odd taper

[rmetzger]

I have a request for a taper drive that is unidentified - wondering if anyone knows if its a standard or not. The angle off the centerline of the taper is 3 degrees 35 minutes and it has a .500 drive tang off the end (end dia approx 1"). Any ideas?

 

[CorBlimeyLimey]

http://www.gizmology.net/tapers.htm

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[BillPSU]

If your numbers are correct I would say you have a 1.500 inch per foot taper measured on the diameter. I don't know if that is a standard or not.

 

[rmetzger]

Thats what I calculated it to as well - we have an older print that almost matches the angle (has a keyway that this design doesn't share) but can't find a reference from any standard it may have come from. It may just be an odd-ball from the past that has never been changed.

 

[griffengm]

Rmetzger,
I'm going to stick my neck out here and say that this is a 7° included angle taper. From a somewhat limited exposure to these, this is sort of a dividing point between self-locking taper and non-locking.
When I worked with these, we used 7° because the tool would self-lock but took a minimum amount of force to loosen it when changing tools. In other words, a more shallow taper, say 4-5° included would lock so tightly that you might destroy a drift removing them. 10-12° would almost fall out and so needed some sort of retainer.

Griffy

 

[BillPSU]

Is this part a sheave or some other rotating part. Its been many years but on combines there were sheave with tapered bores which then had a split sleeve pushed into the taper to lock on a round shaft. I don't remember what the taper was but I made thousands while working for Allis Chalmers.

 

[rmetzger]

Its an input drive to an engine (transmitting starting torque at around 3000rpm). I haven't gotten all the details of the system yet but I'll post them when I do.

 

[griffengm]

rmetzger,
This wonldn't happen to be a rotax or cuyuna engine would it?

Griffy

 

[rmetzger]

I doubt it, most of the engines that we are designing to are larger (50 liters+) than I think either of those two companies make.