Friction Torque Limiter

[Spanner]

IMO slip clutches are only for very frequently used equipment. All others, especially weekend warriors, are better off with sacrificial shear bolts. Those only need maintenance when they break and it only takes five or ten minutes to replace in the field once you've done it a few times

Slip clutches are possibly more accurately called a Friction Torque Limiter. As can be appreciated, the device limits the maximum amount of torque applied to the implement through the PTO shaft.

It is a 'slippable clutch' yes.

Anyway, I just wanted to suggest that Slip Clutches and Shear Bolts have differing functions.

The SB protects the drive-line from 'shock loads'.

The SC protects the drive-line from 'progressive over-loads'. That is why it is adjustable.

I don't see 'adjustable' shear bolts. Just saying...

Regards,
:wrench:

 

[IslandTractor]

Maybe thats why Iv been able to run mine for 50+ yrs with no such maintenance. Outside storage rain shielded.​

When mine starts slipping noticeably I just tighten it. 3 or 4 adjustments over 50yrs. But we definitely do stuff that cause micro slipping so the clutches get a modicum of automatic scrubbing.

So long as you use an implement with a slip clutch regularly there shouldn't be much need for maintenance. Many slip clutches are installed on bush hogs that sit outside and are unused for months at a time. That's where rust can "weld" the disk so it doesn't slip properly. It the first time such an impact occurs it simply breaks the "welded" plate free then all is good but if the impact doesn't break the disc loose then your gearbox and tractor PTO get the full impact.

I have a slip clutch on my bush hog and spend 45 min each year fiddling with maintenance so I can use the mower occasionally. I'd trade the dam thing for a simple replaceable shear bolt in a heartbeat.

 

[Spanner]

Yeah that sounds like a real pain..... however the tiller only came with a slip clutch. The rotary mower I have has a shear bolt. Easy enough to understand. Bolt breaks, put in new one. Done and done.
.

Easy enough to visualise too.

Different applications for differing drive-line protectors.

:wrench:

 

[JRobyn]

Once you arrive at a suitable spring tension for your needs, one of these - Empire 6 in. Pocket Ruler-273 - The Home Depot - makes it easy to reset it to the same place after "maintenance". Just make note of the length of the springs and tighten the same each time.

Don't believe that keeping a slip clutch under cover will prevent plate rusting. My BushHog is made with a flip-up clutch cover, but the pressure plates still looked like this after about 6 years.