Three-mode continuously variable transmission with a direct low mode and two split path high modes

• US 7,238,135 B2
• Filed: 06/03/2005
• Issued: 07/03/2007
• Est. Priority Date: 06/03/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Coffey, Dan, Sefcik, Michael C.
• Primary Examiner(s): Lewis; Tisha
• Application Number:
  US11/144,161
• Publication Number:
  US 20060276294A1
• Time in Patent Office: 760 Days
• Field of Search: 475210-213, 475/218, 475/219
• US Class Current: 475/210
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 37/0846 CVT using endless flexible members

Abstract

A powertrain includes a continuously variable transmission having a starting mechanism, a continuously variable unit (CVU), and a pair of planetary gear arrangements. The continuously variable transmission also includes a plurality of torque transmitting mechanisms which are selectively engageable in combinations of two to establish a reverse mode of operation between the starting mechanism and a transmission output shaft, a low direct mode of operation, an intermediate split mode of operation, and a high split mode of operation.

Claims

1. A powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes comprising:

input means for delivering power to said continuously variable transmission;

a transmission housing;

output means for delivering power from said continuously variable transmission;

a continuously variable unit having an input member continuously interconnected with said input means and an output member;

a first planetary gear arrangement having a first member continuously interconnected with said output member, a second member, and a third member;

a second planetary gear arrangement having a first member continuously interconnected with said second member of said first planetary gear arrangement, a second member continuously interconnected with said output means, and a third member;

a first torque transmitting mechanism for selectively interconnecting said third member of said second planetary gear arrangement with said transmission housing;

a second torque transmitting mechanism operable to interconnect two of said members of said first planetary gear arrangement;

a third torque transmitting mechanism operable to continuously interconnect said third member of said first planetary gear arrangement with said transmission housing;

a fourth torque transmitting mechanism operable to selectively interconnect said input means and said third member of said second planetary gear arrangement; and

said torque transmitting mechanisms being operable in combinations of two to establish three forward modes and one reverse mode between input means and said output means.

2. The powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes defined in claim 1 further comprising:

said continuously variable unit being varied from an underdrive condition to an overdrive condition during said three forward modes of operation.

3. The powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes defined in claim 1 further comprising:

said first torque transmitting mechanism including a two-way frictional torque transmitting mechanism and a one-way torque transmitting mechanism; and

said third torque transmitting mechanism including a two-way frictional torque transmitting mechanism and a one-way torque transmitting mechanism.

4. The powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes defined in claim 1 further comprising:

said input means including a mechanical power source; and

a starting mechanism disposed between said mechanical power source and said input member of said continuously variable unit.

5. The powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes defined in claim 4 further comprising:

said starting mechanism including a torque converter and a torque converter clutch; and

said fourth torque transmitting mechanism being connectable between said mechanical power source and said third member of said second planetary gear set in series drive relation with said torque converter clutch and in by passing relation with said torque converter of said starting mechanism.

6. The powertrain having a three-mode continuously variable transmission with a direct low mode and two split path high modes defined in claim 1 further comprising:

said first member of said first planetary gear arrangement being a sun gear member, said second member of said first planetary gear arrangement being a ring gear member, and said third member of said first planetary arrangement being a planet carrier assembly member; and

said first member of said second planetary gear arrangement being a sun gear member, said second member of said second planetary gear arrangement being a ring gear member, and said third member of said second planetary gear arrangement being a planet carrier assembly member.