Borgwarner Inc.

Darren L Firth

Melissa Mei Koenig

Mark Buchanan

Richard Terrence Tamba

Anthony J Grzesiak

Thomas G Brand

Chris Denault

A brake band shifting mechanism for an automatic transmission. The brake band shifting mechanism includes a brake band encircling a brake drum of the transmission. A first end of the brake band is mounted to a secured portion of the transmission by a first linkage and a second end of the brake band is mounted to a two-stage servo by a second linkage. The servo provides selective apply and release pressure to the second linkage to control the compression or expansion of the brake band. In operation, the brake band is quickly compressed to the brake drum during the first stage of the servo, and then fine adjustments are made to control the speed of the brake drum during the second stage of the servo, where inputs from position and speed sensors in the transmission are used to control the adjustment of the brake band.

Brake bands for an automatic transmission and method for controlling a gear shift in automatic transmission and feedback loop control system

A method of controlling the engagement force of the synchronizers of a dual clutch transmission having a plurality of synchronizers to selectively engage and disengage various gear sets, and a plurality of shift actuators adapted to move the synchronizers. The method includes the steps of initiating a control routine to pressurize a shift actuator to move a synchronizer to a predetermined engagement position and determining the necessary level of force required to move the desired shift actuator to the predetermined engagement position such that the engagement movement is effected without excessive force. The method also includes the steps of determining the hydraulic pressure that corresponds to the determined level of force and varying the amount of available hydraulic line pressure delivered to the shift actuator such that the delivered pressure is the amount that corresponds to the determined level of force.

Method for controlling the engagement force of the synchronizers of a dual clutch transmission

A method of controlling the positioning of the synchronizers of a dual clutch transmission having a plurality of synchronizers to selectively engage and disengage various gears sets, and a plurality of shift actuators adapted to move the synchronizers. The method includes the steps of initiating a control routine to move a synchronizer to a full engagement position with a gear set and monitoring the positions of all engaged synchronizers. The method also includes reinitiating the control routine to move a synchronizer back into the full engagement position when any engaged synchronizer slips out to a minimum engagement position. Further, the method includes initiating a control routine to move a synchronizer to a neutral position and monitoring the position of all disengaged synchronizers. Also, reinitiating the control routine to move a synchronizer back to the neutral position when any disengaged synchronizer drifts beyond a pre-determined neutral hysteresis position.

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Parramatta, Australia

Darren L Firth