It an electric motor coupled to the dyno. All the dyno in this case would do is allow the motor to run at its rated load capacity, in this example 700 hp.
The dyno is water brake system. The water is introduced to increase the load on the motor.
Could someone please explain how to interpret the attached power absorption curve?
As an example, if I am trying to run 1800 rpm motor rated for 700 HP. Would I be able to?
I have a gear train with 2 spur gears, 2 bevel gears.
I wanted to know if someone could guide on how to calculate the backlash for these gears and what I need know and do to acheive this.
The train has a one shaft with the bevel gear and spur gear inch apart on the shaft. The spur gear drives...
This time it wasn't cycling 2 times when on rubber or pump head.
It was 1 time and 2 times cycling without the pump head and it did not matter where I measured it radially around the motor.
The initial and final test were both done at the shop.
Initially we had the motor run in the shop...
I have to admit to it also that I am yet to understand completely why it would make the vibration vary between a range.
For now, my theory is that the motor since it's not a synchronous motor, the motor rpm oscillates as well which oscillates the vibration with its natural frequency.
It's a...
I am trying to understand where a backlash is measured in a gear system.
I have a shaft with sun gear on it and it meshes with another shaft having a pinion gear.
Sun gear shat has a coupling to on end which is being driven by a motor. (But this system is uncoupled)
Pinion gear shaft has a...
Sorry for not responding earlier to the thread.
This thread turned out more informative than I expected.
Coming to the conclusion to the original question (OP), I had to do a bump test and low-behold the natural frequency was close to the running speed between 1659 - 1750 and it created a...
After many back and forth clarification queries, here is the true problem. The rotor of the motor is equipped with a fan and moves air axially through the stator. The inlet air temp is 78f and outlet air is 135 F. The material of the core being cooled down to 200 F from 350 f is carbon steel.
By Cycling I mean that the values increase to 0.22 gradually, 0.07,0.075,0.089,0.01.....0.22 and then the reverse happens. It isn't a beat frequency with the way it eventually increases or decreases.
Also, these values are being measured radially.
I am running a vertical motor 4160 V and 1800 RPM unloaded. I checked the mechanical integrity of all parts, bearings housings, stator and rotor. When I measure the vibrations, I get cycling vibration at 2 x the rotation between 0.07 to 0.22 inc/s. Can anyone help understand why this maybe?
Breaker is good, connected to another machine and did not trip.
Yes, suddenly developed and was not replaced.
I changed the EMC board and tried. Next thing after the EMC would be the frequency converter anyways, so I don't think its cost effective to fix that.
I have an ABB ACS800-01 VFD that is operating a 25 hp 460 V AC motor.
Recently I have been having breaker trips as soon as I switch the power supply on. I checked the circuit for any blown marks etc. and it seems fine. Ask for information if you have questions.
Does anyone know why that is?
THANK YOU!
That makes complete sense now. I wanted to follow up on this:
1- The only reason a rubber pad or a flexible base is used is, if the resonant frequency is too close to the running frequency. My question is why then the phase angle changes for vibrations in comparison to with &...
I completely agree with balancing it below resonance.
My question is when we add a spring or a rubber base to detune it from the resonance frequency of the electric motor and balance it.
How does that ensure that the electric motor when installed in the field won't change to a different...
Tmoose
I couldn't really understand the second statement " 1X vibration amplification...."
Vibromera:
I am a novice in vibrations. I am not following on how 700 rpm is equal to 6000 revolutions per min?
Also do you mean maximum rotational frequency as - (60 HZ, for 2 pole 3600 rpm)?
I understand this. It's an odd situation I haven't been on the site so pulling information like if it has fins on the casing or not is not easy. I don't have the nameplate information either. The one they sent is blurred.
I am told for some reason the motor started operating at 350 F and it...
I understand that and its very useful information.
I am still trying to figure out how would one know what the natural frequency of the entire system is?
Let us say I have a Vertical Motor that is going to be coupled to a pump. I dont have the pump.
I fix the motor and I need to balance it to...
Let me know what is wrong with these steps:
Calculate the heat rate using the inlet and outlet air temperature. I will assume any existing CFM AC. Example 4000 CFM
Heat loss rate = Mass flow rate x specific heat capacity of air x Delta T
For this particular heat loss rate calculated we can...
