Multi-speed transmission

Abstract

A transmission includes an input and output member, four planetary gear sets each having first, second and third members, five interconnecting members continuously interconnecting members of the four planetary gear sets and six torque transmitting mechanisms selectively engageable to interconnect one of the first members, second members, and third members with at least one of another of the first members, second members, third members, and a stationary member. The torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.

What is claimed is: 
     
         1 . A transmission comprising:
 an input member;   an output member;   first, second, third and fourth planetary gear sets each having first, second and third members;   four interconnecting members, and wherein each of the four interconnecting members continuously interconnect one of the first, second, and third members of the first, second, third, and fourth planetary gear sets with at least one other of the first, second, and third members of the first, second, third and fourth planetary gear sets;   six torque transmitting mechanisms, and wherein each of the six torque transmitting mechanisms are selectively engageable to interconnect one of the first, second, and third members of the first, second, third, and fourth planetary gear sets with at least one of the input member and stationary member, and   wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.   
     
     
         2 . The transmission of  claim 1  wherein a first interconnecting member of the four interconnecting members continuously interconnects the second member of the first planetary gear set with the third member of the second planetary gear set. 
     
     
         3 . The transmission of  claim 2  wherein a second interconnecting member of the four interconnecting members continuously interconnects the third member of the first planetary gear set with the second member of the second planetary gear set and the first member of the fourth planetary gear set. 
     
     
         4 . The transmission of  claim 3  wherein a third interconnecting member of the four interconnecting members continuously interconnects the second member of the third planetary gear set with the third member of the fourth planetary gear set. 
     
     
         5 . The transmission of  claim 4  wherein a fourth interconnecting member of the four interconnecting members continuously interconnects the third member of the third planetary gear set with the second member of the fourth planetary gear set. 
     
     
         6 . The transmission of  claim 1  wherein a first of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the first planetary gear set with the stationary member. 
     
     
         7 . The transmission of  claim 6  wherein a second of the six torque transmitting mechanisms is selectively engageable to interconnect at least one of the second member of the third planetary gear set and the third member of the fourth planetary gear set with the stationary member. 
     
     
         8 . The transmission of  claim 7  wherein a third of the six torque transmitting mechanisms is selectively engageable to interconnect at least one of the second member of the first planetary gear set and the third member of the second planetary gear set with the input member. 
     
     
         9 . The transmission of  claim 8  wherein a fourth of the six torque transmitting mechanisms is selectively engageable to interconnect at least one of the second member of the fourth planetary gear set and the third member of the third planetary gear set with the stationary member. 
     
     
         10 . The transmission of  claim 9  wherein a fifth of the six torque transmitting mechanisms is selectively engageable to interconnect at least one of the second member of the third planetary gear set and the third member of the fourth planetary gear set with the input member. 
     
     
         11 . The transmission of  claim 10  wherein a sixth of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the second planetary gear set with the stationary member. 
     
     
         12 . The transmission of  claim 10  wherein a sixth of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the third planetary gear set with the stationary member. 
     
     
         13 . The transmission of  claim 1  wherein the output member is continuously connected to at least one of the first member of the second planetary gear set and the first member of the third planetary gear set. 
     
     
         14 . The transmission of  claim 1  wherein the first and second planetary gear sets are arranged and combined as a stacked planetary gear set having a sun gear, a ring gear, a planet carrier member, a first and second set of pinions, and a combination gear, the first set of pinions are rotatably supported by the planet carrier member and intermesh with the sun gear and the combination gear, and the second set of pinions are rotatably supported by the planet carrier member and intermesh with the ring gear and combination gear. 
     
     
         15 . A transmission comprising:
 an input member;   an output member;   first, second, third and fourth planetary gear sets each having first, second and third members, and wherein the output member is continuously connected to at least one of the first member of the second planetary gear set and the first member of the third planetary gear set;   a first interconnecting member continuously interconnecting the second member of the first planetary gear set with the third member of the second planetary gear set;   a second interconnecting member continuously interconnecting the third member of the first planetary gear set with the second member of the second planetary gear set and the first member of the fourth planetary gear set;   a third interconnecting member continuously interconnecting the second member of the third planetary gear set with the third member of the fourth planetary gear set;   a fourth interconnecting member continuously interconnecting the third member of the third planetary gear set with the second member of the fourth planetary gear set;   six torque transmitting mechanisms, and wherein each of the six torque transmitting mechanisms are selectively engageable to interconnect at least one of the first, second, and third members of the first, second, third, and fourth planetary gear sets and the first, second, third, and fourth interconnecting members with at least one of the input member and stationary member, and   wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.   
     
