pto problem

[freelancer]

why does the same wide angle pto, which a use on a forage wagon with 180hp for 10 years without problems, is getting hot on a slurry mixer with 100hp after 10 min? the 5m long mixer is mounted in 2m deep slurry pit with ca. 30° angle

 

[Mur Huwcun]

1000 rpm on wagon, 540 on the mixer? If so half the speed, around twice the torque

 

[freelancer]

more then 600 rpm is not possible with 100 HP. And 600 ist optimum speed for mixing. The mixer is ready for 1000 rpm and 150 hp

 

[Mur Huwcun]

Yes but is the wagon on a 1000rpm gearbox? The mixer whisk will be designed for 540

 

[freelancer]

No, both are designed for 1000! that cant be the problem....

 

[Exfarmer]

more then 600 rpm is not possible with 100 HP. And 600 ist optimum speed for mixing. The mixer is ready for 1000 rpm and 150 hp

Total lack of understanding here. Power is transmitted more efficiently at higher revs. 1000 rev pto’s were developed when most tractors were under 50hp and the shafts were not capable of transmitting higher torques.
Multiplying the speed up to 1000 halved the torque.
DB tractors of down to 30hp offered 1,000 rpm Pto’s but mainly to offer the option of an economy 540.
The real problem I suspect in this situation is that the PTO is running constantly at an angle which none like

 

[freelancer]

"Multiplying the speed up to 1000 halved the torque." - i know... But when i take stronger tractor on the mixer and run it with 900-1000 rpm, often the mixer is getting not enough slurry and starts to vibrate.... my question is more about the pto. i have seen, the is a 80° and 50° wide angle pto availble. Whats the difference?

 

[Exfarmer]

"Multiplying the speed up to 1000 halved the torque." - i know... But when i take stronger tractor on the mixer and run it with 900-1000 rpm, often the mixer is getting not enough slurry and starts to vibrate.... my question is more about the pto. i have seen, the is a 80° and 50° wide angle pto availble. Whats the difference?

A pto can and is indeed is designed to run out of a straight line . However when it is turning outside the straight line the joint itself slows down and speeds up on every revolution in which time energy is expended. This energy is expressed as heat. The greater the angle the greater the heat.
The design working angle is a max working angle.
Always run the mixer full if it runs short then cavitation occurs which is extremely stressful to the machine

 

[ollie989898]

As above. If you bend a PTO shaft (on the joints, obviously) out of true, the input speed isn't precisely the same as the output speed the other side. The wasted energy is heat/vibration and other grief.