Orbital Gearbox
Very small 2-speed gearbox, that is rotated by 180 degrees to change gears.
A very simple concept of a gearbox, where the actual gearbox is built into wedge wheels and rotated by 180 degrees in order to change gears. The design is extremely compact, and – if you can rotate the gearbox accurately enough – works very smooth, as there is no problem with engaging / disengaging gears. The disadvantages are: somewhat loose construction, that makes the gearbox unable to handle large torque, and slightly unwieldy layout, with rotation axle between the input & output axles. It is, however, perfectly possible to control rotation axle from one side of the gearbox, and connect input & output to the other side. The fact, anyway, is that as of the end of 2008, I still haven’t used this design in a single project.
The problem of setting the gearbox into a proper position can be easily solved by using some kind of rotation limiters, and then rotating gearbox forwards and backwards. That would, however, require the use of a clutch, and the clutch may cause the gearbox to yield under torque. Probable solutions include using a worm gear or pneumatics. As mentioned above, personally I have not yet had any low-torque application that would require the use of this gearbox.
