Bell crank design and thoughts.

[olason]

So I have decided to go with a pushrod, bell crank design, this helps with packaging.



Reading some design threads on bell cranks is they talk about thrust bearings bring used in a interference or press fit into the crank. Can anyone tell me what a thrust bearing does?

And would single shear work? Or would I be better to build clevis ends for the connections? I fear I will need spherical bushings for any misalignment that might happen a the suspension cycles.

[Twentyover]

Thrust bearings carry load along the axis of rotation.

A typical ball bearing carries load perpendicular to axis. If a large load is applied along axis of rotation, usually the cage omes apart and the balls get spat out. Note there are ball bearings deigned to carry thrust loads, I'm simplifying. Using opposed taper roller bearings for instance gives good thrust and radial capability. There are also roller bearings design to handle thrust exclusively.

Single shear works, but requires huger fasteners than double shear.

[19,69camaro]

I am working on the same thing. I ended up using solid steel control arm bushings so I could weld them directly to the bellcrank. Then only thing that moves is the inner sleeve. So far it seem pretty stout. For the connecting rods I used swedged tube and rod ends.

Let me know how yours turns out. I might have to change my plans

[exwestracer]

You will always have some amount of side load on the bell crank as the suspension cycles. The thrust bearing keeps the bell crank in position and prevents metal to metal contact. Here's a set I built for my supermodified:
https://www.pro-touring.com/showthre...rom-roll/page2
Under the aluminum cap is a needle bearing and 2 "torrington" thrust bearings sandwiched on a 1 1/2" X .120 wall chrome moly tube pivot.