Scoggsgurra - I remember your comments during this thread,, and proven to be right.
I did want the clutch changed in the early period of this vibration issue as it was common to both the motor and Sag Mill drive and high vibration was at both ends of the drive train. But informed nothing is...
I did believe and was convinced that the 2400 cpm frequency was coming from the motor. I also received expert advice it was the motorEven now I cannot relate the air clutch to this 2400 cpm frequency, only the cracking in the drum effected shaft stiffness and contributed to a torsional...
Hi
I apologise for not replying to this thread for some time as I have been off work for some months now with a sickness but on the mend.
While I was off work there was work done on the Sag Mill. They bought in specialist to carry out work and inspections.
They replaced the infeed trunnion...
The original value was 4.6mm bottom 1.4 top 3.9mm 2mm side to side. Final gap all around 3mm +- .12mm. We tried to get the gap spot on but were bolt bound and could not move side ways. This is one step with an improvment but have to keep going.
The other main issue is the pinion. We have had...
Hi
it has been awhile but the vibration level is still high. I did correct the exciter level and we did get a significant reduction in vibration amplitude
from over 30mm/sec to 18mm/sec.We monitor the vibration levle evey morning and will inform you is we get any additional reduction
The...
I am on leave but getting no reaction from site on carrying out a full electrical inspection on the motor.
I have contact with the GE OE and he is recommending everything to be checked on the motor connections ,mega etc.
I also asked about running the motor un synconised to try and rule out the...
I have that in mind to check the axial clearances on the bearings when we locate magnetic centre.
My experience before working here was you have a gearbox to motor drive for speed reduction. The motor rotor can float as you have a grid type coupling. But again you have to check the mechanical...
Hi I am actually on leave but have vibration data sent to me twice daily. They keep running the Sag Mill and we know the vibration levels are too high.
I have read other forum comments and now looking at magnetic center and this forum would of discussed this many times
There has been an...
We looked at the clutch and it has 20 pads elements. Sounds good to take vibration data without excitation. It could indicate the origin of the mystery frequncy
Other reapirs have been sheduled and we must fix what we have found, See if there is a difference and move on from there.
The biggest...
Skogsgurra (Electrical) I have made the recomendation as you have mentioned and totally agree it has to be done. As mentioned skill electrical is limited on site and actually within the country. At this time looking fro the right paople to carry out these inspections
Thanks again
Just to share some addtional information. There are slight different in vibration levels day to day as there can be more Tons/hour and can be more or less steel ball charge. So we have a change in mass and a slight influence on the amplitude
These are coments below from a leading vibration...
I tried to answer this post a few days ago but did not load up, Did not get a chance to check the number of stator coils etc.
The clutch has an axial locking device which will limit end float. So possibly the motor can be held off magnetic center
The 2400 CPm frequency can be measured and...
I will check the end plate on the motor non drive end today.
I actually got some good data on the motor on 9th january.
When the motor is uncoupled or with an air clutch disengaged it is running at very low amplitudes
Motor Non Drive End
Horizontal plane .39mm/sec RMS
Vertical Plane...
The axial reading today on the motor in the axial direction was 27mm/sec RMS. it varies i beleive due to load in the Mill.
This is the worry the readings are true values in MM/sec RMS. I have checked with another instrument and gear specailist agreed with our vibration readings comapred to his...
The drive train is described as follow
5,500 KW motor 50Htz. The motor is Sybcronis 200 RPM. The motor drives the pinion shaft directly through an Eatons Air Clutch
The Pinion drives the Mill through a large girth gear. The pinion has 21 teeth and the girth gear has 376 teeth.
On the Eatons Air...
To Skogsgurra I apolagise . Very frustrated as the issue is one it hard to locate
But Skogagurra is correct and correct what find. Yes the exciter air gap should of been corrected on the day. We should also check magnetic centre. We have an air clutch locking device and should make sure that is...
Skogsgurra (Electrical) 14 Jan 15 07:01
[highlight #EDD400]I wish that you stopped clinging to those 2400 CPM[/highlight]. I do not appreciate these sort of comments. I am asking for advice not comments like this
I am not sure what industry you work in but not mining. Your suggestion just fix...
As mentioned one of the items found is the air gap on the exciter is well out of specification. I checked with the OEM and the minimum exciter air gap should be 3.2mm. Here we have 1.65 mm top 4.7mm bottom side to side 2.7mm 3.9mm
i have taken vibration readings with the motor disconnected from...
We had a shut down yesterday to check the pinion drive end bearing and the motor journal (white metal bearings). What was noticed is the air gap on the exciter was very uneven. 1.2mm top and 4.5mm bottom and out side to side but not as bad. We did not have time to correct and told to back on...
From your experience can the PdMA pick up a fault . I mean could we gain anything. Will also take your advice and on counting the stator slots. On a 30 pole motor what number range would expect and could it relate to the 2400CPM frequency. Below is some information from the OEM,, anything there...
