Shrink Fit - Part Hardness Problem
Shrink Fit - Part Hardness Problem
(OP)
We are trying to shrink fit a splined bushing onto a rotating shaft. To be able to transmit the application torque thru the shrink fit connection, both shaft and bushing are machined to very close tolerances.
The bushing needs to be heated as high as possible (no more than 300C/570F) to achieve the needed bore expansion. However, doing this for any reasonable time will result in degradation of the hardness of the spline teeth! We thought of quenching the bushing after it is installed on the shaft to restore part of the teeth hardness. But we are unsure if this really helps. Does anybody have any experience with such an application? Can we achieve the needed quenching effect using a water bath?
Regards,
The bushing needs to be heated as high as possible (no more than 300C/570F) to achieve the needed bore expansion. However, doing this for any reasonable time will result in degradation of the hardness of the spline teeth! We thought of quenching the bushing after it is installed on the shaft to restore part of the teeth hardness. But we are unsure if this really helps. Does anybody have any experience with such an application? Can we achieve the needed quenching effect using a water bath?
Regards,





RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
PeterCharles,We cannot support the other end of the shaft due to the nature of the assembly.
Foets, we are concerned that freezing the shaft might result in humidity being introduced into the connection. Is that a legitimate concern or are we being too cautious?
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem
Mike Halloran
Pembroke Pines, FL, USA
RE: Shrink Fit - Part Hardness Problem
You may even be able to press fit the spline using the flange bolts. In this option you don't even need to turn the 30 mm diameter just build the spline with one end closed. Through this side drill for few bolts. At the end of the motor shaft drill and tap threads to accommodate the bolts of the flange. Using the bolts you can press fit the spline on the motor shaft. You may need to make the motor shaft free length in the amount of the flange thickness.
Third and simpler option is to use the same spline. drill and tap few threads at the flat edge to the motor shaft. Use a disk with a little bit larger outside diameter than the spline outside diameter. Drill holes for bolts/screws to accommodate the threads in the flat edge of the shaft. Now you can push and press fit the spline on the shaft using threaded shafts and nuts where the threaded shafts length is larger than the 135 mm of the spline plus the disk thickness plus the nut thickness.
RE: Shrink Fit - Part Hardness Problem
Dry ice is a method of cleaning electrical switches so I am pretty sure that humidity is not a concern, but you may want to ask the electrical gurus to make doubly sure.
FOETS
BEER: It's not just for breakfast anymore.
RE: Shrink Fit - Part Hardness Problem
RE: Shrink Fit - Part Hardness Problem