Assembly Task Suggestions

Just a thought (if you have not thought of this before), can the stem be cold-soaked in dry ice to shrink the OD of the stem prior to assembly? Can the SS bushing be heated to expand the ID of the bushing? That might make assembly a bit easier than just pressing the parts together.

I am not aware if portable equipment exists. But I am not an expert either!

Thanks Reid.

The heated sleeve was an option which was considered too. The client has issues with this process.

Moreover, as a first choice, the current practice is to jam the sleeve & is a proven method for the client.

Regards,

Simha

Ried is right! Try shrink fit method. Keep the ID of the sleeve smaller than the shaft( How much smaller?) any machinery handbook would specify the "shrink and Fit" tolerances grades. Heat sufficient oil and place the sleeve in it for an hour or more Before that measure the inner diameter of the sleeve in ambient temperature and after an hour. Slip it after it expands to the required clearance. Check the details of the tolerances and clearances required before you venture into it, as once shrunk fit, one cannot take out the sleeve except cutting.

Govind has good suggestion for heated oil, it is a more precise way to heat sleeve uniformly to the 250-400C temp you will probably want to use.

The other point is be quick and precise with final assembly. I have seen scrap produced when parts are only assembled half way and then lock up when the temps equalize and the interferance locks them in position.

Thanks Govind Rao & Reid.

I will check the interference possible with the shrinking method & understand the retaining force sustained by the sleeve.

Simha

Ried,

There is an equipment known as induction heater used in shrink fitting of bearings. This heater heats the bearings inner race only so fast that there is no time for the heat to transfer itself to the rollers or balls. Hence, only the inner race is heated and the bearing is slipped through on the shaft and cooled fast by quenching in oil. One can look up in reputed bearings manufacturers catalogue.