional shifting element ( 6 , 6 A) when, based on the detected meshing movement, a tooth-on-tooth position at the interlocking shifting element ( 5 ) is recognized in order to produce a rotational speed difference.

9. The method according to claim 8 , further comprising, after a rotational speed difference is produced, again carrying out engaging of the interlocking shifting element ( 5 ) and opening disengaging the frictional shifting element ( 6 , 6 A) when the meshing movement is completed.

10. The method according to claim 8 , further comprising, as an emergency measure, resolving a tooth-on-tooth position by carrying out a load reduction to allow complete meshing.

11. The method according to claim 6 , further comprising:
if, on a basis of the detected meshing movement, only partial meshing of the interlocking shifting element ( 5 ) is recognized, again disengaging the interlocking shifting element ( 5 ) and then partially disengaging the frictional shifting element ( 6 , 6 A) to produce a slipping condition, and
again engaging the frictional shifting element ( 6 , 6 A) so that a new orientation is produced, at the interlocking shifting element ( 5 ), in order to resolve a tooth-on-tooth position.

12. A method of carrying out a powershift between a frictional shifting element ( 6 , 6 A) and an interlocking shifting element ( 5 ) in a drive-train for a vehicle, with at least one electric drive (EM), which is couplable, via a driveshaft, to at least a first transmission ratio stage (i 1 ) and a second transmission ratio stage (i 2 ), at least one shifting mechanism for engaging the first and the second transmission ratio stages (i 1 , i 2 ), the at least one shifting mechanism comprises the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 , 6 A) for carrying out powershifts, each of the first and the second transmission ratio stages (i 1 , i 2 ) is engagable by the interlocking shifting element ( 5 ) and at least one of the first and the second transmission ratio stages (i 2 ) is engagable by both of the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 ), the first and the second transmission ratio stages (i 1 , i 2 ) are realized by a planetary gearset, a sun gear ( 12 ) of the planetary gearset ( 11 ) is connected to the driveshaft ( 2 ), a planetary carrier ( 13 ) is connectable, by the frictional shifting element ( 6 ), to the driveshaft ( 2 ), and a ring gear ( 15 ) of the planetary gearset ( 11 ) is connectable, by the interlocking shifting element ( 5 ), to either the driveshaft ( 2 ) or a housing ( 16 ), the method comprising:
carrying out a powershift depending on at least one of an evaluation of vehicle data and topographical data.

13. A method of carrying out a powershift between a frictional shifting element ( 6 , 6 A) and an interlocking shifting element ( 5 ) in a drive-train for a vehicle, with at least one electric drive (EM), which is couplable via a driveshaft to at least a first transmission ratio stage (i 1 ) and a second transmission ratio stage (i 2 ), at least one shifting mechanism for engaging the first and the second transmission ratio stages (i 1 , i 2 ), the at least one shifting mechanism comprises the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 , 6 A) for carrying out powershifts, each of the first and the second transmission ratio stages (i 1 , i 2 ) is engagable by the interlocking shifting element ( 5 ) and at least one of the first and the second transmission ratio stages (i 2 ) is engagable by both of the interlocking shifting element ( 5 ) and the frictional shifting element ( 6 ), the first and the second transmission ratio stages (i 1 , i 2 ) are realized by a planetary gearset, a sun ear ( 12 ) of the planetary gearset ( 11 ) is connected to the driveshaft ( 2 ), a planetary carrier ( 13 ) is connectable, by the frictional shifting element ( 6 ), the driveshaft ( 2 ), and a ring gear ( 15 ) of the planetary gears

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Kaltenbach Johannes
• Reisch Matthias
• Kehr Ulrich
• Preuβ Michael
• Bornträger Kai

Classifications

• F16H2200/2094

  using positive clutches, e.g. dog clutches · CPC title

• F16H2200/2033

  with one engaging means · CPC title

• B60K1/00

  Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) · CPC title

• F16H2306/46

  Uncoupling of current gear · CPC title

• F16H2061/047

  by preventing or solving a tooth butt situation upon engagement failure due to misalignment of teeth · CPC title