TRA J contour
TRA J contour
(OP)
In the "round/round" J contour in automotive wheels, I have noticed an indent under the inboard round hump on the barrel. It matches the profile of the round hump perfectly. Some wheels have it, some do not. I hope hoping someone could let me know the reason for the hump indent in this location.
Clarification: There is an indent in the revolve of the barrel underneath the inboard round hump. Not sure of a better way to describe this.
Clarification: There is an indent in the revolve of the barrel underneath the inboard round hump. Not sure of a better way to describe this.





RE: TRA J contour
maybe with a picture?
RE: TRA J contour
RE: TRA J contour
RE: TRA J contour
Link to image: INBOARD FLANGE.png
If that is a correct assumption on my part......
The main purpose of the indentation, from my experience, is to reduce weight. It can also provide an area to transition from a thicker wall in the inboard bead seat area (between the flange and the safety hump) to a thinner wall as you travel down the profile towards the outboard flange (towards the the drop well).
The wheels you see that lack this design feature - the machinists probably feel it's faster to machine the wheel without the ID indentation or they've experienced rim failures during pot hole testing and want the added material for more hoop strength to help avoid warranty issues as much as possible.
I've also ran into designs with a hump in that ID area for stick-on wheel weight location purposes - keeps the weights away from the brake as well as far enough from the centerline that they're more effective in balancing the rim. The design of the ID of the rim isn't as crucial as the OD in most instances - just offset from the OD, have enough material in the wall thickness and don't hit the brake caliper and all should be fine given proper metal processing.
Tim Flater
NX Designer
NX 9.0.3.4 Win7 Enterprise x64 SP1
Intel Core i7 2.5GHz 16GB RAM
4GB NVIDIA Quadro K3100M
RE: TRA J contour
RE: TRA J contour
Tim Flater
NX Designer
NX 9.0.3.4 Win7 Enterprise x64 SP1
Intel Core i7 2.5GHz 16GB RAM
4GB NVIDIA Quadro K3100M
RE: TRA J contour