×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Metal Thermal Expansion Question (CTE mismatch)

Metal Thermal Expansion Question (CTE mismatch)

Metal Thermal Expansion Question (CTE mismatch)

(OP)
Hi guys,

I have a quick question about the thermal expansion and CTE mismatch of metals. Basically I have a bronze bearing riding over a shaft and inside a journal. The bronze bearing is press fit into the steel journal (ID of journal = 1.124", OD of Bronze bearing = 1.125")and the steel male drive shaft rides inside this assemble. The steel male drive shaft has an OD of 1.000", and the bronze bearing has an ID of 1.003". This gives 0.003" clearance. Our operating temperature is 500 degrees F. At this temperature, is it possibly for this whole assembly to lock up?? I know bronze wants to expand more than the steel, but I'm not sure how this behaves when it is being constrained on all sides by the steel journal. Any input would be greatly appreciated.

Thanks,
M

RE: Metal Thermal Expansion Question (CTE mismatch)

Yours is not an unusual application. I believe that the main way to avoid problems here is to keep the bronze thickness low. The steel outside the journal may also need to be heated, or at least insulated from the rest of the structure to allow it to heat and expand. In some cases the bushing can be cut into three segments or shoes with one being spring-loaded.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources