Anything more than 3 Gauss can be a problem with high speed turbo machinery.
Damage from Electrical Discharge can ruin a bearing in less than 2 weeks of continuous operation
Beware of off the shelf product when mounting bearings in tandem or multiples. You will need to use specail bearings with the high point of eccentic marked on them. Thus will allow you to assemble multiple bearing on a common shaft.
Precautions.
High speed big problem with heat
Grease lube must...
This may have been a plain bond failure of the babbitt lining to the shell. An error in manufacture of the bearing, like forgetting to stress relieve the babbitt layer can result in a bearing which is highly stressed yet passes all tests of manunfacture. The different coefficient of expansions...
This is a vertical motor no doubt? We have been rebuilding motors for over 30 years and the polyamide cages have been a cause of many failures, some catastrophic. In all probability your bearing is oil bath lubrication, or it should be ? The upper bearings are the thrust and the lower bearing...
Perhaps you should out source some of your work, you can not always do it all yourself. Where are you located. We balance spindles for many wood shops and they are very pleased with our work and quality. tolerances are very low and sensitivity of machines is very important. If your spidle is 10...
Pete, I see you are looking at changing greases. Shell have just introduced a new bearing grease for motors called Stamina. Check the details here.
http://www.shell-ubricants.com/products/pdf/StaminaRLS.pdf
Point to note most motor bearings run at less than mimimum load as per the SKF bearing book
IRD, once over sold a kit for making a balance machine I think it was called the B50F. They were soft bearing machines and you purchased from IRD the roller supports and axial restraining brackets, the motor drive belts and the pulleys required to make it all happpen, but that was 30 years ago...
CEC 22.2, 77-95 section 4.1.1
CEC 22.2, 145-1972 section 6.3.4
Read also Hazardous Locations by Bossert chapter 19 Repair Facilities. Chapter 19
Repair and contstruction of motors and generators is contolled and audited by CSA at qualified facilities all across Canada not by Alberta Standata.
Are you working out side ? are your employees working in temperatures of less than 16C. Running high speed machinery with great preciison requires the temperatures to be even right across the operation temperature range.
If the spindles are cold have a heated oil system, if the spindles get too...
It is in the Canadian Electical code that all TEXP motors have as temperature limiting device. Klixon or Thermister. If you do not connect them and there is a failure you have no insurance and all claims against you are valid. An electical contractor could lose his licence for not connecting...
Thanks all of for the valuable info, we are in the process of putting a grounding brush on the rotor shaft in the center at the sheave end as this the most convienient spot right now. They can not shut down now as it is the middle of the ski season and they would strand people on the mountain...
Ductile iron works great especialy if there is room for thermal growth. When the bearing at 1 end is allowed to move, or rotate. The semi-self lubrication properties of iron are much better than steel. There is also consideration of steel hardness. If your housing is too hard you will get...
We are familiar with the NDE insulated bearings on AC drives and both bearings insulated on AC drives for VFD applications.
We have a large 750HP DC motor which has a classic fluted raceway approx 120 degrees of arc on the inside of the outer race. A perfect set of frosted balls and a frosted...
The dual thrust bearing configuration you asked about on the original post is possible. Some, if not most, Dodge Sleeve Oil bearings have 2 thrust collars. These slide on to the shaft and are secured by 2 set screws, 1 at each side of the bearing called "Fixed". These are for minimum thrust or...
You never said if the repair shop tested the motor at full voltage or reduced voltage. The motor would spin quite nicely at 400V and not show vibrations related to high EMF(Electro Magnetic Forces).If the rotor was out of center wit the stator this could be a marked effect. What kind of...
You need to decide what level you need to balance too. ISO 1940 can explain this but it can be difficult to follow. "rule of thumb" If part turns less than 1000rpm G6.3 will work for you, speeds between 1000 and 2500rpm G2.5 will do, faster speed yet G1.0 works OK. You may ask what the heck...
You never said what the RPM required is ? you can forget wound rotor if its 2 pole. Synchronous works very well but the motor you require is only small. Maybe VFD will work for you also. Most induction motors off the shelf are 5.6 -6.3 (name plate code G)You need a code B. Check codes here...
