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Unread 16-09-2003, 13:56
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Madison Madison is offline
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Quote:
Originally posted by Jnadke
bzzt... wrong answer.
In any case, my point is that the differential design, whoever it is developed by, is different and is the subject of its own threads and discussion. Why it does or does not work isn't relevant to this thread. Thanks.

Quote:
I've considered many similar designs to your clutch. Also, I would like to note that a simple search at McMaster Carr would yeld clutch bearings (aka ratchet bearings, one-way bearings). I would know because I've looked at them before for this purpose.
I've looked at what's available through McMaster-Carr in the past and either ruled it out or flat out forgot about them when I began this design last week. I'll look again and see if those products are applicable to this concept. If they are, that's a great thing because it greatly reduces the machining complexity required and brings the design within reach of most teams.

Quote:
The bad side is: propulsion in reverse. You could only do this using the high-speed, low torque motor. Everybody knows that robots often get pinned. A high-torque reverse is a nice thing to have...
Agreed. But, remember, this is just a gearbox. There's nothing stopping anyone from attaching it to something fancy like a swerve drive or something. Additionally, if the products available through McMaster-Carr are viable (I'm concerned about the torque loads they're designed for), creating a similar system that works in forward and reverse becomes a bit less prohibitive. It's still possible in either case as I already mentioned, however. This is just the starting point and there are many improvements that could be made upon this concept.

Paul -- I am very interested in what you come up with and your suggestions.

I'll admit that my understanding of motors and gearboxes and things is a bit rudimentary. There could be large swaths of important information that I've failed to account for.

Also, forgive me for my bad comparison of your CCT to the Prius' arrangement. Where planetary gearsets are concerned, the moment someone talks about locking the ring gear in place, my mind shuts down. I've never been able to sufficiently imagine how that's accomplished. I'll go read through your whitepaper again.

Edit:
It seems like part #2489K14 from McMaster-Carr (www.mcmaster.com) would do the trick. The only mitigating factor might be how high above 40A the current can spike before the breaker trips -- if it's too high, above about 70A -- it'll exceed the specifications of the clutch bearing. This all assumes my drill gearing of 1:2 as well. Anything lower than that would also exceed the specifications of the clutch bearing.

Additionally, it seems like you can reverse the orientation of the clutch bearing on one side -- eliminating the usual need of having to run your drill motors in opposite directions and compensate for the difference in programming.

I'll work on a second iteration that includes this clutch bearing. The first problem I see is finding a way of mating the clutch bearing to a gear -- either by welding it (they seem to be plastic, partly) or by press fit. I really have no idea at all if a press fit is capable of transmitting 25-35Nm of torque.
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Last edited by Madison : 16-09-2003 at 14:39.