Official Baja SAE Forums Homepage
Forum Home Forum Home > General > Design Discussion
  New Posts New Posts RSS Feed - welding CV
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

welding CV

 Post Reply Post Reply
Author
Message
abhinav.chiku View Drop Down
Milling Master
Milling Master
Avatar

Joined: Aug/04/2012
Location: India
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote abhinav.chiku Quote  Post ReplyReply Direct Link To This Post Topic: welding CV
    Posted: Oct/14/2013 at 11:48pm
Ok.we are trying to make a custom CV to suit our design. We have male ( outer splines ) in gearbox output shaft. So we have manufactured a cylinder with female ( inner splines) the length of the cylinder is 10mm more than the length of splines. We took a Rzheppa joint and cut its outer spline shaft leaving 10mm length to mate in the aforementioned cylinder. Now we intend to weld the two parts like a Rod is weld perpendicular to a plate (weld around the outer circumference) the material of the splined cylinder and joint are same. I have also done calculations about the weld thickness and max shear stress of the material with a factor of safety of 2, taking into account the max working torque experienced by the joint by the gearbox. Also I intend to test the weld by rotation of the joint in opposite directions equal to th working torque.

So does someone have any experience or suggestions regarding the weld. Is it something not to be done after calculations and physical test. Anyone who has done something like this?

Edited by abhinav.chiku - Oct/14/2013 at 11:54pm
Abhinav Jain
Captain
Team Kshatriya International
VIT University
India
Back to Top
abhinav.chiku View Drop Down
Milling Master
Milling Master
Avatar

Joined: Aug/04/2012
Location: India
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote abhinav.chiku Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2013 at 12:22am
Abhinav Jain
Captain
Team Kshatriya International
VIT University
India
Back to Top
joey.m.gonzalez View Drop Down
Welding Master
Welding Master


Joined: May/09/2013
Location: San Diego, CA
Status: Offline
Points: 132
Post Options Post Options   Thanks (0) Thanks(0)   Quote joey.m.gonzalez Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2013 at 1:49am
If I'm understanding you correctly:

You machined a part to connect your gearbox to your inner cv joint?  There might be others on here that might disagree with me, but there will be a lot of funky moments on that piece from both the torque from the gear box and the loading from the tire (and that will change depending on the angle).  Will it work? Probably.  Would I do it? Nope.  I also think your factor of safety of 2 is quite low, in my opinion.

The amount of effort you spent machining that splined part, you could have made your own adapter that goes directly from the gearbox (replacing the current output) to the inner cv cup.  We did this with our gearbox and inner cv.  Held up to 4 hours of endurance in Oregon this past year, and many hours of screwing around since then.

Also, I would want to get that inner cv as close as I could to that gearbox help out with the cv angles (i.e. keep the cv's happy through the travel).

my .02

Joey
Back to Top
abhinav.chiku View Drop Down
Milling Master
Milling Master
Avatar

Joined: Aug/04/2012
Location: India
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote abhinav.chiku Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2013 at 2:18am
Joey.
Alright I got you. I can sure increase factor of safety of the weld to 3 or 4 something. And since now we have machined the cylinder with splines of the gearbox output. Would you suggest the whole concept. The only other option we have is to make a sleeve with two kinds of splines in it one for the inner CV the other for the gearbox output. Here no weld would be there . basically connecting the gearbox output and CV splines ( outer spline or male splines) by an intermediate sleeve with splines for both cv and gearbox.
The option replacing the gearbox output is not that that feasible for us.
So which one would you suggest.
Welding the cup to the CV like in the image or an intermediate sleeve with two different splines.
Abhinav Jain
Captain
Team Kshatriya International
VIT University
India
Back to Top
Soccerdan7 View Drop Down
Organizer
Organizer
Avatar

Joined: Sep/22/2010
Location: CA
Status: Offline
Points: 780
Post Options Post Options   Thanks (0) Thanks(0)   Quote Soccerdan7 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2013 at 10:49am
Be sure to take into account the bending and torque combined loading and shock loads such as landing a jump with too much throttle.

What are the 2 alloys you are trying to weld? I believe most stock CVs are substantially hardened. If it is only a case harden, you can probably weld to it after you turn / grind off the case. 

I would also strongly recommend heat treating the welds to reduce the effect of the HAZ. What knowckdown in yield strength have you been using to account for this?

Also, if you have inboard brakes or a reverse gear, the load cycling could potentially cause a fatigue issue. A car with outboard brakes and no reverse gear sees pretty much all torque loads in 1 direction only.
Danny

Cornell

(fall'07 - spring'12)
Former Captain / MEng / that guy with all the carbon
10 races, 7 top ten's, 2 overall wins
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 1.141 seconds.