Thermally Insulating Driveshaft
Thermally Insulating Driveshaft
(OP)
Hi,
We are conducting performance tests on a gearbox and one of the primary ways we do this is by accurately measuring the temperature while in operation. In a test environment we drive the gearbox with an electric motor connected with a steel driveshaft. This motor is having a small but measureable heating/cooling effect depending on the temperature differentials between the two. We want to isolate the motor from the gearbox for test purposes.
Can anyone suggest a material that would be sufficiently strong but also significantly limit the amount of thermal conductivity compared to steel? A composite like phenolic would be sufficiently strong for our purposes, but is there perhaps another material that could even further minimizes heat transfer from the motor to the gearbox and have similar mechanical properties? I considered a magnetic coupling and this is a possibility, but it presents its own challenges such as limited torque.
Thanks for any input
We are conducting performance tests on a gearbox and one of the primary ways we do this is by accurately measuring the temperature while in operation. In a test environment we drive the gearbox with an electric motor connected with a steel driveshaft. This motor is having a small but measureable heating/cooling effect depending on the temperature differentials between the two. We want to isolate the motor from the gearbox for test purposes.
Can anyone suggest a material that would be sufficiently strong but also significantly limit the amount of thermal conductivity compared to steel? A composite like phenolic would be sufficiently strong for our purposes, but is there perhaps another material that could even further minimizes heat transfer from the motor to the gearbox and have similar mechanical properties? I considered a magnetic coupling and this is a possibility, but it presents its own challenges such as limited torque.
Thanks for any input





RE: Thermally Insulating Driveshaft
Mag couplings usually slip, which then generates heat also.
I have seen fiberglass and graphite fiber shafts for transmitting torque, both need to be somewhat larger in diameter than the equivalent steel tube shaft. They are pretty specialty items though, not like you can just order one up "off the shelf" (though if you are handy you could likely fabricate one from catalog-available structural tubing).
In comparison, stainless steel is about half the thermal conductivity as plain carbon steel, and titanium alloy Ti6Al4V another half of that which is about as low as metals get.
Can you use a hollow tube and cut down some thermal cross section that way? Why not just use a longer shaft? Or do you have requirements for torsional flexibility of the shaft?
RE: Thermally Insulating Driveshaft
What size/strength do you need?
There is cold worked SS tube in the market (for aerospace applications).
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P.E. Metallurgy, Plymouth Tube
RE: Thermally Insulating Driveshaft
RE: Thermally Insulating Driveshaft
When it comes to couplings we are always here to help.
WWW.PSCCOUPLINGS.COM
RE: Thermally Insulating Driveshaft
RE: Thermally Insulating Driveshaft
Or Rexnord Omega couplings - you can put the hubs outboard on the Omega couplings and get a nice separation between motor and reducer shafts.
RE: Thermally Insulating Driveshaft
RE: Thermally Insulating Driveshaft