Quote:
Originally Posted by Jake Raby
That single factor is what makes the difference. Every single Bearing Engineer we have consulted with has brought the point up, but we considered it before they did.
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So Jake... if we guess this super secret factor will you confirm if it is correct or not? I have seen Charles Navarro of LN state that he would take this secret to his grave!
I am going to throw out my guess and I am going to bet that I am spot on.
The issue is that in the design of the intermediate shaft the ball bearing application is compromised (not optimal) and the magic number (or constant) that it is compromised by is 20%. We state load numbers for the 6204 bearing based on manufacturer's numbers, but those numbers assume that the inner race of the bearing is turning. In most applications the inner race is fitted to a shaft through an interference fit, the shaft rotates, the inner race rotates, and the outer race is held in place in a fixed housing. Bearing load numbers are based on this scenario.
This is not what happens on the intermediate shaft though. That scenario is exactly the opposite. The inner race is fixed and it is the outer race that is pressed INSIDE the intermediate shaft that rotates.
So who cares if it's the outer race that rotates rather than the inner race? Engineers care because this one little difference has a significant impact on how much load the bearing can take. The general rule that is used in bearing calculations is that the impact is a 20% decrease in load. Decreased load effects calculated bearing life and failure rates.
Is this significant then? 20%? Damn straight that is significant. So how to address this? LN went to a stronger ceramic bearing with a much higher load rating than OEM. But eventually LN went to a plain bearing with significantly different load characteristics altogether.
So what do you say Jake? Do I get the gold star??? :dance:
Kirk Bristol