Transmission

• US 20030119623A1
• Filed: 11/15/2002
• Published: 06/26/2003
• Est. Priority Date: 11/15/2001
• 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: Carey, Clinton E., Borgerson, James B., Dusenberry, Donald L., Maguire, Joel M., Wittkopp, Scott H., Stevenson, Paul D., Biallas, Jeffrey J., Kienzle, Kent H., Winship, Richard A.
• Granted Patent: US 6,827,664 B2
• Time in Patent Office: Days
• US Class Current: 475/275
• CPC Class Codes: F16H 2200/0052 the gear ratios comprising six forward speeds
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/201 with three sets of orbital gears
• CPC Class Codes: F16H 2200/2097 comprising an orbital gear set member permanently connected to the housing, e.g. a sun wheel permanently connected to the housing
• CPC Class Codes: F16H 3/66 composed of a number of gear trains without drive passing from one train to another
• CPC Class Codes: F16H 3/666 with compound planetary gear units, e.g. two intermeshing orbital gears F16H3/663 takes precedence

Abstract

A powertrain includes a power transmission having an input shaft continuously connected directly between an engine and a planetary gear member of a first planetary gearset. Another member of the planetary gearset is selectively grounded by a torque transmitting mechanism to establish a reaction member during the launch of a vehicle incorporating the powertrain. The reaction member is established during both the lowest forward drive ratio and the reverse drive ratio. A third member of the planetary gearset transmits the torque from the input shaft, as modified by the planetary gearset, to other planetary gearsets in down stream power flow arrangement with the first planetary gearset.

Claims

1. A power transmission for use in a powertrain having an engine for providing rotary power to the transmission, said transmission comprising:

an input shaft continuously connected with the engine for co-rotation therewith;

a first planetary gearset having a first member driven by said input shaft, a second member, and a third member;

a second planetary gearset having a first member driven by said second member of said first planetary gearset, a second member driving said output shaft, and a third member;

a third planetary gearset having a first member driven by said second member of said second planetary gearset, a second member and a third member;

a first torque transmitting mechanism that is operable to selectively engage said third member of said third planetary gearset for rotation with said input shaft;

a second torque transmitting mechanism that is selectively operable to engage said first member of said first planetary gearset for rotation with said input shaft;

a third torque transmitting mechanism for selectively braking rotation of said third member of said second planetary gearset;

a fourth torque transmitting mechanism for selectively braking rotation of said third member of said third planetary gearset;

a fifth torque transmitting mechanism for selectively braking rotation of said second member of said third planetary gearset, said fifth torque transmitting mechanism including an overrunning clutch that is operable in either of a released mode and a locked mode; and

an actuator for shifting said overrunning clutch between its released and locked modes.