do low rpm s hurt the hst tractor
cthonestguy
Join Date: Jun 2004 Posts: 267 northeast |
2004-10-02 97554
Anyone know for sure if the myth that running a hydr at low engine speed (RPM) will damage the pump in the long run? I was always under the assumption that you should always keep the RPMs up or if you lug it you will overheat the pump. I have a bx2200 and usually run it close to 3/4 or open when working hard. Can anyone put this myth to bed for me once and for all? Jim
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
cherymax
Join Date: Mar 2004 Posts: 80 Grantville, GA Pics |
2004-10-02 97557
If this myth had any merit, your owners manual would contain a big "Hydorstatic transmission damge may occur..." warning. ....
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
hardwood
Join Date: Dec 2002 Posts: 3583 iowa |
2004-10-03 97561
At 3/4 throttle the pump is spining fast enough to be fine. If you were just above low idle I'd worry more about stress on the engine than the pump, at real low rpm the engine doesn't produce enough torque to hurt the hydro. Frank. ....
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley |
2004-10-03 97566
I haven't heard anybody say that they knew of a pump damaged by over-heating due to low rpm's or read of it either. That in itself certainly doesn't constitute a final word however.
I think it is more of a theoretical than practical issue. Few persons would to operate a tractor in a way that might make the theory a possibility. In my mind the theory has to do with heat dissipation, and some systems may depend more on circulation to dissipate heat than others. Work done at low rpm does require more torque than at higher rpm's. In extreme low rpm/high load situation it may be possible for a system to generate heat faster than it dissipates. ....
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York Pics |
2004-10-03 97602
At low Rpm's when the hydro is stressed it could cavitate in the pump and dry the hydro causing damage. ....
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley |
2004-10-04 97614
Art added another possibility and likely a more realistic one than mine. In this context, I imagine that a stressed HST means slow idle rpm and max speed pedal.
I can see cavitation happening under such conditions and I suppose there's a limit to the range of operation that engineering can provide for. Cavitation itself generates heat so maybe that's the origin of these myths, so possibly they aren't really myths. Still, few people would do serious work with any tractor at slow idle rpm's nor should they. ....
Reply to | Quote Reply | Add Photo
do low rpm s hurt the hst tractor
beagle
Join Date: Jan 2004 Posts: 1333 Michigan Pics |
2004-10-04 97651
It would seem best to run the engine at at least 2/3 rated rpm whenever you are operating. At this rpm, you are running the engine at it's highest torque rating and in it's most efficient operating range. Running at low rpms not only makes heat dissipation difficult for the transmission, but also for the engine. ....
Reply to | Quote Reply | Add Photo
Go Top
Share This