Mowing Caroni 1900 flail mower help needed

[Trails End]

More info;

I ran the mower for 3 minutes at 540 rpm (no load) and got the following temps with an IR thermometer:
1) the back of the belts 165*
2) face of idler 131* but this is a shiny surface and I'm told the IR therms don't work on a shiny surface
3) inside center of idler 169*

Good idea, Hillbilly, so I did the same test after running the mower at full PTO rpm for 5 minutes.
Temperature readings were taken before engaging the PTO and then after 5 minutes with PTO off.

Back belt surface: 78 deg /120 deg
Idler inside center: 78 deg / 120 deg
Shaft housing: 74 deg / 79 deg measured half way between gearbox and pulley housing
Gearbox: 78 deg / 87 deg

All temps are in deg F

It appears that my temps were a bit lower after 5 minutes than yours after 3 minutes.
Not sure if we can make any determinations from that but it's there for whatever it's
worth.

I'll have to try temperature measurements after my next mowing.

 

[Hilbilly]

I posted some more info about my mower, in the "Lets Talk Flail Mowers" thread, since I didn't want to hijack yours. Basically what I was looking for after running the mower for only a short time, was the source of the heat. After running it for the 3 minutes I took the belt cover off and felt around to find what was hot and what was cool. I found the idler and the back of the belts were hot but not the inside of the belts. Therefore it was obvious that the idler was causing the heat. Then I need to figure out why.

Here is part of what I posted in the other thread:
I then used the mower in ambient temps of 65* for about 45 minutes and it was raining. By the time I got back to the shop, grabbed some tools, the IR therm and got the cover plate off the belts, the back of the belts were 267* and the inside center of the idler was 269*. The outboard end of the cross tube was 141*. They cool down quickly, so I imagine the temps were even higher while operating the mower.

The source of the heat is obvioulsy the idler but the bearings feel fine. So either the bearings are not OK or there is friction between the belts and the idler, meaning they are slipping. But I can't see that being the case either.


If you check that thread you will see what I went through trying to get the idler to run cooler but have not yet determined the cause of the heat or the fix.

 

[finn1]

A belt relies on friction between the sides of the belt and the shives of the drive and driven pulleys to transmit power.

A byproduct of the fiction is the generation of heat.

The same holds true for a gearset. Transmitting power generates heat at the geartooth interface.

It’s physics.

 

[Hilbilly]

A belt relies on friction between the sides of the belt and the shives of the drive and driven pulleys to transmit power.

A byproduct of the fiction is the generation of heat.

The same holds true for a gearset. Transmitting power generates heat at the geartooth interface.

It’s physics.

Of course it is but is 269* F is normal. I think not. Plus the heat on my mower is not being generated on the inside of the belts, where it rides in the sheaves, it is being created at the back of the belt where it rides on the idler. That is what I am trying to trouble shoot. If you have any ideas as to the possible cause of the excessive heat, they would be appreciated.

 

[rv7charlie]

I'm normally not a big fan of 'shotgun troubleshooting', but in your case, it sounds like you've methodically narrowed down the source of the heat to one pulley. How expensive would it be to just replace it, to see if things improve?

For a totally non-tractor reference, my low mileage 2008 BMW 3 series was intermittently squeaking from somewhere under the hood. I used the old screwdriver-as-stethoscope trick & it seemed to come from the accessory belt idler. I replaced the idler, and when I checked the old one, the bearing felt perfectly smooth, with no dragging, and it didn't spin free like it was completely dry of lubricant. But...no more squeaking from the car. Sometimes a component won't exhibit a problem until it's truly loaded down in use.

FWIW,

Charlie

edit: I assume that you've checked to be sure that the pulley is aligned properly in the belt path, right?

 

[Hilbilly]

I'm normally not a big fan of 'shotgun troubleshooting', but in your case, it sounds like you've methodically narrowed down the source of the heat to one pulley. How expensive would it be to just replace it, to see if things improve?

