Bearing shaft adjustment

3D Design Assembly
1

Hello everyone,

I am currently doing a bearing assembly on a shaft and I asked myself the question of how I can determine the play on the shaft. I was able to understand that for my situation a game in H6 would be enough

Here are the details of my case:

image
image743×634 94.8 KB

I have two bearings that are aligned to place an axle. The objective is to rotate the upper axis to deposit a product.

So I would like to know if a game in H6 is enough and how I should mention it in my 3D modeling and/or on my plan.

Thank you in advance for your help.

Bearings PDF:

23800-101203712.pdf (489.2 KB)

2

Hello.

Well, in fact, the problem is that your adjustment depends on two things:

  1. Adjusting your bearing
  2. what you want to do with it. If you're lucky, you sometimes have the recommendation of your supplier

And there, you don't have the adjustment of your bearing... So, it's a bit complicated to be able to guide you (no pun intended)

3

No matter how much I search on Norelem, I can't find the fit on their site. Would there be a supplier that allows you to have 3D models of the parts while having the necessary information?

4

Hello

The manufacturer of your norelem bearing is FAG (Shaeffler)
6301-2Z.pdf (345.3 KB)
You have to look at them for more information on the assembly, the play will depend on the forces applied to your bearing, among other things.

Otherwise a bearing is 3-4 dimensions, it's quickly modeled :wink:

1 Like
5

Hello
I am not a specialist in the field, but I stick to the indicated tolerances
on the attached abacus.
tolerances_et_alesages.pdf (106.1 KB)
Kind regards

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6

Hello

For the bearings, you have to look on the FAG (Shaeffler) website directly to know the quality of the shaft according to the load (internal ring tightened on the shaft for the time being since the outer ring is " free ").
Unless I'm mistaken, we must be on p8

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7

Hello

A priori, the components that best meet the application you are considering are ball or roller rollers, with or without an axis.
Compared to conventional bearings, their outer rings are thicker, and possibly domed to avoid overloads due to edge effects.
By choosing a version with an axle, you avoid the questioning of the adjustments...

image
image1131×856 225 KB

The SKF page by following this link details these components. Similar products are available from other manufacturers: FAG, INA, NTN-SNR, sometimes called " cam rollers ".

Kind regards.

4 Likes
8

The efforts applied are very low. The mass of the screw is 5 kg, so you can take 50 N for a single bearing, even if it is positioned on two, just to be safe.

9

Great, thank you!

That was one of my questions too; to find out if there were more suitable bearings for this kind of use!

10

Apart from the two bearings visible in your image, how is the shaft guided?
I would have imagined four pebbles to guide him properly. And even six...
You only mention the weight of the tree. The elements responsible for setting it in motion (gear, belt, etc.) would have no action on the rollers?

11

Mounting with a mallet or press!
It's all in the GDI on the page of shaft and bore tolerances! :grinning:

3 Likes
12

When you talk about the shaft, are you talking about the axle in black or the shaft that will be used to hold the bearing/rollers?

image
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If it's the black axle, it's an 850mm long screw that weighs 5kg. It is one of our operators who will position it on the 4 bearings.

For information, they are already stored with similar supports in the same place. They are wide enough not to warp under their own weight.

image
image1366×261 38.1 KB

13

I was talking about the black axis.
I understand better by looking at your last image.
Indeed, if it is just a question of coating the axle with a product by a "manual " rotation, only the weight is to be considered.
Since the forces on the rollers are very low, ordinary ball bearings are more than sufficient.
If they are immobilized axially on the shafts (circlips...), a just sliding adjustment is suitable (g6 or h6). Otherwise, a slightly tight fit may be enough to keep them on their shafts (m6).

14

So, an assembly with domed rollers is not necessarily useful?

This means that in the drawing that I am going to make, I mention in this way:

image

16

In general, the part is dimensioned on a plane of the axis alone. Not on the overall plan.
In addition, how is the axle fixed on the clevis?
If it is by welding, the M6 bore machined before welding, may deform when welding the shaft.
And also how the bearing is held (assembly in mallet force, press...) How will it be held in place (Circlips, lock washer...)

17

@sbadenis, this is not wrong in itself. There are also wide plans where you put the two dimensions of your set Ø12m6/H?

Otherwise, a little anecdote about this tolerance.
A feedback from the workshop that did not include the dimensioning: he had to make a smooth Ø12 axle or an M6 thread? no because well, it's not the same diameter anyway!!
I remained silent in front of this question, not knowing how to answer in a non-passive/aggressive way.
Here it is, telling the story of my life in [OFF] mode

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18

If I make a Ø12m6/H7 dimension for example, it's to size the bore and the shaft, right?

19

Yep, you characterize your game in your assembly.

I'm not a big fan of this rating, but it at least allows you to check that you've validated your editing game!

20

But in my situation, I don't need to mention the rating for the bore?

21

Agree with @sbadenis : definition dimension to be made on the drawing of the axis alone.
And detail of the frame/supports/shaft assembly of the bearings to be specified.
Little effort on the assembly, no tight precision constraint apart from the diameter of the bearing seat, I would be tempted by a screwed assembly. Which can solve the axial bearing/shaft connection by the way.
And why not a single support receiving both axes...
And in this case, is the bottom plate essential?

As for the tolerance indication m6, if it poses a problem of interpretation, it is always possible to replace it with the corresponding numerical interval.
And of course, no mention of a rating for the bore, it is the manufacturer of the bearing who manages...

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