Patent Abstract:
A front wheel drive transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear member, a planet carrier member, and a ring gear member. The torque transmitting devices include clutches and brakes arranged within a transmission housing. Each of the clutches and brakes are located within specific areas defined by the planetary gear sets and the housing walls.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/444,064 filed on Feb. 17, 2011. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The invention relates generally to a multiple speed transmission having a plurality of planetary gear sets and a plurality of torque transmitting devices and more particularly to a transmission configured for a front wheel drive vehicle having nine or more speeds, six torque transmitting devices, and four planetary gear sets. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art. 
     A typical multiple speed transmission uses a combination of a plurality of torque transmitting mechanisms, planetary gear arrangements and fixed interconnections to achieve a plurality of gear ratios. The number and physical arrangement of the planetary gear sets, generally, are dictated by packaging, cost and desired speed ratios. 
     While current transmissions achieve their intended purpose, the need for new and improved transmission configurations which exhibit improved performance, especially from the standpoints of efficiency, responsiveness and smoothness and improved packaging, primarily reduced size and weight, is essentially constant. Accordingly, there is a need for an improved, cost-effective, compact multiple speed transmission. 
     SUMMARY 
     In one aspect of the present invention, a transaxle is provided having transmission input member, a transmission output member, a plurality of planetary gear sets, and a plurality of torque-transmitting mechanisms. 
     In another aspect of the present invention, the transmission includes a housing having a first wall, a second wall, and a third wall extending between the first and second walls. First, second, third and fourth planetary gear sets are disposed within the housing. Each planetary gear set includes a sun gear member, a ring gear member, and a planet carrier member supporting a plurality of planet gears each configured to intermesh with both the sun gear member and the ring gear member. 
     In another aspect of the present invention, the torque-transmitting mechanisms are disposed within a plurality of areas or zones. The zones are defined by the transmission housing and the planetary gear sets. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1A  is a schematic diagram of a gear arrangement for a front wheel drive transmission according to the principles of the present invention; 
         FIG. 1B  is a chart showing the locations of the torque transmitting devices for the arrangement of planetary gear sets of the transmission shown in  FIG. 1A , in accordance with the embodiments of the present invention; 
         FIG. 2A  is another schematic diagram of a gear arrangement for a front wheel drive transmission according to the principles of the present invention; 
         FIG. 2B  is a chart showing the locations of the torque transmitting devices for the arrangement of planetary gear sets of the transmission shown in  FIG. 2A , in accordance with the embodiments of the present invention; 
         FIG. 3A  is another schematic diagram of a gear arrangement for a front wheel drive transmission according to the principles of the present invention; 
         FIG. 3B  is a chart showing the locations of the torque transmitting devices for the arrangement of planetary gear sets of the transmission shown in  FIG. 3A , in accordance with the embodiments of the present invention, 
         FIG. 4A  is another schematic diagram of a gear arrangement for a front wheel drive transmission according to the principles of the present invention; and 
         FIG. 4B  is a chart showing the locations of the torque transmitting devices for the arrangement of planetary gear sets of the transmission shown in  FIG. 4A , in accordance with the embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
     Referring now to  FIG. 1A , an embodiment of a front wheel drive multi-speed or nine speed transmission is generally indicated by reference number  10 . The transmission  10  is illustrated as a front wheel drive or transverse transmission, though various other types of transmission configurations may be employed. The transmission  10  includes a transmission housing  12 , an input shaft or member  14 , an output shaft or member  16  and a gear arrangement  18 . The input member  14  is continuously connected to an engine (not shown) or to a turbine of a torque converter (not shown). The output member  16  is continuously connected with a final drive unit (not shown) or transfer case (not shown). 
     The gear arrangement  18  of transmission  10  includes a first planetary gear set  20 , a second planetary gear set  22 , a third planetary gear set  24 , and a fourth planetary gear set  26 . The planetary gear sets  20 ,  22 ,  24  and  26  are connected between the input member  14  and the output member  16 . 
     In an embodiment of the present invention, the first planetary gear set  20  includes a sun gear member  20 A, a planet gear carrier member  20 C and a ring gear member  20 B. The sun gear member  20 A is connected for common rotation with a first shaft or interconnecting member  42 . The ring gear member  20 B is connected for common rotation with a second shaft or interconnecting member  44 . The planet gear carrier member  20 C rotatably supports a set of planet gears  20 D (only one of which is shown) and is connected for common rotation with a third shaft or interconnecting member  46  and a fourth shaft or interconnecting member  48 . The planet gears  20 D are each configured to intermesh with both the sun gear member  20 A and the ring gear member  20 B. 
