Rotary Cutter Shear Bolt and Slip Clutch

[hydro2]

I bought a used brush hog and it appears to have both a shear bolt and a slip clutch. I figured it would have one or the other. Am I correct in that assumption?

Thanks!

 

[Willl]

I would think so also.

Could put a high grade in place of the weaker shear.

 

[hydro2]

Thanks for the response. I will take some pics of it.

 

[hydro2]

As promised a pic. Sure looks to me like a shear bolt and a slip clutch.

 

[RickB]

Could be the machine was built with a shear bolt and someone added a slipclutch. Could be the PTO shaft is attached to the slipclutch with the pictured bolt and also a key, in which case the bolt isn't a shearbolt at all. At any rate, given the slipclutch is present, use the a grade 8 bolt, or if metric, a bolt with 10.9 on the head to affix the shaft to the slipclutch. You don't need for the bolt to shear when a properly serviced and adjusted slipclutch is present.

 

[MikeD74T]

DON'T use a grade 8 bolt. If the slip clutch fails a shear pin still provides protection. If the shear pin fails the slip clutch isn't working properly. Either way why not have double protection ???? MikeD74t

 

[RickB]

DON'T use a grade 8 bolt. If the slip clutch fails a shear pin still provides protection. If the shear pin fails the slip clutch isn't working properly. Either way why not have double protection ???? MikeD74t

Tens of thousands of rotary cutters are protected by slipclutches alone; when properly maintained and adjusted, they work flawlessly. There is no need to be inconvenienced by a broken shearbolt when slipclutch protection is present. If the OP plans to rely on a shearbolt, he may as well remove the clutch.
At any rate, there is no clear evidence that the bolt acts alone in securing the yoke to the shaft.

 

[Baby Grand]

As promised a pic. Sure looks to me like a shear bolt and a slip clutch.

View attachment 247171

Does that bolt go thru the center of the splined shaft, or just kiss a slot in the side of the splined shaft? The latter is meant for axial retention, not shear protection.

 

[hydro2]

Does that bolt go thru the center of the splined shaft, or just kiss a slot in the side of the splined shaft? The latter is meant for axial retention, not shear protection.

I guess in will pull the bolt and see if the shaft is retained by the bolt. Thanks for all the input so far.

 

[RickB]

Does that bolt go thru the center of the splined shaft, or just kiss a slot in the side of the splined shaft? The latter is meant for axial retention, not shear protection.

If the shaft is splined, it matters not where the bolt passes, it is NOT a shearbolt. The yoke can't rotate freely on the shaft if both are splined. :confused2::confused2: