Double clutch transmission

Patent metadata

Field	Value
Publication number	US-9863501-B2
Application number	US-201514833266-A
Country	US
Kind code	B2
Filing date	Aug 24, 2015
Priority date	Aug 28, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A dual-clutch transmission having first and second clutches which selectively engage to couple a drive shaft with a respective first and second input shaft. The input shafts are coaxially aligned with the first input shaft extending through the second input shaft. A transmission output shaft is coaxially aligned with and extends behind the input shafts. Either six, seven or eighth forward gears and at least two reverse gears are produced by gearwheels that are arranged in six gearwheel planes on the input and the output shafts and a countershaft. The gearwheel planes are sequentially arranged axially along the transmission. Depending on the shifting positions of eight interlocking shifting elements, when six forward gears are provided, the last forward gear is a direct gear. In contrast, when either seven or eight forward gears are provided, the last forward gear, in each case, is an overdrive gear.

First claim

The invention claimed is:

1. A dual-clutch transmission ( 1 ) comprising:
a first partial transmission and a second partial transmission;
a first transmission input shaft ( 2 ) for the first partial transmission and a separate, second transmission input shaft ( 3 ) for the second partial transmission;
a first frictional powershift clutch (K 1 ) is associated with the first transmission input shaft ( 2 ) which, when engaged, couples the first transmission input shaft ( 2 ) and the first partial transmission to a drive input shaft ( 4 );
a second frictional powershift clutch (K 2 ) is associated with the second transmission input shaft ( 3 ) which, when engaged, couples the second transmission input shaft ( 3 ) and the second partial transmission to the drive input shaft ( 4 );
a common transmission output shaft ( 5 ) for both of the first and the second partial transmissions;
the second transmission input shaft ( 3 ) is a hollow shaft which is coaxial with and partially surrounds, radially on an outside, the first transmission input shaft ( 2 );
the transmission output shaft ( 5 ) is coaxially with and is arranged axially behind the first transmission input shaft ( 2 ) and the second transmission input shaft ( 3 );
six gearwheel planes (a, b, c, d, e, f) being arranged sequentially, one behind another, to produce at least two reverse gears and either six forward gears, seven forward gears or eight forward gears,
gearwheels are positioned on either the first transmission input shaft ( 2 ), the second transmission input shaft ( 3 ), the transmission output shaft ( 5 ) and on a countershaft ( 6 ), the countershaft ( 6 ) extends parallel to the first and the second transmission input shafts and the transmission output shaft, and the gearwheels participate in torque transmission starting from the drive input shaft ( 4 ) in a direction toward the transmission output shaft ( 5 ), depending on shifting positions of eight interlocking shifting elements (S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 );
when six forward gears are provided, either a last or a sixth forward gear is a direct gear, and
when either seven or eight forward gears are provided, a last or, respectively, a seventh or an eighth forward gear is an overdrive gear.

2. The dual-clutch transmission according to claim 1 , wherein
a first gearwheel ( 7 ), positioned on the second transmission input shaft ( 3 ), and a second gearwheel ( 8 ), positioned on the countershaft ( 6 ), are both fixed gearwheels and form part of a first gearwheel plane (a), as viewed from the drive input shaft ( 4 ), located closest to the drive input shaft ( 4 );
a third gearwheel ( 9 ), positioned on the first transmission input shaft ( 2 ), is a fixed gearwheel and forms part of a second gearwheel plane (b), as viewed from the drive input shaft ( 4 ), located second closest to the drive input shaft ( 4 ), and a fourth gearwheel ( 10 ), positioned on the countershaft ( 6 ), is a loose wheel and forms part of the second gearwheel plane (b);
a fifth gearwheel ( 11 ), positioned on the transmission output shaft ( 5 ), and a sixth gearwheel ( 12 ), positioned on the countershaft ( 6 ), are both loose wheels, and both the fifth and the sixth loose wheels form part of a third gearwheel plane (c), as viewed from the drive input shaft ( 4 );
a seventh gearwheel ( 13 ), positioned on the transmission output shaft ( 5 ), and an eighth gearwheel ( 14 ), positioned on the countershaft ( 6 ), form a fourth gearwheel plane (d), as viewed from the drive input shaft ( 4 ), and both of the seventh and eighth gearwheels are loose wheels;
a ninth gearwheel ( 15 ), positioned on the transmission output shaft ( 5 ), is a loose wheel and forms part of a fifth gearwheel plane (e), the fifth gearwheel plane (e), as viewed from the drive input shaft ( 4 ), is located second furthest away from the drive input shaft ( 4 ), and a tenth gearwheel ( 16 ), positioned on the countershaft ( 6 ), is a fixed wheel and forms part of the fifth gearwheel plane (e); and
an eleventh gearwheel ( 17 ), positioned on the transmission output shaft ( 5 ), is a loose wheel and forms part of a sixth gearwheel plane (f), the sixth gearwheel plane (f), as viewed from the drive input shaft ( 4 ), is located furthest away from the drive input shaft ( 4 ), and a twelfth gearwheel ( 18 ), positioned on the countershaft ( 6 ), is a fixed wheel and forms part of the sixth gearwheel plane (f).

