Torque monitoring system and method of monitoring engine torque

A torque monitoring system for a vehicle drivetrain including an engine with an engine output shaft and a transmission, comprising:

• a first rotatable member rotatably driven by said engine;
• a second rotatable member;
• a structural member at least partially forming a closed fluid chamber between said first and second rotatable members;
• wherein rotation of said first rotatable member pressurizes said chamber to rotatably drive said second rotatable member;
• a pressure sensor mounted in contact with said fluid chamber and operative to sense a pressure level within said chamber and transmit a sensor signal correlated with said sensed pressure;
• wherein said first rotatable member is a flex plate connected for common rotation with the engine output shaft and is operatively connected with the transmission, said sensed pressure level being mathematically correlated with torque of the engine;
• and
• a controller in signal communication with said pressure sensor and operable for receiving said sensor signal and varying an operating condition of the drivetrain based on said sensor signal.

A method of monitoring engine torque comprising:

• hydraulically connecting first and second coaxial rotatable members by providing a hydraulic chamber connected therebetween;
• wherein said first rotatable member is driven by an engine and said second rotatable member is operatively connected with a transmission;
• rotating said first rotatable member via engine torque to thereby rotate said second rotatable member via pressure in said hydraulic chamber resulting from rotation of said first rotatable member;
• sensing a level of pressure within said chamber;
• relaying a signal corresponding with said sensed level of pressure to a controller;
• and
• adjusting an operating condition of one of said engine and said transmission based on said relayed signal.