     The second planetary gear set  22  includes a sun gear member  22 A, a planet carrier member  22 C that rotatably supports a set of planet gears  22 D and  22 E, and a ring gear member  22 B. The sun gear member  22 A is connected for common rotation with the input member  14 . The ring gear member  22 B is connected for common rotation with the second shaft or interconnecting member  44 . It should be appreciated that the ring gear member  22 B and the ring gear member  22 A may be combined into a single long ring gear without departing from the scope of the present invention. The planet carrier member  22 C is connected for common rotation with the fourth shaft or interconnecting member  48  and a fifth shaft or interconnecting member  50 . The planet gears  22 D are each configured to intermesh with both the ring gear member  22 B and the planet gears  22 E. The planet gears  22 E are each configured to intermesh with both the planet gears  22 D and the sun gear  22 A. 
     The third planetary gear set  24  includes a sun gear member  24 A, a ring gear member  24 B and a planet carrier member  24 C that rotatably supports a set of planet gears  24 D. The sun gear member  24 A is connected for common rotation with the fifth interconnecting member  50 . The ring gear member  24 B is connected for common rotation with a sixth shaft or interconnecting member  52  and the output member  16 . The planet carrier member  24 C is connected for common rotation with a seventh shaft or interconnecting member  54  and with an eighth shaft or interconnecting member  56 . The planet gears  24 D are each configured to intermesh with both the sun gear member  24 A and the ring gear member  24 B. 
     The fourth planetary gear set  26  includes a sun gear member  26 A, a ring gear member  26 C and a planet carrier member  26 B that rotatably supports a set of planet gears  26 D. The sun gear member  26 A is connected for common rotation with a ninth shaft or interconnecting member  58 . The ring gear member  26 C is connected for common rotation with the seventh interconnecting member  54 . The planet carrier member  26 B is connected for common rotation with the sixth interconnecting member  52  and with the output member  16 . The planet gears  26 D are each configured to intermesh with both the sun gear member  26 A and the ring gear member  26 C. 
     The input shaft or member  14  is preferably continuously connected to an engine (not shown) or to a turbine of a torque converter (not shown). The output shaft or member  16  is preferably continuously connected with the final drive unit or transfer case (not shown). 
     The torque-transmitting mechanisms or clutches  66 ,  68  and brakes  70 ,  72 ,  74 ,  76  allow for selective interconnection of the shafts or interconnecting members, members of the planetary gear sets and the housing. For example, the first clutch  66  is selectively engageable to connect the seventh interconnecting member  54  with the input member  14 . The second clutch  68  is selectively engageable to connect the ninth interconnecting member  58  with the input member  14 . The first brake  70  is selectively engageable to connect the first interconnecting member  42  to the stationary member or transmission housing  40  in order to restrict the sun gear member  20 A of the first planetary gear set  20  from rotating relative to the stationary member or transmission housing  40 . The second brake  72  is selectively engageable to connect the second interconnecting member  44  to the stationary member or transmission housing  40  in order to restrict the ring gear member  20 B of the first planetary gear set  20  and the ring gear member  22 B of the second planetary gear set  22  from rotating relative to the stationary member or transmission housing  40 . The third brake  74  is selectively engageable to connect the third interconnecting member  46  to the stationary member or transmission housing  40  in order to restrict the planet carrier member  20 C of the first planetary gear set  20 , the planet carrier member  22 C of the second planetary gear set  22 , and the sun gear  24 A of the third planetary gear set  24  from rotating relative to the stationary member or transmission housing  40 . The fourth brake  76  is selectively engageable to connect the eighth interconnecting member  56  to the stationary member or transmission housing  40  in order to restrict the planet carrier member  24 C of the third planetary gear set  24  and the ring gear member  26 C of the fourth planetary gear set  26  from rotating relative to the stationary element or transmission housing  40 . 
