Inception Drive: A Compact, Infinitely Variable Transmission for Robotics • Hacker News Board

Re: Inception Drive: A Compact, Infinitely Variable Transmission for Robotics

#51

Post by Animats » Thu, Sep 21, 2017, 5:02 PM UTC

dom0 wrote: post #42

Animats wrote: post #33

This is cute, but the use case in robotics is questionable. A variable ratio transmission for a robot seems to solve a problem nobody has. Electric motor control today is able to do that job over a wide torque and speed range. From drones to electric cars to Diesel-electric locomotives, nobody uses variable-speed gearboxes much any more. There are many robot gearboxes, but I've never heard of one with a shifter. Mach…

I think one of the very few remaining applications of variable-speed gearboxes are wind generators with no converter. But this in itself is rare, because it may be more reliable (?), but also less efficient than the power electronics... (afaik off-shore wind generators are going completely gearless).

Wind turbine gearboxes are all fixed ratio, as far as I can tell. The blade pitch is adjusted to maintain a constant speed in synchronous machines. Ones with AC-DC-AC converters don't need to do that. There's also something called a "doubly fed machine", which is a 3-phase generator where the field windings are actively driven to rotate the magnetic field to compensate for minor speed variations of the rotor.

Wind turbine gearboxes take a lot of pounding as the wind shifts. Wear is a big problem and not fully understood. The trend is toward gearless systems. Transmission repair atop a wind turbine is not fun. Power semiconductors are good enough that it's easier to deal with this electrically.

Re: Inception Drive: A Compact, Infinitely Variable Transmission for Robotics

#52

Post by dom0 » Thu, Sep 21, 2017, 7:12 PM UTC

Animats wrote: post #51

dom0 wrote: post #42

Earlier quoted context omitted.

I think one of the very few remaining applications of variable-speed gearboxes are wind generators with no converter. But this in itself is rare, because it may be more reliable (?), but also less efficient than the power electronics... (afaik off-shore wind generators are going completely gearless).

Wind turbine gearboxes are all fixed ratio, as far as I can tell. The blade pitch is adjusted to maintain a constant speed in synchronous machines. Ones with AC-DC-AC converters don't need to do that. There's also something called a "doubly fed machine", which is a 3-phase generator where the field windings are actively driven to rotate the magnetic field to compensate for minor speed variations of the rotor. Wind tu…

IIRC Voith developed these... I'm in no way an expert about these, but I'd guess that going gearless and using a slow-running generator would have the advantage that you get a much longer and fatter shaft to put bearings on.

Re: Inception Drive: A Compact, Infinitely Variable Transmission for Robotics

#53

Post by wpennington » Fri, Sep 22, 2017, 1:06 AM UTC

captaindiego wrote: post #26

bittercynic wrote: post #5

Maybe the greatest feature is that it can have a very high ratio while avoiding Harmonic Drive related IP.

Does anyone know if this Inception Drive will be patented heavily as well? Or if it will be fairly easy to build products around this sort of design?

Given the work is being completed at SRI, I would assume the tech would be positioned in a patent or portfolio of some sort. However, this is purely speculation. Nevertheless, this suspicion is further supported by the fact the inventor has a history of patenting for commercialization. That's largely the SOP at SRI and central to their business model.

However, worth noting that just because a patent is filed doesn't mean it (or all of it) will be allowed. So, wrt your second inquiry -- assuming the tech was filed on -- whether or not it can be designed around will largely depend on 1) what was claimed in the patent (e.g., how broad and thorough the claims are) and 2) what is eventually allowed by the examiner. The latter is largely a product of the prior art in the space.