Power train

A power train comprising an infinitely variable transmission including a first adjustable rotary sheave arranged to receive torque from a prime mover, a second adjustable rotary sheave arranged to receive torque from said first sheave by way of at least one endless flexible element which is trained over said sheaves, and at least one adjusting unit for each of said sheaves, said units being regulatable to vary the magnitude of torque being transmitted between said at least one flexible element and the respective sheaves;

• a hydromechanical torque sensor conected between at least one of said sheaves and said prime mover and operative to transmit at least a portion of torque being transmitted by said prime mover, said sensor having a plenum chamber, means for connecting said chamber with a source of pressurized hydraulic fluid, an outlet for evacuation of fluid from said chamber and at least two valving elements disposed at said outlet and movable relative to each other to establish at said outlet at least one fluid pressure which is a function of the magnitude of transmitted torque and determines the regulation of torque by said units;
• and a jet pump having a first inlet connected with said outlet and a second inlet connected with a source of hydraulic fluid.