fan belt fail M7060HDC

   / fan belt fail M7060HDC #1  

RoyKing

Platinum Member
Joined
Nov 4, 2017
Messages
840
Location
Gainesville Florida
Tractor
M7060HSC/18, RTV-X1100C
Runs AC & Waterpump less than 100 hours, anybody else have trouble with AC belt slip
 

Attachments

  • FanBelt.jpg
    FanBelt.jpg
    104.9 KB · Views: 155
   / fan belt fail M7060HDC #2  
No but I'm guessing not tight enough from the factory... and never rechecked.....:confused3: But buy a good belt made in the USA, Gates or NAPA....
 
   / fan belt fail M7060HDC #3  
Yep, check the tension.

I wish the newer machines had automatic tensioners.
 
   / fan belt fail M7060HDC
  • Thread Starter
#4  
I think Kubota goofed that belt doesn't wrap far enough around the AC pump pulley, to get enough grip. They should use a flat idler and gone under the tension pulley
 

Attachments

  • ACBELT.jpg
    ACBELT.jpg
    265.8 KB · Views: 297
   / fan belt fail M7060HDC #5  
To my eye that belt looks like one that has been run at the limit of it's ability to handle heat and stress. Do you tend to run your 7060 at high RPM & the AC turned up?

There's a lot that goes into the V-belt versus flat belt versus tooth belt debate. The other day I was reading a technical paper about belt and pulley design. This one wasn't about wear or lifespan so much as being about the sound that a belt makes as it constantly traps, compresses, and then releases air. I'm always surprised at how little I know....

It turns out that flat belts and toothed belts have a bit more of a problem with making noise from air compression than V belts do. V belts can leave a space at the bottom of the "V" on the pulley for an air passage. Apparently that helps..... I had never thought much about it.

As with a lot of things that wear, the real solution to wear and noise on belts is simple and the same as wear & noise generally - just design whatever you are drawing up to be a bit larger and run it slower. There's a theoretical efficiency advantage in smaller&faster that doesn't translate well to the real world where things are often more efficient larger&slower. The downside is that designing components - like say an AC compressor - to be a tad larger and run a tad slower tends to cost more on the manufacturing side.
enjoy,
rScotty
 
   / fan belt fail M7060HDC
  • Thread Starter
#6  
hopefully because nobody else has mentioned it was fluke, that a new belt and proper tension will cure. Was very hot and turning a bush hog doing heavy cutting at 600 pto speed. I thought general rule was cover at least 90 degrees with belt the AC looks to be only slightly over 45 degrees
 
   / fan belt fail M7060HDC #7  
Looks like the more you tension the belt - the less coverage you get on the air compressor pump pulley. Perhaps - not the best of designs.
 
   / fan belt fail M7060HDC #8  
I think Kubota goofed that belt doesn't wrap far enough around the AC pump pulley, to get enough grip. They should use a flat idler and gone under the tension pulley

I bet if you looked around you could find a flat pulley maybe smaller diameter and put the belt under the tension pulley......
 
   / fan belt fail M7060HDC #9  
I bet if you looked around you could find a flat pulley maybe smaller diameter and put the belt under the tension pulley......

ditto I never noticed until now that my M7040 has same type location of belt tensioner.. My tractor has over 1600 hrs on original belt. I do think AC sheave should have more pulley to belt contact area.
 
   / fan belt fail M7060HDC
  • Thread Starter
#10  
Will a vbelt work with smooth pulley running on its backside as a tensioner like the wide flat serpentine belts do? I could find idler then spacer out and adjust belt length.

In the mean two new belts are on the way and closer attention will be paid to that belt, leave the guard off for awhile
 
 
Top