Gm Global Technolgoy Operations, Inc.

Kumar V Hebbale

Dongxu Li

Chi-Kuan Kao

Chunhao J Lee

Farzad Samie

A continuously variable transmission, a transmission control system, and a method is provided. The control system is configured to determine whether a predetermined condition is met for applying a clutch critical pressure to an applied clutch. The clutch critical pressure is less than line pressure and is a pressure at which the clutch may slip upon experiencing a predetermined torque disturbance level. The control system is configured to command the clutch critical pressure to be applied to the clutch if the predetermined condition is met. The control system is further configured to determine whether the clutch is slipping beyond a predetermined threshold, and if the clutch is slipping beyond the predetermined threshold, command a clutch slip control scheme to be applied to the clutch that is configured to bring a clutch slip of the clutch under the predetermined threshold.

Clutch control in a continuously variable transmission

A multi-speed clutch-damper assembly for selectively connecting an output of a power-source to an input of a transmission includes a planetary gear-set. The planetary gear-set is encased in a housing and configured to provide two selectable speed ratios and a damper between the power-source output and the transmission input. The planetary gear-set includes first, second, and third gear members. The second gear member is configured to be connected to the transmission input and the third gear member is configured to be selectively fixed to the housing. The planetary gear-set also includes an elastic element operatively connected to the second gear member and configured to generate torsional vibration damping between the output of the power-source and the input of the transmission. The clutch-damper assembly also includes a first clutch configured to selectively connect the power-source output to the first gear member for transmitting torque of the power-source to the transmission.

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Troy, MI, United States of America

Kumar V Hebbale