Flanged wheels ball bearing loads 1

[Algirdas13]

Hi everyone,

I'm planning to use fixed castor flanged wheels (1st picture bellow). The wheel itself has two bearings inside the wheel (2nd picture bellow). The rated load capacity for wheel is 3 tons. For example if I'm gonna load wheel with force that is not symmetrical in a view of wheel, does this mean that I cannot assume that wheel's capacity is 3 tons, but rather 1.5 tons (assuming that one bearing load capacity is 1.5 tons)? The load schemes are bellow.

I would be very grateful for any information.

 

[EdStainless]

When we used flanged wheels we put a gusset on the outside of backet on the flanged side.
This helped keep the wheels vertical.
Depending on how the wheels ride on the rail the load will be anywhere from 75% on the outside to 75% on the inside.
The plate above the wheels and the mounting brackets need to be stiff enough to handle this.
The rest of the frame is usually flexible enough to assure loading of all four wheels.

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P.E. Metallurgy, consulting work welcomed

 

[Orange_kun]

I would have assumed the 3T load rating had some margin for this kind of unequal loading. What does the caster mfg say? The 3T has perfect distribution?

Remember that changing bearing loads, within reason, is only going to affect bearing life. It maybe a case that the bearings, evenly loaded to 3T total, give maybe 10000hrs service. By having your 75/25 loading, you might drop that down to say 5000hrs on the more loaded bearing. I'd find out more from the manufacturer. Or find out the bearing size and do the math yourself. Don't forget to consider how fast this thing has to move, and the effect of any vibration while running or static. And if the rails are in poor shape, that's going to hurt things even further.

I don't trust your FEA setup. I think you're missing the forest for the trees here. I would scrap the FEA and go back to the application details and hand calcs. For example: you don't know how straight that frame is actually going to get welded. Or as others posted, how the container load will be distributed. Also, what's the curvature on the contact point of the wheel to rail? How's that affect the loads imparted on the axle?

 

[Scuka]

Three points define a plane - chances are pretty high that three of your wheels will bear the majority of the load. Unless the fabrication is perfect, it will be difficult to get the load to share over all four casters.

Real world structures are not perfectly rigid.