Variable speed transmission and system using same

A system comprising:

• a constant-speed driver;
• a rotating load configured to be driven into rotation by the constant-speed driver;
• a controller, for controllably changing a rotation speed of the load;
• a variable speed transmission, arranged between the constant-speed driver and the load, the variable speed transmission comprising a speed summing gear arrangement with a first input shaft, an output shaft, and a second input shaft;
• and
• a continuous variable transmission device mechanically coupled to the constant-speed driver and configured co-axially with the first input shaft, the second input shaft, and the output shaft of the speed summing gear arrangement so as to modify the speed of the second input shaft of the speed summing gear arrangement, the continuous variable transmission device comprising,
• a sleeve formed integrally with the second input shaft of the speed summing gear arrangement, the sleeve having a bore co-axial with the first input shaft, and
• a magnetic coupling having magnets mounted to an inner surface of the bore on the sleeve and an electrically-conductive member at least partially disposed in the bore and attached to the first input shaft so that the electrically-conductive member co-rotates with the first input shaft,
• wherein the output shaft is drivingly coupled to the rotating load and the first input shaft is drivingly coupled to the constant-speed driver, and
• wherein the speed of the output shaft is a function of the speeds of the first input shaft and of the second input shaft and the continuous variable transmission device is functionally coupled to the controller, such that the rotation speed of the rotating load drivingly coupled to the output shaft can be modulated, while the rotation speed of the constant-speed driver remains constant.