Comments on: Measurement And Analysis Of Torsional Vibration http://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/ Telling you what you need to know about noise & vibration Tue, 07 Feb 2012 15:32:30 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Peter Mhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-16319 Peter M Wed, 13 Jul 2011 23:47:14 +0000 http://blog.prosig.com/?p=103#comment-16319 One of the issues here (from the initial example) is that you only end up with as many samples-per-rev in your output data as you have teeth on your ring-gear. Add to that the fact that the gear is usually used for something (such as a starter motor) and has physical nonuniformity of the spacing between the teeth due to uneven gear wear which results in a fluctuating count being recorded even under purely constant speed rotation circumstance. (Diesel engines for example usually engage the starter motor in one of two regions of the ring gear the hardest as they stop where the compression is greatest). So to do this accurately then requires a "Mask" be made which characterises these geometric errors on the gear, and which can later be used to compensate for this. A better solution involves the use of a precision shaft encoder (say 720 pulses per rev, giving 0.5 degree resolution ) to get rid of this effect and add angular resolution. One of the issues here (from the initial example) is that you only end up with as many samples-per-rev in your output data as you have teeth on your ring-gear. Add to that the fact that the gear is usually used for something (such as a starter motor) and has physical nonuniformity of the spacing between the teeth due to uneven gear wear which results in a fluctuating count being recorded even under purely constant speed rotation circumstance. (Diesel engines for example usually engage the starter motor in one of two regions of the ring gear the hardest as they stop where the compression is greatest). So to do this accurately then requires a “Mask” be made which characterises these geometric errors on the gear, and which can later be used to compensate for this. A better solution involves the use of a precision shaft encoder (say 720 pulses per rev, giving 0.5 degree resolution ) to get rid of this effect and add angular resolution.

]]> By: huanghehttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-4323 huanghe Wed, 13 Oct 2010 11:12:09 +0000 http://blog.prosig.com/?p=103#comment-4323 I read about the article. I am currently doing a project on torsional vibration measurement using strain gages.what is the relationship of strain and torsional vibration ? I read about the article. I am currently doing a project on torsional vibration measurement using strain gages.what is the relationship of strain and torsional vibration ?

]]> By: Javier Remigiohttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-2180 Javier Remigio Fri, 23 Jul 2010 19:11:48 +0000 http://blog.prosig.com/?p=103#comment-2180 Dear sirs, I am very interested in monitoring torsional vibrations in a vertical mill for a cement industrie. This monitoring must be a permanent monitoring, and I have though to use strain gauges to carry out torsional deformations and to use telemetrie to acquire this type of signals. Could it be your system adecquate as an option for this application? Please answer me privately to my e-mail. Thank you very much in advance. Dear sirs, I am very interested in monitoring torsional vibrations in a vertical mill for a cement industrie. This monitoring must be a permanent monitoring, and I have though to use strain gauges to carry out torsional deformations and to use telemetrie to acquire this type of signals. Could it be your system adecquate as an option for this application? Please answer me privately to my e-mail. Thank you very much in advance.

]]> By: Chris Masonhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-880 Chris Mason Wed, 12 May 2010 07:58:24 +0000 http://blog.prosig.com/?p=103#comment-880 Hi JohnThanks for the comment. That is the sort of real-world information that can prove invaluable to the right person at the right time. And it's one of the reasons we put time and effort into the Noise & Vibration Blog! Hi John

Thanks for the comment. That is the sort of real-world information that can prove invaluable to the right person at the right time. And it’s one of the reasons we put time and effort into the Noise & Vibration Blog!

]]> By: John Millshttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-876 John Mills Wed, 12 May 2010 04:57:15 +0000 http://blog.prosig.com/?p=103#comment-876 On the subject of using angular measurments on a 2000 HP Waukesha Gasious fired cogeneration engine.A high displacement by a connecting rod was found to have been occuring within the burn angle.I found this to be attributed to high Intake Manifold Pressure as a result of the turbocharger control managment system attempting to compensate for lower than required BTU/SCF on digester gas.This can result in connecting rods being tossed through the crankcase if left unchecked.Just passing along an experience with angular measurements relative to an Internal Combustion Engine Cycle. On the subject of using angular measurments on a 2000 HP Waukesha Gasious fired cogeneration engine.A high displacement by a connecting rod was found to have been occuring within the burn angle.I found this to be attributed to high Intake Manifold Pressure as a result of the turbocharger control managment system attempting to compensate for lower than required BTU/SCF on digester gas.This can result in connecting rods being tossed through the crankcase if left unchecked.Just passing along an experience with angular measurements relative to an Internal Combustion Engine Cycle.