For a totally non-tractor reference, my low mileage 2008 BMW 3 series was intermittently squeaking from somewhere under the hood. I used the old screwdriver-as-stethoscope trick & it seemed to come from the accessory belt idler. I replaced the idler, and when I checked the old one, the bearing felt perfectly smooth, with no dragging, and it didn't spin free like it was completely dry of lubricant. But...no more squeaking from the car. Sometimes a component won't exhibit a problem until it's truly loaded down in use.

FWIW,

Charlie

edit: I assume that you've checked to be sure that the pulley is aligned properly in the belt path, right?

I've been away for a couple of weeks and haven't done any more since then. I did check out the pulley alignment previously and found it to be out slightly. I fixed that and the problem persisted. So I have decided to replace the idler bearings when I get time and will report back here afterwards, with the results. I think you are right. I can't see how anything else could be the cause, since the heat source is definitely the idler.

OP, have you fixed your problem and if so, how?

 

[Hilbilly]

Update: I pulled the idler and got the bearings out with some effort. After cleaning them out in the ultrasonic cleaner I could clearly feel that both bearings were bad. I have new ones waiting for me in the big city and will have them picked up tomorrow. I am very sure this was the problem with my mower. It's odd that I couldn't feel anything wrong with them when they were in place and all greased up but it was very obvious when they were cleaned up.

I'll let you know how it goes after I get them replaced. However I will have to wait for my tractor to be returned from the shop. It was one of the Kubotas that was recalled to be split, to check for a possible improperly torqued bolt in the transmission. It left my place yesterday evening and I won't get back to this for at least another week or 2.

 

[Trails End]

OP, have you fixed your problem and if so, how?

At this point, I'm still not sure if there is even a problem. I mowed for about an hour
yesterday, and didn't experience any problems. The area that seemed hot to the
touch after my first mowing was still hot but can't say whether it's too hot or not
at this time.

I mowed again today for about an hour, still with no apparent problems. The drive shaft
housing from the gearbox to the pulley enclosure was still hot to the touch. At this point,
I'm going to consider this normal.

By the way, I did receive and install the British Metrics extension on the oil vent and
sucess - no gear oil leakage today.

 

[BrokenTrack]

There is nothing wrong with your mower, as I have an Alamo Flail mower and it does the same thing. That is why the belts are Kevlar after all, because regular belts are just not going to cut it. If you buy autopart store belts, you end up putting them on one right after another because they cannot handle the rough service.

The gearbox on my PTO generator gets amazingly hot too.

If you are really concerned, you should affix a temperature gauge to the gearbox, and then run the mower. Right now you are just assuming it is running too hot, but what you really need to do is run it, and find out what temp it runs at, then if it gets above the normal operating temperature (which could be pretty high like on my PTO generator's gearbox), then you have a reason to be concerned.

 

[Hilbilly]

There is nothing wrong with your mower, as I have an Alamo Flail mower and it does the same thing. That is why the belts are Kevlar after all, because regular belts are just not going to cut it. If you buy autopart store belts, you end up putting them on one right after another because they cannot handle the rough service.

The gearbox on my PTO generator gets amazingly hot too.

If you are really concerned, you should affix a temperature gauge to the gearbox, and then run the mower. Right now you are just assuming it is running too hot, but what you really need to do is run it, and find out what temp it runs at, then if it gets above the normal operating temperature (which could be pretty high like on my PTO generator's gearbox), then you have a reason to be concerned.

What is the normal operating temperature range for your mower and for your PTO generator? Numbers please.

I am sure there is a range of temps that are considered normal but without the numbers there is no way to determine if your mower or mine are running at normal temps. My mower idler gets up to 270* and that temp was taken after driving the tractor back to the shop and taking the belt cover off. So I am sure the temp was much higher while the mower was being used. There was also a small puddle of liquid grease sitting in the recess of the idler pulley, which I believe was grease that got too hot. From what I found on the grease manufacturers website, that grease is suitable for temps up to 300*. So I am pretty sure my mower is running too hot. I will know better when I get my tractor back and can run it with the new bearings.