Equipment Haulers

Still nothing from Michigan Cat, beginning to think I just got blown off

 

I have a friend who works for CAT. Maybe I can see if he can ask an engineer. He works at a ship/locomotive engine plant though so I'm not to sure if they'll know as much about the equipment side of it.

 

Still no reply either.

 

The only info I could find on this matter it.

It was part of the info used for a patent on an exhaust sock.
http://www.patentstorm.us/patents/6736237/description.html

Would still like to here what CAT or another manufacturer has to say about it.

Heavy machinery, namely construction vehicles, for instance, loaders, diggers, bull dozers, etc., are usually delivered to a construction or work site piggybacked on either a flat bed of a tractor trailer combination or a flatbed railroad car. Modern heavy machinery construction type vehicles are driven by turbo charged diesel powered engines. Turbochargers compress the air flowing to the engine letting the engine squeeze more air into the cylinders, and thus more fuel can be added obtaining a greater explosion in each cylinder. A turbocharged engine produces more power overall than the same engine without turbocharging, which can significantly improve the power-to-weight ratio for the engine

The turbocharger uses the exhaust flow from the engine to spin a turbine, which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 rotations per minute (rpm) and because it communicates directly with the exhaust, the temperatures in the turbine are also very high. The turbine and pump utilize bearings which of course allows them to spin, and these bearings thus must be substantially continuously supplied with lubricant during operation of the vehicle.

In order to handle speeds of up to 150,000 rpm, the turbine shaft has to be supported very carefully. Most bearings would explode at speeds like this, so most turbochargers use a fluid bearing. This type of bearing supports the shaft on a thin layer of oil that is constantly pumped around the shaft. This serves two purposes: It cools the shaft and some of the other turbocharger parts, and it allows the shaft to spin without much friction.

While being transported to and from construction sites by a separate vehicle, the heavy construction vehicle is inoperative, i.e. the engines in most cases being completely shut down. During such transportation, the machinery is subjected to air flow passing around the exhaust stack which generally extends up above the vehicle. This external air flow can create a vacuum down through the exhaust stack, and into the turbocharger, which as discussed above, is connected with the exhaust. When such a vacuum develops through the exhaust and turbocharger the turbine and pump may be caused to spin. As is apparent to those of skill in the art, without the engine operating no oil or lubricant is supplied to the turbine and pump and thus significant wear and failure of the turbocharger may result. It is therefore well known in the art of the necessity to cover the opening of the exhaust stack to eliminate any vacuum or air flow created by the transportation of the heavy machinery while the engine is shut down.


Read another article for Cummins turbo engines, that said the cover was to prevent dirt, debris, and water from entering the engine.

 

Thanks for this info. Now, why don't they seal the air cleaners and stop the air from being forced in to the turbo???????????????????????

 

Can't say for sure, not very much info out there in cyberspace on this one. took about 20 minutes of digging to find that little bit.

If its the second bit about dirt, dust, etc. Then only the exhaust would need to be covered as the air cleaner would protect the other end.

 

So, it looks like the turbo would be spinning the normal direction with the air being sucked through, and not blown into the engine. Still, no oil,,,,,,,,,,fried turbo bearings.

 

I haul 1 or 2 john deere loads a week out of Dubuque and Davenport ....psl ( yard contractor) nor JD care about covering the exhaust. The broker and the owner I work for require it.

 

Case and Agco both spec sealed exhaust on some models and you have to sign that it is sealed before leaving. Didn't understand it but complied.