Gm Global Technolgoy Operations, Inc.

Christopher Brian Ross

Michael Colby Sefcik

A powertrain has a multi speed power transmission including a planetary gear arrangement with three simple planetary gear sets and six selectively engageable, fluid operated, friction torque transmitting mechanisms. A one-way torque transmitting mechanism is disposed in parallel drive relation with one of the friction torque transmitting mechanisms. The selective engagement of the friction torque transmitting mechanisms will establish seven forward drive ratios, a neutral condition and a reverse drive ratio. All of the forward ratio interchanges are single transition shifts and all of the single ratio skip shifts are single transition shifts. The seven forward drive ratios include four underdrive ratios, a direct drive ratio, and two overdrive ratios. The planetary gear arrangement can be controlled to establish six forward drive ratios with either one overdrive ratio and four underdrive ratios or two overdrive ratios and three underdrive ratios. A five speed arrangement having four forward underdrive ratios, a forward direct ratio a neutral condition and a reverse drive ratio while permitting the elimination of one of the friction torque transmitting mechanisms.

Multi speed power transmission

A fluid operated selectively engageable torque transmitter has a fluid operated piston that is pressurized to initiate engagement of a plurality of friction plates. The plates are alternately splined to an input member and an output member. One of the input or output members has a hub member threadably engaged therewith. The hub member has one set of plates and an apply plate splined thereto. Also connected with the threaded hub is a reaction plate. When the piston is lightly pressurized, the hub will traverse the input or output member on which it is threaded until the apply plate abuts a reaction surface on the member at which point the torque transmitter will be fully engaged. Upon a torque reversal, the threaded hub will traverse in the opposite direction to disengage the torque transmitter, thereby providing a direction sensitive mechanism. When the piston is fully pressurized, the torque transmitter will respond in a normal manner to transmit torque in both directions.

Selectively engageable torque transmitting mechanism with a one-way screw apply

A torque transmitter has a plurality of friction plates alternately splined at the inner and outer peripheries. The plates are urged into frictional engagement by a piston and a lever spring to accommodate torque transmission between the splined components drivingly connected with the splined peripheries. The friction plates are disposed in radial alignment with the piston and the lever spring reacts against one of the friction plates. A fulcrum for the lever spring is disposed on one of the splined components.

Growing community of inventors

Chelsea, MI, United States of America

Christopher Brian Ross