Sperical washers static load limit 1

[Verkstad]

When i a am looking at a sperical washer and a conical seat according to din 6319 The reseller define the load capacity in terms of static load see example below. What does that mean? Does it mean it can handle larger dynamic forces? Or that it cant handle a varying load even if it is below the preload?

https://www.halder.com/PM/Standard-...hers/Spherical-Washers-Conical-Seats-DIN-6319

 

[Jboggs]

"Static load" means that the direction of the load does not move or change. It does not refer to a changing amount of load, only the direction of the load. It is a washer assembly, not a bearing. That means it is not intended for applications which involve relative motion between the two parts.

 

[desertfox]

Hi Verkstad

My interpretation of the static load is that you cannot load the washer beyond that stated load capacity, so let’s say you could preload the bolt beyond that stated load capacity then you damage the washer. It doesn’t relate in anyway to a dynamic load to my way of thinking.
What’s the application in your case other than you might have unparalleled clamping surfaces?

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Verkstad]

It is for holding a bracket where you may get some load variation. I am thinking about having a cylindrical pinn to avoid any shear forces.

 

[desertfox]

Hi Verkstad

I can’t see any reason why you can’t use the conical washer and seat, it’s the bolt and it’s preload that’s important even if it see’s a varying load and provided the load doesn’t exceed the stated limit it should be fine. The application for the spherical washer and seat is

https://www.halder.com/ix_pim_asset...ung_png/all/IM0004489_AnwendungsZeichnung.png

The clamp might see a variation in load depends on the how much that compression spring gets compressed during operation.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Jboggs]

Will that load vary in direction, or just in amount? If only the amount of load varies (and not its direction) then you're good to go as long as the maximum load is less than the rated load. The word "Static" just means that there should be no relative motion between the two parts of the washer while they are loaded.

 

[Verkstad]

There are load cases where the direction could be different but the large load would be in on direction. But with a cylindrical pinn the load direction should be in one direction.Since the cylindrical pinn takes the shear force.

 

[desertfox]

Hi Verkstad

Can you provide a sketch of your situation, I cannot visualise what you are describing.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Verkstad]

I am on my cell phone so can't paint. On monday i can send a sketch.

 

[desertfox]

Thanks Verkstad

Much better to see a sketch or diagram.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Verkstad]

Hi!

It hit me that i could draw and take a picture . I hope it is understandable. It is a bracket inside a square beam. 1 represent bolts with a sperical washer 2 represent dowel pins. I have shown 3 loading cases.

The idea is that the dowel pins take the shear stress and the bolt the normal stress hence the force direction is constant.

 

[desertfox]

Hi Verkstad

Thanks I understand your sketch, I can see that the dowel pins would or should take the shear for the load cases 1 & 3. The bolts would take the tension when load case 3 is applied. I would turn the dowel position through 90 degrees and place them to the outside of the spherical washers as this would help to achieve good alignment of the bracket.
I can’t see why you need the spherical washers unless there is some irregular face that the fastener head sits on, if that is not the case then I would just go with a bolt and a plain washer.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Verkstad]

Thx for the replies . I may need a shime with a angle to align the item that meet the bracket, but i am not certain, The spherical washer will only be used if needed.

 

[desertfox]

Hi Verkstad

You’re welcome

The load cases that are on this bracket, are they or can they be applied simultaneously? If that is the case then the bolts need to sized accordingly and with a suitable preload.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Jboggs]

After seeing your diagram I don't understand why you are using spherical washers. Why would standard flat washers not work? Normally spherical washers are used when the axis of the bolt thread will not be perpendicular to the clamped surface. But I don't see any evidence in your diagram of that condition. Am I missing something?