SomptingGuy- Can you elaberate on, "This is caused by the sudden combustion of fuel that has already evaporated when combustion starts", more so I fully understand it? What is evaporated? Is it not a mass of atamized fuel that explodes when compression creates heat enough to ignite?
SomptinGuy, Thanks for the reply but I am still confussed. Is it combustion noise or injector noise.
ivymike, Boy did you hit my hot button. I am a vibration technician that collects and analyzes data from various industries. They are primarily motors, fans and gearboxes. I would really like to...
Can someone explain where the clatter noise on a diesel engines comes from? I always thought it was from the injection pump(hydraulic noise). I believe the newer trucks have electronic injection and the noise is still there.
I have noticed sidebanding around turning speed and it's harmonics with peakvue. On 1800 rpm equipment the sidebanding is around 3Hz. On 3600 rpm equipment the sidebanding is around 5 Hz. I see this on motors, pumps, fans etc. It is not cage or slip pole. Any suggestions would be appreciated? I...
Can any one explain how a harmonic dampener on a V8 works? Is it tuned to the natural frequency of the crankshaft? Does it dampen the torsional twist of the crank from the power pulses? Why does one dampener work for cast/steel cranks? How can sprint car motors run with out one? Thanks!
Thanks for the info guys! I was hoping I could use an acellerometer, put reflective tape on the dampener, use a tach and collect a high resolution spetrum. I was hoping the torsional vibration would show up as side bands around tach sensed turning speed. Is that just wishfull thinking?
I have CSI 2120 vibration equipment. A customer wants to know if I can take torsional vibration data on their Walkasha deisel engine. Can any one tell me what he is looking for and can this be done with an acellerometer and tach?
Have you done anything with the gear box yet? I am trying to have my customer rebuild his gearbox due to bearing faults. They will be inspecting it soon. I want to do some resonace testing of the shafts and box at that time. I will let you know if I find any thing interesting.
My best guess is that the issue resonance is from the input shaft. I have not tried to calculate the shaft natual frequency or harmonics. I base my decission on the fact that the highest amplitudes come from the input shaft sensors. the amplitudes are lower at the other positions on the gearbox...
I have a primary gearbox with about the same dimensions at a steel mill drving a 10 stand rod block. It also has a resonant frequency from the input gearmesh at around 380HZ of 1 IPS and drops to .1 IPS at other speeds. This unit only runs at that speed a few time a year so it is tolerable. I...
If it was a bearing defect(ball spin I presume)it will travel up the spectrum as speed increases. If it is electrical it will stay at 50hz. In DC motors I have seen increased line frequencies with power isues. Like loose connections and failing SCR cards. I have also seen line frequency issues...
