Splines that don't slide - but should.
Splines that don't slide - but should.
(OP)
I am designing an assembly station in which a splined hub and shaft are assembled. "99 times out of 100"", the shaft will just slide into the hole under its own weight. But some times it will need a bit of help. Call me cynical but I was not surprised to learn that nobody could quantify a maximum insertion load before the assembly should be rejected. But I have to design the machine anyway. It would be nice if I could justify using a medium sized pneumatic cylinder, instead of a hydraulic ram. Your comments and help will be much apreciated.





RE: Splines that don't slide - but should.
I would concentrate on getting the 99 out of 100 and providing a quick and smooth solution for rejecting or recycling the 1 in 100. Keep the line going!
The ultimate goal is to produce the maximum number of assemblies in a given time period at the least cost. If during the shift you have 20 spline assemblies that need manual rework or need to be checked and re-loaded into parts bins would it be acceptable?
The customer/boss is probably asking for 100% but knows it will not happen.
Barry1961
RE: Splines that don't slide - but should.
If on the other hand the splines are for positioning or for strength then you may wnat a large press fit type of force.
Which do you have?
Regards
Dave
RE: Splines that don't slide - but should.
RE: Splines that don't slide - but should.
Thanks again,
Colin.
RE: Splines that don't slide - but should.
RE: Splines that don't slide - but should.
These are automotive components (Land Rover Discovery Rear Hub), so I would expect them to have been inspected every way you could imagine and a few more besides! I posted this to see if anybody out there had heard of "transition fit" splines. I am pretty sure that they do not exist.
RE: Splines that don't slide - but should.
I suspect you are suffering from contamination, burrs or nicks, rather than a statistical tolerance stackup.
Mike Halloran
Pembroke Pines, FL, USA
RE: Splines that don't slide - but should.
the splines can have any fit - even the press (interference) fit. I am talking about the "side fit" and also the "OD fit".
Check the widely used standard DIN5480, Part 1 and Part 14.
In that standard you can also find the methods for calculating the gages for checking splines with any of those fits.
You should have the detailed info about both splines - the customer's and obviously yours. Do some math and check the fit. It is not simple, but doable. And proper gage for both internal and external splines is a must; how can you proove that the customer's splines are really correct?
RE: Splines that don't slide - but should.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Splines that don't slide - but should.
thanks but I do not work for LandRover, I am a subcontractor to a subcontractor of a partner that supplies Land Rover. I am not sure you can talk to me.
GearGuru and MikeHalloran thank your info.
"You should have the detailed info about both splines - the customer's and obviously yours.?"
You would have thought so wouldn't you....
If any body from an automotive company is listening... The reality is:- The factories where components are assembled are not where the components were designed. The companies that manufacture mass produced components have process sheets and op sheets and dedicated machine tools, and drawings for each process, but not drawings of the finished component, because they do not need them.
Companies like mine would love to have drawings of finished components, which is obvious to every one , and they always say that they will give them to us. But normally they do not exist!
Sorry forgive my little bit of a rant. Thank you again for all your help.
Colin
RE: Splines that don't slide - but should.