Axle retainer bars: 1.5 x 0.5", two holes

VEX V5 General Discussion New Product Ideas
1

Using a patent application questionare approach, for this very simple idea.

  • Describe your new product idea:
    A 1.5 x 0.5 inch flat metal bar with square holes 1 inch apart.
    ie: a 3 hole piece of bar with the middle hole filled in.
    An alternate version has two adjacent holes and the missing hole at end,
    for when end hole of bearing is used for axle.
    Combined version is 4 units long: hole, hole, blank, hole
    Too bad I don’t know CAD enough to provide a drawing.

Alternate materials version:
metal: sharpen point of axle to minimize friction
Plastic: slippery plastic holds axle with minimal friction on spinning end of axle

The retainer can be sandwiched between the bearing and its supporting plate: bearing,retainer,structure.

Or the retainer can be added as an after-thought to the outside of the structure: bearing, structure, retainer.

The retainer can be attached in common with the bearing,
or attached at 90 degree angle with its own fastners that can be loosened or removed without touching the bearing fastners.

  • What problem does this solve?
    axles slide out of motors and gear boxes and wheels

  • What previous solutions exist?
    axle locking collar,
    anti-slip surface modifications to axle to increase its friction
    (ie grip with toothed pliers to make ridges on axle)

  • What are limitations of previous solutions?
    Friction solutions make axle harder to install, and are less reliable.
    Collar solutions take up space on axle, discourages use of motor clutch,
    Collar set-screws are less reliable than my proposed solution.
    Collar provides larger moment arm of friction against structure.
    Example1 axle stack: motor, clutch, structure, bearing, wheel, collar, bearing, structure: use of collar forces structures to be farther apart.
    Example2 axle stack: motor, collar (no clutch), structure, bearing, wheel, bearing, structure: with structures at minimum distance, use of collar forces clutch to be eliminated.
    Example 3 gearbox axle: bearing, structure, collar, gear, gear, structure, bearing : collar increases width of structure.

  • What differentiates your solution?
    Install this axle retainer bar stacked with the bearing block,
    the lack of center hole in the retainer keeps the axle from sliding out.

Example 1 axle stack: motor, clutch, structure, bearing, wheel, bearing, retainer, structure: Since retainer is thinner than collar, the structures on each side of the wheel are less far apart. This may remove the need for washers in the original stack as well.

Example 2: motor, clutch, structure, bearing, wheel, bearing, structure, retainer:

Example 3 gearbox axle: retainer, bearing, structure, gear, gear, structure, bearing, retainer.

2

If i understand this correctly then you want it to be an alternative to shaft collars. The issue i see is that the axles are not always flush to the edge of the chassis. Therefore you would need to install washers or something to make it work. If you already don’t have room to get the shaft collars in you are going to have to work really hard to get a bolt in and then put washers on it and tighten everything up. It seems like an alright idea but only works in rare situations.

I would get a book and learn CAD. I have used solid works or pro desktop to CAD up my last few robots and although it does take some time (less as you get better) your end result is a picture of what you want and you could just hand it to someone with a little bit of experience and say “Go” and they could do it. It also helps plan out all of the “nuts and bolts” of building. I find that i often times have ideas in my head but when i CAD them up i realize that i need to change something around to make everything fit and it is nice to find these mistakes BEFORE you already have a lot of the thing built.

In designing i see three kinds of people the ones who sit in front of a computer and design it in a CAD program and the ones who grad some pieces and kind of lay them out on the table and move them around. The ones that i find really valuable are the ones who do both. Often times CAD guys forget about real world aspects such as gear slop or that pieces may bend under load. And sometimes the guys laying out pieces don’t figure out how much room they need for a gear box until that have already built the darn thing. The guys who do both tend to be really precise and design with real life slop in mind.

I was recently made the manager of the design group for my FRC team (as a sophomore) and when picking my group members i looked for all three kinds of designers and i must say i am looking forward to working with all of them and think we will produce some awesome stuff together.

sorry, that went a little bit off topic but it is all relevant in a way.

~DK