     
         16 . The transmission of  claim 15  wherein a first of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the first planetary gear set with the stationary member. 
     
     
         17 . The transmission of  claim 16  wherein a second of the six torque transmitting mechanisms is selectively engageable to interconnect the third interconnecting member with the stationary member. 
     
     
         18 . The transmission of  claim 17  wherein a third of the six torque transmitting mechanisms is selectively engageable to interconnect the first interconnecting member with the input member. 
     
     
         19 . The transmission of  claim 18  wherein a fourth of the six torque transmitting mechanisms is selectively engageable to interconnect fourth interconnecting member with the stationary member. 
     
     
         20 . The transmission of  claim 19  wherein a fifth of the six torque transmitting mechanisms is selectively engageable to interconnect third interconnecting member with the input member. 
     
     
         21 . The transmission of  claim 20  wherein a sixth of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the second planetary gear set with the stationary member. 
     
     
         22 . The transmission of  claim 20  wherein a sixth of the six torque transmitting mechanisms is selectively engageable to interconnect the first member of the third planetary gear set with the stationary member. 
     
     
         24 . The transmission of  claim 1  wherein the first and second planetary gear sets are arranged and combined as a stacked planetary gear set having a sun gear, a ring gear, a planet carrier member, a first and second set of pinions, and a combination gear, the first set of pinions are rotatably supported by the planet carrier member and intermesh with the sun gear and the combination gear, and the second set of pinions are rotatably supported by the planet carrier member and intermesh with the ring gear and combination gear. 
     
     
         25 . A transmission comprising:
 an input member;   an output member;   first, second, third and fourth planetary gear sets each having first, second and third members, and wherein the output member is continuously connected to at least one of the first member of the second planetary gear set and the first member of the third planetary gear set;   four interconnecting members, and wherein each of the four interconnecting members continuously interconnect one of the first, second, and third members of the first, second, third, and fourth planetary gear sets with at least one other of the first, second, and third members of the first, second, third and fourth planetary gear sets;   a first torque transmitting mechanism selectively engageable to interconnect the first member of the first planetary gear set a the stationary member;   a second torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the third planetary gear set and the third member of the fourth planetary gear set with the stationary member;   a third torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the first planetary gear set and the third member of the second planetary gear set with the input member;   a fourth torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the fourth planetary gear set and the third member of the third planetary gear set with the stationary member;   a fifth torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the third planetary gear set and the third member of the fourth planetary gear set with the input member;   a sixth torque transmitting mechanism selectively engageable to interconnect one of the first members of the second and third planetary gear sets with the stationary member; and   wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.   
     
     
         26 . The transmission of  claim 25  wherein a first interconnecting member of the four interconnecting members continuously interconnects the second member of the first planetary gear set with the third member of the second planetary gear set. 
     
     
         27 . The transmission of  claim 26  wherein a second interconnecting member of the four interconnecting members continuously interconnects the third member of the first planetary gear set with the second member of the second planetary gear set and the first member of the fourth planetary gear set. 
     
     
         28 . The transmission of  claim 27  wherein a third interconnecting member of the four interconnecting members continuously interconnects the second member of the third planetary gear set with the third member of the fourth planetary gear set. 
     
     
         29 . The transmission of  claim 28  wherein a fourth interconnecting member of the four interconnecting members continuously interconnects the third member of the third planetary gear set with the second member of the fourth planetary gear set. 
     
     
         30 . The transmission of  claim 25  wherein the first and second planetary gear sets are arranged and combined as a stacked planetary gear set having a sun gear, a ring gear, a planet carrier member, a first and second set of pinions, and a combination gear, the first set of pinions are rotatably supported by the planet carrier member and intermesh with the sun gear and the combination gear, and the second set of pinions are rotatably supported by the planet carrier member and intermesh with the ring gear and combination gear.