     The transmission  10  is capable of transmitting torque from the input shaft or member  14  to the output shaft or member  16  in at least nine forward torque ratios and one reverse torque ratio. Each of the forward torque ratios and the reverse torque ratio are attained by engagement of one or more of the torque-transmitting mechanisms (i.e. first clutch  66 , second clutch  68 , first brake  70 , second brake  72 , third brake  74 , and fourth brake  76 ). Those skilled in the art will readily understand that a different speed ratio is associated with each torque ratio. Thus, nine forward speed ratios may be attained by the transmission  10 . 
     The transmission housing  12  includes a first wall or structural member  102 , a second wall or structural member  104  and a third wall or structural member  106 . The first wall  102  interconnects the second and third walls  104  and  106  to define a space or cavity  108 . Both the input and output shafts  14 ,  16  exit the transmission  10  via the second wall  104 . The planetary gear sets  20 ,  22 ,  24  and  26  and the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  are disposed within cavity  108 . Further, the cavity  108  has a plurality of areas or zones A, B, C, D, E, and F in which the plurality of torque transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  will be specifically positioned or mounted, in accordance with the preferred embodiments of the present invention. 
     As shown in  FIG. 1A , zone A is defined by the area or space bounded by: the first wall  102 , planetary gear set  20 , radially inward by a reference line “L” which is a longitudinal line that is axially aligned with the input shaft  14 , and radially outward by a reference line “M” which is a longitudinal line that extends adjacent an outer diameter or outer periphery of the planetary gear sets  20 ,  22 ,  24  and  26 . While reference line “M” is illustrated as a straight line throughout the several views, it should be appreciated that reference line “M” follows the outer periphery of the planetary gear sets  20 ,  22 ,  24  and  26 , and accordingly may be stepped or non-linear depending on the location of the outer periphery of each of the planetary gear sets  20 ,  22 ,  24  and  26 . Zone B is defined by the area bounded by: planetary gear set  20 , the planetary gear set  22 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone C is defined by the area bounded by: the planetary gear set  22 , the planetary gear set  24 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone D is defined by the area bounded by: the planetary gear set  24 , the planetary gear set  26 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone E is defined by the area bounded by: the planetary gear set  26 , the second end wall  104 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone F is defined by the area bounded by: the fist wall  102 , the second wall  104 , radially inward by reference line “M” and radially outward by the third wall  106 . 
     In the gear arrangement  18  of transmission  10  shown in  FIG. 1A , the planetary gear set  20  is disposed closest to the fist wall  102 , the planetary gear set  26  is disposed closest to the second wall  104 , the planetary gear set  22  is disposed adjacent the planetary gear set  20 , and the planetary gear set  24  is disposed between the planetary gear sets  22  and  26 . The torque-transmitting mechanisms are intentionally located within specific Zones in order to provide advantages in overall transmission size, packaging efficiency, and reduced manufacturing complexity. In the particular example shown in  FIG. 1A , the first clutch  66  and the second clutch  68  are located in Zone E and the first brake  70 , the second brake  72 , the third brake  74 , and the fourth brake  76  are all disposed within Zone F. 
     However, the present invention contemplates other embodiments where the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  are disposed in the other Zones. The feasible locations of the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  within the Zones are illustrated in the chart shown in  FIG. 1B . The chart of  FIG. 1B  lists clutches and brakes in the left most column and the available Zones to locate the clutch/brake in the top row. An “X” in the chart indicates that the present invention contemplates locating the clutch or brake in the Zone listed in the top row. For example, first clutch  66  may be located in Zones C, D, or E. 
     Referring now to  FIG. 2A , another embodiment of a transmission is generally indicated by reference number  100 . The transmission  100  is similar to transmission  10  and like components are indicated by like reference numbers. However, as shown in  FIG. 2A , member  56  has extended to connect directly with the ring gear member  26 C of the fourth planetary gear set  26  and member  54  no longer directly connects with the ring gear member  26 C of the fourth planetary gear set  26 . 
     The torque-transmitting mechanisms are intentionally located within specific Zones in order to provide advantages in overall transmission size, packaging efficiency, and reduced manufacturing complexity. In the particular example shown in  FIG. 2A , the first clutch  66  and the second clutch  68  are located in Zone E and the first brake  70 , the second brake  72 , the third brake  74 , and the fourth brake  76  are all disposed within Zone F. 
