Shaft Spacer

[slickstyles5]

Hi,

I have a shaft with an outside dia. of 8 inches and inside dia. of 6 inches. I want to reduce the inside diameter to 4.5". Is there a way to determine the outside dia. or wall thickness required to respect the same properties of my shaft in terms of torsion?

Thanks

GAbriel

 

[nickelkid]

Polar Section Modulus, Zp = .196 ((D^4-d^4))/D)
D = OD
d = id
(From Machinery's Handbook)

Solve for Zp with 8"D and 6"d

Then solve for the equivalent D with a 4.5"d

 

[eromlignod]

If I'm understanding you correctly, you want to reduce the ID and determine what the equivalent OD would be to get the same torsional strength?

You would just calculate your present polar moment of intertia, then plug the new ID into the same formula and set it equal to what your present J is and solve for the OD algebraically.

I hope this isn't homework.

Don
Kansas City

 

[slickstyles5]

Nope it's for work.

Thanks a lot guys. I appreciate it!! Always so helpful!!