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Method for controlling a multi-speed transmission having four planetary gear sets for producing at least nine gear speeds

  • US 8,961,355 B2
  • Filed: 07/21/2011
  • Issued: 02/24/2015
  • Est. Priority Date: 07/21/2011
  • Status: Active Grant
First Claim
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1. A method for controlling a transmission, the method comprising:

  • providing an input member;

    providing an output member;

    providing first, second, third and fourth planetary gear sets each having first, second and third members;

    providing a first interconnecting member for continuously interconnecting the third member of the first planetary gear set with first members of the third and fourth planetary gear sets;

    providing a second interconnecting member for continuously interconnecting the second member of the first planetary gear set with the third member of the second planetary gear set;

    providing a third interconnecting member for continuously interconnecting the first member of the second planetary gear set and the input member with the second member of the fourth planetary gear set;

    providing a first torque transmitting device to selectively interconnect the input member, the first member of the second planetary gear set and second member of the fourth planetary gear set with the second member of the second planetary gear set;

    providing a second torque transmitting device to selectively interconnect the second member of the second planetary gear set with the third member of the first planetary gear set and the first members of the third and fourth planetary gear sets;

    providing a third torque transmitting device to selectively interconnect the second member of the third planetary gear set and the output member with the third member of the fourth planetary gear set;

    providing a fourth torque transmitting device to selectively interconnect the second member of the second planetary gear set with a stationary member;

    providing a fifth torque transmitting device to selectively interconnect the first member of the first planetary gear set with the stationary member;

    providing a sixth torque transmitting device to selectively interconnect the third member of the third planetary gear set with the stationary member;

    establishing a first forward speed ratio by selectively activating the second, the fifth and the sixth torque transmitting devices;

    establishing a second forward speed ratio by selectively activating the first, the second and the sixth torque transmitting devices;

    establishing a third forward speed ratio by selectively activating the first, the fifth and the sixth torque transmitting devices;

    establishing a fourth forward speed ratio by selectively activating the third, the fourth and the sixth torque transmitting device;

    establishing a fifth forward speed ratio by selectively activating the first, the third and the fifth torque transmitting devices;

    establishing a sixth forward speed ratio by selectively activating the first, the second and the third torque transmitting devices;

    establishing a seventh forward speed ratio by selectively activating the second, the third and the fifth torque transmitting devices;

    establishing an eighth forward speed ratio by selectively activating the second, the third and the fourth torque transmitting devices;

    establishing a ninth forward speed ratio by selectively activating the third, the fourth and the fifth torque transmitting devices; and

    establishing a reverse speed ratio by selectively activating the fourth, the fifth and the sixth torque transmitting devices.

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