Precessional drive gearbox

Imperial Innovations have the rights to an innovative drive concept using gyroscopic precession to translate high velocity, low torque motion into low velocity, high torque motion to provide the motive force for vehicles as an adaptive gearbox.

In summary the device uses twin counter rotating flywheels mounted in parallel either side of a central shaft. Pivoting the flywheels evenly about their diameters induces gyroscopic precession of the whole shaft.

A two phase project to examine the feasibility of this concept was funded by the Carbon Trust. The first phase was a mathematical investigation of the concept using derivations of the standard gyroscopic equations to verify that theory supported the principles.

The second phase was to design and build a physical model that was used to experimentally test the principle of operation and serve as a technology demonstrator. A physical demonstrator had been attempted before, but the results were obscured by additional challenges associated with the input drive mechanics. 42 Technology suggested that we abstract the drive input problem by using twin electric motors and concentrate on the key area of technical risk and understanding.

Testing of the completed demonstrator showed that in principle the torque conversion worked and the flywheels do exchange energy with the rest of the system. The results also indicated various key operating parameters.

Consideration of the potential applications of the technology suggested that it is most likely to be exploited in heavy, high mileage vehicles with complex acceleration profiles (e.g. urban busses). Estimates indicate that using the system as a combined energy store and torque converter to create a hybrid vehicle could lead to significant reductions in CO2 emissions.