3. The dual-clutch transmission according to claim 2 , wherein
in an area of the second gearwheel plane (b), the first transmission input shaft ( 2 ) is associated with a first interlocking shifting element (S 1 ) such that when the first interlocking shifting element (S 1 ) is engaged, the first transmission input shaft ( 2 ) is coupled to the transmission output shaft ( 5 );
the fifth loose wheel ( 11 ) of the third gearwheel plane (c), positioned on the transmission output shaft ( 5 ), is associated with a second interlocking shifting element (S 2 ) such that when the second interlocking shifting element (S 2 ) is engaged, the fifth loose wheel ( 11 ) of the third gearwheel plane (c), positioned on the transmission output shaft ( 5 ), is coupled to the transmission output shaft ( 5 );
the seventh loose wheel ( 13 ) of the fourth gearwheel plane (d), positioned on the transmission output shaft ( 5 ), is associated with a third interlocking shifting element (S 3 ) such that when the third interlocking shifting element (S 3 ) is engaged, the seventh loose wheel ( 13 ) of the fourth gearwheel plane (d), positioned on the transmission output shaft ( 5 ), is coupled to the transmission output shaft ( 5 );
the ninth loose wheel ( 15 ) of the fifth gearwheel plane (e), positioned on the transmission output shaft ( 5 ), is associated with a fourth interlocking shifting element (S 4 ) such that when the fourth interlocking shifting element (S 4 ) is engaged, the ninth loose wheel ( 15 ) of the fifth gearwheel plane (e), positioned on the transmission output shaft ( 5 ), is coupled to the transmission output shaft ( 5 );
the eleventh loose wheel ( 17 ) of the sixth gearwheel plane (f), positioned on the transmission output shaft ( 5 ), is associated with a fifth interlocking shifting element (S 5 ) such that when the fifth interlocking shifting element (S 5 ) is engaged, the eleventh loose wheel ( 17 ) of the sixth gearwheel plane (f), positioned on the transmission output shaft ( 5 ), is coupled to the transmission output shaft ( 5 );
a sixth interlocking shifting element (S 6 ) is associated with the fourth loose wheel ( 10 ) of the second gearwheel plane (b) and the sixth loose wheel ( 12 ) of the third gearwheel plane (c), both positioned on the countershaft ( 6 ), such that when the sixth interlocking shifting element (S 6 ) is engaged, the fourth and sixth loose wheels ( 10 , 12 ) of the second gearwheel plane (b) and of the third gearwheel plane (c), positioned on the countershaft ( 6 ), are coupled to one another;
a seventh interlocking shifting element (S 7 ) is associated with the loose sixth wheel ( 12 ) of the third gearwheel plane (c) and the eighth loose wheel ( 14 ) of the fourth gearwheel plane (d), both positioned on the countershaft ( 6 ), such that when the seventh interlocking shifting element (S 7 ) is engaged, the sixth and eighth loose wheels ( 12 , 14 ) of the third gearwheel plane (c) and of the fourth gearwheel plane (d), positioned on the countershaft ( 6 ), are coupled to one another; and
an eighth interlocking shifting element (S 8 ) is associated with the eighth loose wheel ( 14 ) of the fourth gearwheel plane (d), positioned on the countershaft ( 6 ), such that when the eighth interlocking shifting element (S 8 ) is engaged, the eighth loose wheel ( 14 ) of the fourth gearwheel plane (d), positioned on the countershaft ( 6 ), is coupled to the countershaf

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Preuβ Michael
• Schepperle Bernd

Classifications

• F16H2003/0807

  with gear ratios in which the power is transferred by axially coupling idle gears to each other · CPC title

• F16H3/0915 Primary

  with coaxial input and output shafts · CPC title

• F16H2200/0052

  the gear ratios comprising six forward speeds · CPC title

• F16H2200/0056

  the gear ratios comprising seven forward speeds · CPC title

• F16H2200/006

  the gear ratios comprising eight forward speeds · CPC title