     However, the present invention contemplates other embodiments where the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74  and  76  are disposed in the other Zones. The feasible locations of the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  within the Zones are illustrated in the chart shown in  FIG. 2B . The chart of  FIG. 2B  lists clutches and brakes in the left most column and the available Zones to locate the clutch/brake in the top row. An “X” in the chart indicates that the present invention contemplates locating the clutch or brake in the zone listed in the top row. For example, the first clutch  66  may be located in Zones C, D, or E. 
     Referring now to  FIG. 3A , another embodiment of a transmission is generally indicated by reference number  200 . The transmission  200  is similar to transmission  10  and like components are indicated by like reference numbers. However, as shown in  FIG. 3A , Zone A is defined by the area or space bounded by: the first wall  102 , planetary gear set  22 , radially inward by a reference line “L” which is a longitudinal line that is axially aligned with the input shaft  14 , and radially outward by a reference line “M” which is a longitudinal line that extends adjacent an outer diameter or outer periphery of the planetary gear sets  20 ,  22 ,  24  and  26 . While reference line “M” is illustrated as a straight line throughout the several views, it should be appreciated that reference line “M” follows the outer periphery of the planetary gear sets  20 ,  22 ,  24  and  26 , and accordingly may be stepped or non-linear depending on the location of the outer periphery of each of the planetary gear sets  20 ,  22 ,  24  and  26 . Zone B is defined by the area bounded by: planetary gear set  22 , the planetary gear set  20 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone C is defined by the area bounded by: the planetary gear set  20 , the planetary gear set  24 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone D is defined by the area bounded by: the planetary gear set  24 , the planetary gear set  26 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone E is defined by the area bounded by: the planetary gear set  26 , the second end wall  104 , radially outward by reference line “M”, and radially inward by reference line “L”. Zone F is defined by the area bounded by: the first wall  102 , the second wall  104 , radially inward by reference line “M” and radially outward by the third wall  106 . 
     In the gear arrangement  218  of transmission  200  shown in  FIG. 3A , the planetary gear set  22  is disposed closest to the first wall  102 , the planetary gear set  26  is disposed closest to the second wall  104 , the planetary gear set  20  is adjacent the planetary gear set  22 , and the planetary gear set  24  is disposed between the planetary gear sets  20  and  26 . The torque-transmitting mechanisms are intentionally located within specific Zones in order to provide advantages in overall transmission size, packaging efficiency, and reduced manufacturing complexity. In the particular example shown in  FIG. 4A , the first clutch  66  and the second clutch  68  are located in Zone E and the first brake  70 , the second brake  72 , the third brake  74 , and the fourth brake  76  are all disposed within Zone F. 
     However, the present invention contemplates other embodiments where the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  are disposed in the other Zones. The feasible locations of the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  within the Zones are illustrated in the chart shown in  FIG. 3B . The chart of  FIG. 3B  lists clutches and brakes in the left most column and the available zones to locate the clutch/brake in the top row. An “X” in the chart indicates that the present invention contemplates locating the clutch or brake in the zone listed in the top row. For example, the first brake  66  may be located in Zones C, D, or E. 
     Referring now to  FIG. 4A , another embodiment of a transmission is generally indicated by reference number  300 . The transmission  300  is similar to transmission  200  and like components are indicated by like reference numbers. However, as shown in  FIG. 4A , member  56  has extended to connect directly with the ring gear member  26 C of the fourth planetary gear set  26  and member  54  no longer directly connects with the ring gear member  26 C of the fourth planetary gear set  26 . 
     The torque-transmitting mechanisms are intentionally located within specific Zones in order to provide advantages in overall transmission size, packaging efficiency, and reduced manufacturing complexity. In the particular example shown in  FIG. 4A , the first clutch  66  and the second clutch  68  are located in Zone E and the first brake  70 , the second brake  72 , the third brake  74 , and the fourth brake  76  are all disposed within Zone F. 
     However, the present invention contemplates other embodiments where the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74  and  76  are disposed in the other Zones. The feasible locations of the torque-transmitting mechanisms  66 ,  68 ,  70 ,  72 ,  74 , and  76  within the Zones are illustrated in the chart shown in  FIG. 4B . The chart of  FIG. 4B  lists clutches and brakes in the left most column and the available Zones to locate the clutch/brake in the top row. An “X” in the chart indicates that the present invention contemplates locating the clutch or brake in the zone listed in the top row. For example, the first clutch  66  may be located in Zones C, D, or E. 
     The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Technology Classification (CPC): 5