Multi step transmission

• US 8,246,504 B2
• Filed: 08/19/2010
• Issued: 08/21/2012
• Est. Priority Date: 08/20/2009
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Gumpoltsberger, Gerhard, Sibla, Christian, Beck, Stefan, Haupt, Josef, Bauknecht, Gert, Ziemer, Peter
• Primary Examiner(s): Le, David D
• Assistant Examiner(s): Fluhart, Stacey
• Application Number:
  US12/859,409
• Publication Number:
  US 20110045942A1
• Time in Patent Office: 733 Days
• Field of Search: 475/269, 475/275, 475/278, 475/284, 475/296
• US Class Current: 475/286
• CPC Class Codes: F16H 2200/0065 the gear ratios comprising nine forward speeds
• CPC Class Codes: F16H 2200/2012 with four sets of orbital gears
• CPC Class Codes: F16H 2200/2046 with six engaging means
• CPC Class Codes: F16H 2200/2097 comprising an orbital gear set member permanently connected to the housing, e.g. a sun wheel permanently connected to the housing
• CPC Class Codes: F16H 3/66 composed of a number of gear trains without drive passing from one train to another

Abstract

The multi step transmission comprising gear sets (P1, P2, P3, P4), eight shafts and six shift elements. The sun gear of set (P1) couples the drive shaft, the carrier of set (P1) couples shaft (3) which couples a housing via brake (03), the drive shaft via clutch (13) and shaft (5) via clutch (35). Shaft (5) couples the ring gear of set (P2), to the sun gears of sets (P3, P4), and the drive shaft couples, via clutch (18), shaft (8) that couples the carrier of set (P4). Shaft (6) couples the ring gear of set (P1) and, via clutch (67), shaft (7) that couples the carrier of set (P2). The sun gear of set (P2) couples the housing. The ring gear of set (P3) couples shaft (4) that couples the housing via brake (04). The output shaft couples the ring gear and carrier of sets (P4, P3) respectively.

Claims

1. A multi step transmission of a planetary design for an automatic transmission for a motor vehicle, the multi-step transmission comprising:

a drive shaft (1);

an output shaft (2);

first, second, third and fourth planetary gear sets (P1, P2, P3, P4) which are disposed in a housing (G); and

a rotatable third shaft (3), a rotatable fourth shaft (4), a rotatable fifth shaft (5), a rotatable sixth shaft (6), a rotatable seventh shaft (7) and a rotatable eighth shaft (8) and at least six shift elements (03, 04, 13, 18, 35, 36, 67), comprising first and second brakes (03, 04) and first, second, third and fourth clutches (13, 18, 35, 36, 67) whose selected engagement produces different transmission ratios between the drive shaft (1) and the output shaft (2) so that nine forward gears and a reverse gear can be achieved;

wherein a sun gear of the first planetary gear set (P1) is connected to the drive shaft (1);

a carrier of the first planetary gear set (P1) is directly connected to the third shaft (3) which is connectable to the housing (G) of the transmission, via the first brake (03);

the third shaft (3) is directly connected to the second clutch (35), and the second clutch (35) is directly connected to the fifth shaft (5) so that third shaft (3) is detachably connectable, via the second clutch (35), to the fifth shaft (5);

the fifth shaft (5) is directly connected to a ring gear of the second planetary gear set (P2), to a sun gear of the third planetary gear set (P3) and to a sun gear of the fourth planetary gear set (P4);

the drive shaft (1) is detachably connectable, via the third clutch (18), to the eighth shaft (8) that is connected a carrier of the fourth planetary gear set (P4);

the sixth shaft (6) is connected to a ring gear of the first planetary gear set (P1) and is detachably connectable, via the fourth clutch (67), to the seventh shaft (7) that is connected to a carrier of the second planetary gear set (P2);

a sun gear of the second planetary gear set (P2) is coupled to the housing (G) of the transmission;

a ring gear of the third planetary gear set (P3) is connected to the fourth shaft (4) which is connectable to the housing (G) of the transmission, via the second brake (04);

the output shaft (2) is connected to a ring gear of the fourth planetary gear set (P4) and to a carrier of the third planetary gear set (P3), and

the first planetary gear set (P1) can be locked by engagement of the first clutch (13 or 36) such that, when locked, the sun gear, the planet carrier and the ring gear of the first planetary gear set (P1) all rotate together in unison with one another.

2. The multi step transmission according to claim 1, wherein the first, the second, the third and the fourth planetary gear sets (P1, P2, P3, P4) are minus planetary gear sets.

3. The multi step transmission according to claim 1, wherein the first clutch (13 or 36) one of detachably connects the third shaft (3) to the drive shaft (1), and

detachably connects the third shaft (3) to the sixth shaft (6).

4. The multi step transmission according to claim 3, wherein a first forward gear is attained by engagement of the second brake (04) and the second and fourth clutch (35, 67);

a second forward gear is attained by engagement of the second brake (04) and the first and the second clutches (13 or 36, 35);

a third forward gear is attained by engagement of the second brake (04) and the first and the fourth clutch (13 or 36, 67);

a fifth forward gear is attained by engagement of the first, the third and the fourth clutch (13 or 36, 18, 67);

a sixth forward gear is attained by engagement of the first, the second and the third clutched (13 or 36, 35, 18);

a seventh forward gear is attained by engagement of the second, the third and the fourth clutches (35, 18, 67);

an eighth forward gear is attained by engagement of the first brake (03) and the second and the third clutches (35, 18),

a ninth forward gear is attained by engagement of the first brake (03) and the third and the fourth clutched (18, 67),

the reverse gear is attained by engagement of the first and the second brakes (03, 04) and the fourth clutch (67),

when the first clutch (13) detachably connects the third shaft (3) to the drive shaft (1), a fourth forward gear is attained by engagement of the second brake (04) and the third and the fourth clutches (18, 67), and

when the first clutch (36) detachably connects the third shaft (3) to the sixth shaft (6), the fourth forward gear is attained by engagement of the second brake (04) and the first and the third clutches (36, 18).