CK20HST hydrostatic drive operating RPM's

lcisled · Oct 8, 2004

CK20HST hydrostatic drive operating RPM\'s

I have a CK20HST. My friend is in the construction industry and was at my shop looking at my tractor. He said to always have the tractor at maximum RPM while operating the machine. He said that hydrostatic drives operate more efficiently at max RPMs and if less than that, it creates unnecessary wear and stress on the drive. He learned this through his time operating BH and excavators in the construction industry. I use mine to spray my lawn and to get a constant speed of 3 MPH I have to run it at about 2000 RPM with the pedal fully down. With a hydrostatic drive, there is no way to get the exact same speed on the pedal with the tractor at max RPM. I have to believe that Kioti knows we are going to operate the tractor without it being at max RPMs. I have thought about it a lot since then, and it makes sense. It pulls harder on the drive with less oil being pumped through it and also not running as efficiently as at full oil flow. Are we creating undue stress and wear on the drive by doing that? I am interested in what TBNer's think.

KiotiJohn · Oct 9, 2004

Re: CK20HST hydrostatic drive operating RPM\'s

I have to believe that operating at between 2000 and 2200 for non PTO operations is not a problem. That gives plenty of flow for the pump, and in my opinion, does no harm.
Operating at PTO speeds is just not necessary. John

DK35vince · Oct 10, 2004

Re: CK20HST hydrostatic drive operating RPM\'s

( I have to believe that operating at between 2000 and 2200 for non PTO operations is not a problem. That gives plenty of flow for the pump, and in my opinion, does no harm.
Operating at PTO speeds is just not necessary. John )

I have to agree with John. Your not hurting anything running at 2000 RPM.

lcisled · Oct 10, 2004

Re: CK20HST hydrostatic drive operating RPM\'s

Thanks for the replies. I understand that there is probably not much more stress on the drive at 2000 RPM than max RPM, especially if under no load. I might be splitting hairs here, but every time that a hdro trasmission is run at a lower RPM than max, does that create more stress and wear? What if it had to be run at 1300 RPM? Is my buddy right that running a hydro at less than max at any task creating more wear on the transmission and shortening the drive life?

Bird · Oct 10, 2004

Re: CK20HST hydrostatic drive operating RPM\'s

( Is my buddy right that running a hydro at less than max at any task creating more wear on the transmission and shortening the drive life? )

I'm certainly no expert, but I'm convinced he was mistaken. If he were right, I think there'd be something in the tractors' operator's manuals telling you so, and I know, at least in my Kubota manual, mention was made of running it at 1800 to 2000 for FEL work.

KiotiJohn · Oct 10, 2004

Re: CK20HST hydrostatic drive operating RPM\'s

( What if it had to be run at 1300 RPM? Is my buddy right that running a hydro at less than max at any task creating more wear on the transmission and shortening the drive life? )
1300 RPM may cause more stress, and you would notice that the tractor was laboring at this speed.
However, I don't believe any extra wear is created by running under max rated speed. Running way low is a strain on everything, but even 1800 is not way low.
My owner's manual specifically states, "Do not run the engine at speeds faster than necessary." That's what should be done. Unless you're using a PTO implement that requires rated speed, run it at what you need to get the job done. John