Bracing

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Is the mounting spot on the gear box capable of dealing with the load in tension as opposed to compression?


I would be more inclined to find out what is causing it to bend than swapping its location.
 
ptonsparky said:
Where should the bracing be? The gear reduction and the motor are supported by the load shaft. 25 HP. The existing location has resulted in bent threaded rod at the turnbuckle for one customer and shifting of entire assembly by about 45 degree at another. Is there reasoning for it being installed as it is now?
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Is your torque arrow the torque applied to the load shaft (the direction that shaft rotates) or is it the reaction torque on the assembly (opposite to the shaft rotation direction)?
If the latter, then I would agree that the current location puts the rod and turnbuckle in compression, which is not what it was designed for. The turnbuckle should be OK either way, but the rod is going to bend, especially since the starting torque will be much higher than the running torque.
Also, the direction of the rod should be along a tangent to the circle centered at the load shaft. Any other angle will require higher tension or compression to resist the same amount of torque.

And, as mentioned, the best place for the brace would be at the greatest possible distance from the center of the load shaft, namely at the other end from where it is currently attached.

What about braking though? Does the load coast to a stop of does the reduction gear cause it to be braked by the motor when power is removed? That would cause torque in the opposite direction during braking and require a brace for both directions.
 
iwire said:
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I would be more inclined to find out what is causing it to bend than swapping its location.
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Brace not tangentially aligned with applied torque. Alignment isn't as critical for a brace under tension.

I also agree with zbang that the best attachment point for the brace is the point on the gear box furthest away from the torque axis.
 
zbang said:
I think you're right, the brace comes from the wrong direction; should be from the left. Any reason to have only one brace? I'd put it to the top of the GB (from the right).
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The provided location for bracing is at the bottom as indicated. IIRC it has a rubber bushing for minor shock.

iwire said:
Is the mounting spot on the gear box capable of dealing with the load in tension as opposed to compression?


I would be more inclined to find out what is causing it to bend than swapping its location.
Click to expand...

The mounting spot does not appear to be designed for one over the other.

This is related to "Thunk Thunk" and what caused this has already been addressed.

Just trying to figure out if I am wrong or if this is a poor practice on the part of the installers.
 
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