motor bearings

Not unless you register and explain yourself more clearly.

The design usually require third party products to comply with minimum specifications.

The procurement officer at manufacturing then secures a supplier to fill all needs, hence the great number of the same parts.

Unfortunately nothing remains static and the specifications, product, supplier or agent may change over time.

A few extra parts may also be required from time to time.

Errors may also occur. (wrong bearings in a bin)

What you should do if discrepancies are found is to compare specifications and raise hell if inferior products are found. (the manufacturer may thank you for that)

What kind of motor what kind of bearings?

I'm assuming you're saying the drive end has a different bearing than the non-drive end does? The usual case is either that the NDE is also a thrust bearing or that the DE is deigned for a radial/overhung load.

TVP45 is right but seems to be in a hurry.

And Guest-unless you register and ask with clarity-you do not deserve any reply.

Still let me repeat TVP45:Non Driven End can be Radial. Radial ball bearings already has 40% Thrust capability.

Driving end takes the bash and need to take all BENDING, IMPACT loads .Ideal should be a Cylindrical Roller.

If Guest found both ends same--well there are Good/Average/Sloppy/Poor designers !

"TVP45 is right but seems to be in a hurry."

You should try typing long answers while handcuffed to Tony Curtis!

Any motor must have a thrust bearing. Think of all possible loads a standard motor may be subject to. Loads connected directly to the end of the shaft may be winches (one extreme, purely radial loads cantilevered) or actuator screws (the other extreme, purely axial loads). Usually one bearing is one that can handle both radial and axial loads (like a deep-groove ball bearing).

The other bearing may be different because it carries only a radial load or it may be the same because using two of the same bearing (one fixed, one floating) gives greater economy i.e. buying double the amount is cheaper per bearing. Less stock may be held (because you only need one kind), less diverse spares are easier to keep, the motor may be one of several different types sharing the same bearing. The list goes beyond the purely functional to what's practical. It all depends on the manufacturer's choice.

"Any motor must have a thrust bearing."

I disagree - but maybe that is only a matter of terminology. Not all motors ARE standard or general-purpose. We use a lot of small motors designed only for use with gearboxes from the same supplier. They have a planetary first stage to avoid any side load. The gears are straight-cut, so do not induce axial thrust loads - like your winch example, but much smaller. Instrument ball bearings with a VERY light press-fit on the shaft are more than adequate to carry the axial load from, say, use with the centerline vertical, even though they are not rated to carry any thrust load. Probably the largest side-load is due to the fine spring-wire brushes - very low single-digit grams, at most - and they're balanced against one another. Encoders, when used, are non-contact types (optical or magnetic).

You are right - in a way. There are motors that have double worm gear reducers where the worms are opposite handed, meshing with worm wheels and pinions that then mesh with the same final gear wheel. These motors are used in the auto industry and have no thrust bearings at all. However these are special cases. I would not consider building a motor with no axial guide, even if only straight pinion teeth are used, simply because there are electromagnetic forces that may produce axial loads! Connect any motor with a bit of axial play in the bearings and watch what the shaft does.

Some compagny order special bearings (in or outside diameter a few tents of mm different) to avoid that standard bearing could be used and or replaced and service could be provided outside the service net.

Some compagny order special bearings (in or outside diameter a few tents of mm different) to avoid that standard bearing could be used and or replaced and service could be provided outside the service net.

I'd like to see these special bearings.. Where did you get this info?? crackerjack box?

Vehicle manufacturing does this all the time.

Bearings that are ONLY manufactured for their spec. and you CAN'T buy them over the counter.

Also in drive belt and timing belt applications you will find that a brand of timing belt will manufacture a particular length only for that particular manufacturer. You cannot buy that belt yourself direct, only from the dealer of that car or bike brand.

Protective design is found everywhere and basically stinks until you compare the prices of the "next best thing" and you find that what you thought was exorbitant and prohibitive pricing is actually not that bad.

I tried a HD drive belt from Gates with a certain profile and tooth dimension and found they did not make that one for normal sales, only for Harley Davidson. When I asked the price for the one under and the one above I found the price from Gates direct was way over the price that Harley charged me direct for the correct one.

Spending power talks in large numbers.

I agree with # 6 and many others.

The following is based on 50+ years of maintenance experience.I ain't smart,but I learned not to keep mashing the same finger over and over to see if it will hurt again.

Sorry guest.Your comment shows a very limited experience in this field.This has been a very common practice in about every way that it can be done during my 50+ years of maintenance experience.I have found it on nuclear submarines,weapon systems,major brands of farming equipment to modern industrial and chemical plant equipment.It is all around you,over you and under you.You eat,sleep wake and many folks lives depend on equipment built by manufactures that follow this policy.

Asking is the attempt for knowledge.

To ridicule is to expose your self to others in many ways.

Follow your Crackerjack box piece by piece to the tree in the forest.You can find many examples of what you questioned along the way.Being I have planted trees,grown trees,harvested trees,hauled trees,worked in a wood yard,pulp,paper,bag and box plants,I do know that your Crackerjack box is a result of equipment manufactures that practice what you question.

Also in this 50 years I have found that the "Crackerjack box" theory is often used by the ignorant that assume others are as or even more ignorant than they .

We are all ignorant in many ways.Until we learn we are ignorant,we can not learn.How many attempt to learn what they believe that they already know?

This practice and the parts are normally called "Dealer Items" in the parts supply systems of the world.It was a world wide practice.Unless it has been changed very recently,it still is.My local Auto Parts store recently told me something was a "Dealer Item".

I have found the wrong bearings on new,used,and rebuilt equipment.New bearings that were bad.Also supplied by parts suppliers.This is why there are recalls and notices issued.Many reasons have been given on here.I have even gotten the wrong bearings and info from a equipment manufacturer.Also marked wrong from bearing manufactures!

There can be many answers to this question and all who are open minded are learning from all.It is amazing what all you can learn from a bearing,or even a little box if you wish.

I am here to learn and to hopefully help.I see most on here are for the same reasons.We can even learn from the ones that aren't.

I see many possible answers to the original question.I see this from practical experience.Not smart.Not formally educated,not gifted.I was just taught to SEE when I looked!

Thanks,peewee

Hi guest

I worked as a design engineer for different multinational company's

This is common practice for expensive equipment which is build in series.

>>motor with same drive bearing and end bearing with same number....

yeah, that is possible.

>>in some other motors i find it diffrerent....

What is different? The end bearing vs. the shaft bearing? The number of both bearings?

As another poster mentioned in the first case the bearings are different as one is designed to handle a side load.

In the latter case you will find that many manufacturers will use different suppliers over the course of a product life, especially for commodity products like bearings. Once they have a spec they buy for the lowest price. So the vendors will change and the part number will probably change too.

I would suspect it has a lot to do with the application it was intended for and whether or not it was meant to change rotational direction.