]]> By: Jasmin Engelhardthttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-617 Jasmin Engelhardt Fri, 09 Oct 2009 09:56:39 +0000 http://blog.prosig.com/?p=103#comment-617 Hello Mr. Lincoln,I read about your article. I am currently doing a project, on the business & marketing side, on torsional vibration analysis. I really have a very limited knowledge on it so I want to know where can I use torsional vibration analysis apart from Motors and gearboxes. It is said that it can be used to any machine that rotates, could you perhaps provide me an example of other possible machine?Best Regards,Jasmin Hello Mr. Lincoln,

I read about your article. I am currently doing a project, on the business & marketing side, on torsional vibration analysis. I really have a very limited knowledge on it so I want to know where can I use torsional vibration analysis apart from Motors and gearboxes. It is said that it can be used to any machine that rotates, could you perhaps provide me an example of other possible machine?

Best Regards,

Jasmin

]]> By: yanehttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-616 yane Mon, 05 Oct 2009 13:56:45 +0000 http://blog.prosig.com/?p=103#comment-616 I would like to invite you if u have any videos of your equipment to contact me and post free to my <b>Machines Video</b> bloghttp://machinesvideo.blogspot.comthanks! I would like to invite you if u have any videos of your equipment to contact me and post free to my Machines Video blog

http://machinesvideo.blogspot.com

thanks!

]]> By: Ademarhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-613 Ademar Fri, 25 Sep 2009 21:05:30 +0000 http://blog.prosig.com/?p=103#comment-613 Hello James, I am looking for a software to perform torsional vibration analysis of a mass elastic system ( engine + coupling elastic + pump). Does your software do such calculation?Thanks,Ademar. Hello James,

I am looking for a software to perform torsional vibration analysis of a mass elastic system ( engine + coupling elastic + pump). Does your software do such calculation?

Thanks,

Ademar.

]]> By: James Wrenhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-569 James Wren Tue, 30 Jun 2009 11:22:25 +0000 http://blog.prosig.com/?p=103#comment-569 Hello Arkadiy,Thank you for asking a question. Your application is very interesting but it is outside of the scope of this article. We will contact you directly to discuss in more detail. Hello Arkadiy,

Thank you for asking a question.
Your application is very interesting but it is outside of the scope of this article. We will contact you directly to discuss in more detail.

]]> By: Arkadiyhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-567 Arkadiy Sun, 28 Jun 2009 16:54:51 +0000 http://blog.prosig.com/?p=103#comment-567 We are going to repower a Tug boat and looking for Torsional Vibration Analysis for new C18 engine with old trans line. Would you offer your software for that kind of calculation?Thank you in advanse, Arkadiy We are going to repower a Tug boat and looking for Torsional Vibration Analysis for new C18 engine with old trans line. Would you offer your software for that kind of calculation?

Thank you in advanse,
Arkadiy

]]> By: Ivo Dabelichttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-552 Ivo Dabelic Fri, 24 Apr 2009 20:53:41 +0000 http://blog.prosig.com/?p=103#comment-552 I red a published paper (some time ago) by Scientific Atlanta in which they were ademant about the run out compensation especialy when, for example, the readings are taken from large Diesel engine flywheel starting gear due to the "big" diameter? The signal was acquired from permanently instaled magnetic probe used for RPM tacho.... I red a published paper (some time ago) by Scientific Atlanta in which they were ademant about the run out compensation especialy when, for example, the readings are taken from large Diesel engine flywheel starting gear due to the “big” diameter? The signal was acquired from permanently instaled magnetic probe used for RPM tacho….

]]> By: Adrian Lincolnhttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-551 Adrian Lincoln Fri, 24 Apr 2009 08:59:04 +0000 http://blog.prosig.com/?p=103#comment-551 We would not expect to find (first order) runout in torsional analysis when using conventional tachometer instrumentation (such as shaft encoders or hall-effect probes) because they only sense angular motion not radial motion.Adrian We would not expect to find (first order) runout in torsional analysis when using conventional tachometer instrumentation (such as shaft encoders or hall-effect probes) because they only sense angular motion not radial motion.

Adrian

]]> By: Ivo Dabelichttp://blog.prosig.com/2008/10/17/measurement-and-analysis-of-torsional-vibration/comment-page-1/#comment-549 Ivo Dabelic Wed, 22 Apr 2009 17:22:55 +0000 http://blog.prosig.com/?p=103#comment-549 I am interested to find out how do you account for Gear mechanical runout during the torsional analysis? As you know mechanical runout will show as first torsional order (1X)Thank youID I am interested to find out how do you account for Gear mechanical runout during the torsional analysis? As you know mechanical runout will show as first torsional order (1X)

Thank you

ID

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