Multi-speed automatic transmission

Patent metadata

Field	Value
Publication number	US-2016245370-A1
Application number	US-201615010674-A
Country	US
Kind code	A1
Filing date	Jan 29, 2016
Priority date	Jan 30, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

An automatic transmission has eight rotatable shafts ( 1 to 8 ), four planetary gear sets (RS 1 to RS 4 ), and seven shift elements (B 1 , B 2 , B 3 , C 1 , C 2 , C 3 , C 4 ) for shifting several forward gears and one reverse gear. The first shaft ( 1 ) is the drive shaft (AN) of the transmission. A second element (ST 3 ) of the third planetary gear set (RS 3 ) forms the output shaft (AB) of the transmission. As the third shaft ( 3 ), a second element (ST 1 ) of the first planetary gear set (RS 1 ) and a third element (HO 2 ) of the second planetary gear set (RS 2 ) are constantly connected to each other. A first element (SO 1 ) of the first planetary gear set (RS 1 ) forms the fourth shaft ( 4 ), a third element (HO 3 ) of the third planetary gear set (RS 3 ) forms the fifth shaft ( 5 ). As the sixth shaft ( 6 ), a third element (HO 1 ) of the first planetary gear set (RS 1 ), a second element (ST 2 ) of the second planetary gear set (RS 2 ) and a first element (SO 3 ) of the third planetary gear set (RS 3 ) are constantly connected. A first element (SO 2 ) of the second planetary gear set (RS 2 ) forms the seventh shaft ( 7 ). A first brake (B 1 ) is arranged in the power flow between the third shaft ( 3 ) and the housing (GG). A second brake (B 2 ) is arranged in the power flow between the fourth shaft ( 4 ) and the housing (GG). A third brake (B 3 ) is arranged in the power flow between the fifth shaft ( 5 ) and the housing (GG). A first clutch (C 1 ) is arranged in the power flow between the first and seventh shafts ( 1, 7 ). A second clutch (C 2 ) is arranged in the power flow between the first and third shafts ( 1, 3 ). A third clutch (C 3 ) is constantly connected to the eighth shaft ( 8 ). A fourth clutch is in the power flow between the first and fourth shafts ( 1, 4 ).

First claim

1 - 17 : (canceled)

18 . An automatic transmission for a motor vehicle, comprising:
a housing (GG); eight rotatable shafts ( 1 to 8 ) including one drive shaft (AN) and including one output shaft (AB); four individual planetary gear sets (RS 1 , RS 2 , RS 3 , RS 4 ), each of planetary gear sets further comprising a first element (SO 1 , SO 2 , SO 3 , SO 4 ), a second element (ST 1 , ST 2 , ST 3 , ST 4 ), and a third element (HO 1 , HO 2 , HO 3 , HO 4 ); seven shift elements (B 1 , B 2 , B 3 , C 1 , C 2 , C 3 , C 4 ), wherein selective engagement of the seven shift elements leads to the different transmission ratio relationships between the drive shaft (AN) and output shaft (AB) for shifting of several forward gears and one reverse gear, whereas three of the shift elements are designed as brakes (B 1 , B 2 , B 3 ) and four of the shift elements are designed as clutches (C 1 , C 2 , C 3 , C 4 ), and: the first shaft ( 1 ) is designed as the drive shaft (AN) of the transmission; the second element (ST 3 ) of the third planetary gear set (RS 3 ) forms the second shaft ( 2 ) as the output shaft (AB) of the transmission; the third shaft ( 3 ), the second element (ST 1 ) of the first planetary gear set (RS 1 ), and the third element (HO 2 ) of the second planetary gear set (RS 2 ) are constantly connected to each other; the first element (SO 1 ) of the first planetary gear set (RS 1 ) forms the fourth shaft ( 4 ), the third element (HO) of the third planetary gear set (RS 3 ) forms the fifth shaft ( 5 ), the third element (HO 1 ) of the first planetary gear set (RS 1 ) forms the sixth shaft ( 6 ) and is constantly connected to the first element (SO 3 ) of the third planetary gear set (RS 3 ); the first brake (B 1 ) is arranged in a power flow between the third shaft ( 3 ) and the housing (GG); the second brake (B 2 ) is arranged in a power flow between the fourth shaft ( 4 ) and the housing (GG); the third brake (B 3 ) is arranged in a power flow between the fifth shaft ( 5 ) and the housing (GG); the first clutch (C 1 ) is constantly connected to the seventh shaft ( 7 ); the second clutch (C 2 ) is arranged in a power flow between the first and third shafts ( 1 , 3 ); the fourth clutch is arranged in a power flow between the first and the fourth shafts ( 1 , 4 ); the second element (ST 2 ) of the second planetary gear set (RS 2 ) is constantly connected to the sixth shaft ( 6 ); the first element (SO 2 ) of the second planetary gear set (RS 2 ) forms the seventh shaft ( 7 ); the first clutch (C 1 ) is arranged in a power flow between the first and seventh shafts ( 1 , 7 ); and the third clutch (C 3 ) is constantly connected to the eighth shaft ( 8 ).

