Quote:
Originally Posted by JWA
^^^ Without offense you're over-thinking all this.
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Well ain't that the truth
This is true of basically anything I do... and then once I finally do whatever is I've been over-thinking, I forget all about it and find the next little thing to obsess over.
Quote:
Originally Posted by JWA
In the hub-centric design vehicle weight is borne more by the wheel-to-axle interface, wheel studs and lug nuts function reduced to clamping the wheel to the hub or axle.
We've been using the hub-centric wheels and axles for quite a few years so far, no major design failures in actual use that I'm aware.
For a component as important as a wheel and how it fits onto the chassis I'm not so bold or brave to begin experimenting with ideas that have not found their way into more common or frequent use.
Good luck with your project---will be interested in its outcome.
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To be clear, I am in no way saying that the hub-centric wheels are prone to failure. But also, the lug-centric wheel design is not necessarily an "uncommon" design, as far as I know.
So with that being said, I appreciate your input and totally understand if you don't want to continue this discussion! But (mostly) for my benefit, and in the off chance that it may help others on this forum, I'll go through the trouble of drawing up some highly sophisticated diagrams to better convey my thoughts. I would love if JWA and/or others would want to chime in on this topic, but I'm happy to keep blabbing on here by myself as well
I'll start this off by saying this is all predicated on the assumption that the ID of the wheel must be slightly larger than the OD of the lip on the hub ("hub-centric feature").
[1] In a perfect world, when the wheel (yellow) is bolted to the hub (blue), the ID of the wheel would be perfectly concentric with the hub, as shown below:
[2] However, as mentioned above, the ID of the wheel is slightly larger than the OD of the hub lip. So, when the vehicle is up on the lift and the wheel is bolted on, the wheel actually settles onto the hub slightly off-center, since gravity pulls the wheel downward:
When the lug nuts are tightened, they clamp the wheel against the hub and prevent their relative motion. This is a
bolted joint where the bolts (or in this case, studs and lug nuts) are loaded in shear. From the wiki link:
"For the shear joint, a proper clamping force on the joint components prevents relative motion of those components and the fretting wear of those that could result in the development of fatigue cracks."
[3] Now we add a marker line on the top of the wheel so we can visualize its rotation:
At this point, let's say the vehicle is lowered onto the ground and the weight of the vehicle is resting on the wheels. In order for the hub lip (blue) to be supporting the weight of the vehicle, it would have to be touching the bottom of the wheel ID. But since the wheel was clamped against the hub by the lug nuts, it can't move relative to the hub.
[4] Now let's say the vehicle rolls forward enough to rotate the wheel 180 degrees. Now the hub lip (blue) is touching the bottom of the wheel ID and I suppose could be supporting the weight of the vehicle. But this condition does not hold true throughout the full rotation of the wheel.
Linear Mode
