An update. Today we finished machining the collar to go over the hub. We had an interference fit of 0.0035". I had decided on .003 to .004, so I felt quite confident.
We chilled the hub to about 0F in a deep freeze and boiled the collar. That should have given an assembly clearance of...
I thought that star lock washers worked by presenting a multitude of angled edges to the bottom of the head and its mating surface. The edges dig into the material so that it takes more torque to go against them and back out the fastener than was applied to tighten it, kind of like a ratchet...
Yes, I considered TIG welding them, but the HAZ will probably reach two of the six belt grooves. I'm afraid that in a -0 condition they would wear unacceptably. With the additional expense of heat treating the total would approach the cost of making a complete pulley.
Yep. You have accurately described the problem. And I understand what you're saying about the stress concentration as the base of the groove. I hope that the fine details like that are of such a minor nature that I don't have to worry about them.
My customer's main concern is that the...
OW! I'm getting brain-cramps and you throw that in! :-)
Good point! Its max speed could be 18,000 RPM or a bit more. I'll need to sheck the engine data and confirm the drive pulley size; a 3:1 ratio is just a reasonable guess. The section should be about .26" thick, not counting the larger...
Agreed that generate is a bad word here, but you understand my meaning correctly. "Withstand" is a much better choice.
And I meant foot pounds of torque. Dope slap self-administered. I've been translating metric and American values back and forth until my head spins. I deal with metric...
If I'm using it properly, the calculator linked above says that at .003" interference it will generate 295 Nm of torque. With the ratio between the engine and the driven sheave, that is almost 150% of what the engine puts out.
It also says that I need about 44 degrees K differential to get it...
Unfortunately I have no way to get the power requirement. Trying to calculate it from the RPM and displacement of the supercharger isn't practical because there are lots of unknowns.
I could build a belt tensioner with a strain gauge on it and calculate torque from that, but again, that's more...
Splines would involve more work than making a complete part. And there is very little wall thickness on the sleeve - 1/8" to 3/16" between the ID and the minor diameter of the sheave - I'm still working out the details. I fear that splines or keyways would weaken it too much.
I would think...
Thanks again, Mike! Another good idea with the screws.
I almost always use 6061 for machining because it's usually available in the configuration I need. My supplier in St. Louis carries lots of 6061, but only a few 2024 square bars and a modest inventory of sheet and plate. Round stock I...
Thanks, Mike!
The reason I don't want to make it as one piece is that it's a single complicated part that I have to turn on a manual-control lathe. There are two multi-groove serpentine belt sheaves and a very precise press fit onto a 5/8" driven shaft. That bore is deep in the part and would...
Thanks, Greg. That Wikipedia link was what I needed.
The FAQ suggests that I don't know enough to be here, so I'll just lurk until I get smarter. :)
Thanks again.
Jim
Hi! I'm new here, and a shade-tree mechanic.
My current project is to shrink fit a sleeve over a drive pulley hub. Both parts are 6061 T6. The hub has an I.D of 1.6" and an O.D. of 2.1". The sleeve will have an O.D. of 2.88" with 0.10" deep serpentine belt grooves in it.
In my copy of...