Clutch and gear arrangement for a front wheel drive vehicle

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.

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.

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.

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.

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.

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.