Test measurement of torque pulse on tractor engine
Test measurement of torque pulse on tractor engine
(OP)
I've been asked to measure torsional vibration due to the torque pulse of a two cylinder engine on a tractor. The idea is to isolate the effect of torque pulse and determine the effectiveness of a torsional damper in reducing this effect. I'm visualizing the accelerometers 180 degrees apartand measuring the circumferential vibration. Does this sound right?
Has anybody done this before? I link to a paper / test method would be helpful.
Thanks in advance for help.
George
Has anybody done this before? I link to a paper / test method would be helpful.
Thanks in advance for help.
George





RE: Test measurement of torque pulse on tractor engine
Your accelerometer idea will work, but you'll need a way of getting the signall off the crank to your instruments. Slip rings are noisy, wireless may be a bit big.
Interesting stuff, TVs. The bible is by Kerr-Wilson.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Test measurement of torque pulse on tractor engine
I use a strain gage telemetry system for measuring torque and torsional vibration.
www.binsfeld.com
I also use an optical or magnetic encoder with a frequency to voltage converter to measure torsional vibration as angular velocity. The engine flywheel with starter gear teeth may serve as a target for a magnetic sensor. This may not be the best location, since it is on the engine side of the torsional isolator/damper.
The choice of measurement method, sensor type and measurement location can depend a lot on access to the drive system.
Walt
w_f_strong [at] msn [dot] com
RE: Test measurement of torque pulse on tractor engine
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Test measurement of torque pulse on tractor engine
RE: Test measurement of torque pulse on tractor engine
M
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Dr Michael F Platten
RE: Test measurement of torque pulse on tractor engine
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Test measurement of torque pulse on tractor engine
I like the f/v and FM approaches, but I've done it "digitally" too when timely acce$$ to those methods was not available - just record a data stream of the optical encoder output (volts vs. time, or 1's and 0's vs. time) and post-process with some c/c++ code to find apparent position, speed, and angular acceleration vs. time. Big whopping data files, but storage is cheap. Writing the code was painful, but once done it came in handy quite often. Nowadays, with fourier analysis built-in to Excel, it would be a bit easier yet.
RE: Test measurement of torque pulse on tractor engine
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Test measurement of torque pulse on tractor engine
RE: Test measurement of torque pulse on tractor engine
Why do it the hard way like that? I was young, there was no money or time, and... well, it worked.
Still, I like the FM approach and the f/v approach, these would be simpler and probably yield better results. I like even more the fact that other, much brighter people like Mike and Greg have used similar techniques, for good reasons. I once tried to convince people at another job that the technique would work (and it would have) for a very high-rpm measurement where it was questionable if slip rings or wireless techniques could be made to work due to the imbalances the devices would impose on the system.
RE: Test measurement of torque pulse on tractor engine
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.