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How the Roller Gearing Mechanism Works

In our patented roller gearing and transmission mechanism power is transmitted from the driving body to the driven body via a series of rollers that carry out pure rolling motion. This means that unlike in conventional gears there is no sliding friction among the moving parts but rolling friction only. Rolling friction is by about 100 to 500 times smaller than sliding friction and thus frictional energy losses in the roller gearing mechanism are by about 100 to 500 times smaller than in conventional gears - in fact they are practically negligible. 

We apply rollers to intermediate between the driving and the driven bodies and use fundamentally new and specially designed shapes for the surfaces of the driving and driven bodies in order to ensure that they facilitate pure rolling motion for the rollers. 


The rollers are in simultaneous contact with the surfaces of both the driving and the driven bodies and are embraced by grooves developed onto the surfaces of the two bodies. 

When the driving body moves it exerts force on the rollers that pass the force on to the driven body through their contact point. As a result the movement of the driving body is translated into a movement of the driven body while, in the meantime, the rollers roll along the grooves on the surfaces of both bodies.

When a roller reaches the end of its groove it simply falls off of it and the coupling of the two bodies as far as this particular roller is concerned is finished. The ball is then guided back to the surface of the two bodies where the grooves begin and enters another groove again and create a new coupling between the two bodies again. The continuous line of several rollers makes it sure that there is continuous and rigid coupling between the two bodies at all times. 

The design of roller gears including the rollers and the specially shaped driving and driven bodies is fundamentally different than that of conventional gears and as a result besides negligible frictional energy losses further additional advantages arise. For example, back-lash in the roller gearing mechanism can be eliminated easily by simply preloading the driving and driven bodies and the rollers between them by some force pushing them against each other. This can be done without significant increase in friction among them or any other problem such as jamming. This is typically very difficult and expensive to do in conventional gears due to obvious structural reasons. Eliminating back-lash and thus reducing noise, heat, thermal expansion, wear and tear, increasing precision, lifetime and reliability, just to mention a few of the advantages, is very important in practically all applications. This is another major improvement compared to conventional gears in its own right.  

Another beneficial 'side-effect' of the new mechanism and yet another very important improvement to conventional gears is the potential for a high engagement factor. It is quite natural in this design to employ a series of rollers that are in simultaneous contact with the driving body and the driven body. The arising engagement factor can be as high as ten or twenty or even higher. This gives rise to a number of advantages including smooth running, precise movements, low noise, small size, cheap raw material and great reliability.


Two further features illustrate how different this mechanism is from conventional gears. For example, the (relative) direction of rotation of the wheels is an input parameter when designing roller gears and we get a soluton for groove structures for either direction. That is one set of grooves (pair of wheels) for the opposite direction and another for the same direction. Note, there is no need for a third wheel and shaft to create a gear with the same direction of rotation - unlike in the case of concventional gears where it is abolutely necessary. This creates a major opprtunity to reduce size, weight, complexity and production costs, while increasing efficiency further.

Quite conter-intuitive from the view point of conventional gears, one can adjust (within reasonable limits) the gearing ratio without changing significantly the diameter (ratio) of the wheels. This is possible because the ratio is a function of the pattern of the groove structure and not directly related to the diameter of the wheels. Vice versa, one can keep the gearing ratio while adjusting the geometric size of the wheels. This makes it possible to provide a much richer set of solutions for a given problem than that of conventional gears which helps to optimise the gear system better.

In summary, this mechanism may require a whole new mindset and intuition than the one we have from conventional gears. The mechanism could be said resembles more in its operational features to a ball screw or ball bearings than to conventional gears with connecting teeth involved. Yet it is infinitely richer in its geometrical and applicational varieties than conventional ball screws with several additional degrees of freedom added to the system.