Compression loads on bronze bushings

[EspElement]

If I am making a bar link system and I use bronze bushings on the pivot points. If I put force on the shaft momentarily against the bushing (impact load - while link is stationary), how do I calculate the allowable pressure on the bushing area? I have in the past taken half the circumference of the shaft by the width and that's how I determined the area of compression. But I don't think this is 100% accurate. Would the points close to the quadrant take more load then the points 45° to that?

I have searched and looked thru some books and I suppose I'm not researching the proper name of this type of load.

Thanks

 

[dvd]

http://www.buntingbearings.com/data.html

 

[EspElement]

Thats interesting however my force isn't created by rotation, I guess I should have put side load. If I were to put force on the shaft to the side what would be the appropriate way to calculate the compression on the bushing?

 

[dvd]

Make a sketch and post it.

 

[EspElement]

Still incomplete but as you can see the drum will run into the pin stop. It will put pressure on the bushings on the bar links that I have. I want to ensure I'm not putting too much pressure to damage the bronze bushings I'm using for pivoting.

 

[dvd]

A cantilevered pin will have very small contact areas at 180 degrees from each other within your bushing, so you will have very high pressure.

Drums can have quite a bit of kinetic energy. Have you investigated how much energy your stop will need to absorb? Contact the bronze bushing company that was in the link that I posted earlier to ask about your particular problem.

I would also suggest that you consider something like pairs of pallet stops working in tandem.

http://www.norgren.com/document_res...otive/automotive_catalogue/Clamps/101_122.pdf

 

[unclesyd]

Here are two sites that have something that you may want to take a look at. The tension or spring bushings are use in impact load applications where a bronze bushing might be marginal. I have used both types on conveyors.

http://www.connexusa.com/HTML/calculation.html

http://www.vogelsangcorp.com/Usage_Guides/Tension Bushings/Section8.html

 

[EspElement]

These drums will be on gravity conveyor that will be at a few degrees.. guys will push it onto a powered chain conveyor.. As you see I want the pin to come up and hold one drum. Then it will pivot back and stop the 2nd drum behind that position. Then it will pivot back to allow it to come to the 2nd pin again.

I figured max velocity of the drums at 15-20fpm which would be about 3-4 in/s. I usually take an impact force of about 1/20th of a second. So 550lbs/32.16in/s^2 * (4in/s*20s) ~ 1368lb load.

We initially wanted to use one cylinder for this application, but as I think about it more. Simple is better sometimes and with all those joints and moving parts, it might be best to go with 2 individual stops as you suggested DVD.

I may not go with this idea, but definitely something I'd like to know for the future.

Thanks uncles for the post, That appears to be what I'm looking for, when I get home ill get more time to look at it.