19 . The automatic transmission according to claim 18 , wherein:
the first element (SO 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the sixth shaft ( 6 ); the second element (ST 4 ) of the fourth planetary gear set (RS 4 ) forms the eighth shaft ( 8 ); the third element (HO 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the second shaft ( 2 ); and the third clutch (C 3 ) is arranged in a power flow between the first and eighth shafts ( 1 , 8 ).

20 . The automatic transmission according to claim 18 , wherein:
the first element (SO 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the sixth shaft ( 6 ); the third element (HO 4 ) of the fourth planetary gear set (RS 4 ) forms the eighth shaft ( 8 ); the second element (ST 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the first shaft ( 1 ); and the third clutch (C 3 ) is connected in a power flow between the second and eighth shafts ( 2 , 8 ).

21 . The automatic transmission according to claim 18 , wherein:
the first element (SO 4 ) of the fourth planetary gear set (RS 4 ) forms the eighth shaft ( 8 ); the second element (ST 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the first shaft ( 1 ); the third element (HO 4 ) of the fourth planetary gear set (RS 4 ) is constantly connected to the second shaft ( 2 ); and the third clutch (C 3 ) is connected in the power flow between the sixth and eighth shafts ( 6 , 8 ).

22 . The automatic transmission according to claim 18 , wherein, for each of the forward gears and the reverse gear, three of the shift elements are engaged and upon a change from a respective gear to a subsequent higher or lower gear, only one of the previously engaged shift elements is open and only one previously open shift element is engaged.

23 . The automatic transmission according to claim 22 , wherein the forward gears comprise eleven forward gears, and:
in the first forward gear, the first brake (B 1 ), the third brake (B 3 ) and the first clutch (C 1 ) transfer torque; in the second forward gear, the second brake (B 2 ), the third brake (B 3 ) and the first clutch (C 1 ) transfer torque; in the third forward gear, the third brake (B 3 ), the first clutch (C 1 ) and the second clutch (C 2 ) transfer torque; in the fourth forward gear, the second brake (B 2 ), the third brake (B 3 ) and the second clutch (C 2 ) transfer torque; in the fifth forward gear, the third brake (B 3 ), the second clutch (C 2 ) and the third clutch (C 3 ) transfer torque; in the sixth forward gear, the second brake (B 2 ), the second clutch (C 2 ) and the third clutch (C 3 ) transfer torque; in the seventh forward gear, the first clutch (C 1 ), the second clutch (C 2 ) and the third clutch (C 3 ) transfer torque; in the eighth forward gear, the second brake (B 2 ), the first clutch (C 1 ) and the third clutch (C 3 ) transfer torque; in the ninth forward gear, the first brake (B 1 ), the first clutch (C 1 ) and the third clutch (C 3 ) transfer torque; in the tenth forward gear, the first brake (B 1 ), the second brake (B 2 ) and the third clutch (C 3 ) transfer torque; in the eleventh forward gear, the first brake (B 1 ), the third clutch (C 3 ) and the fourth clutch (C 4 ) transfer torque; and in the reverse gear, the first brake (B 1 ), the third brake (B 3 ) and the fourth clutch (C 4 ) transfer torque.

24 . The automatic transmission according to claim 18 , wherein all four planetary gear sets (RS 1 , RS 2 , RS 3 , RS 4 ) are formed as negative planetary gear sets.

25 . The automatic transmission according to claim 18 , wherein one of the four planetary gear sets (RS 1 , RS 2 , RS 3 , RS 4 ) is formed as a positive planetary gear set, while each of the other three planetary gear sets is formed as a negative planetary gear set.

26 . The automatic transmission according to claim 18 , two of the four planetary gear sets are formed as a positive planetary gear sets and each of the other two planetary gear sets is formed as a negative planetary gear set.

27 . The automatic transmission according to claim 18 , wherein one of the four planetary gear sets is formed as a negative planetary gear set, while each of the other three planetary gear sets is formed as positive planetary gear set.

28 . The automatic transmission according to claim 18 , wherein all four planetary gear sets are formed as positive planetary gear sets.

29 . The automatic transmission according to claim 24 , wherein the four planetary gear sets are any combination of negative and positive planetary gear sets, and:
the first element of each negative planetary gear set and the first element of each positive planetary gear set is formed as a sun gear, the second element of each negative planetary gear set is formed as a planetary gear carrier, while the second element of each positive planetary gear set is formed a

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Beck Stefan
• Sibla Christian

Classifications

• F16H2200/2012

  with four sets of orbital gears · CPC title

• F16H2200/0073

  the gear ratios comprising eleven forward speeds · CPC title

• F16H3/66 Primary

  composed of a number of gear trains without drive passing from one train to another · CPC title

• F16H2200/2048

  with seven engaging means · CPC title