Converting Belt Drive Trans to Hydraulic Motor

[J_J]

You can make things work using hyd, but you are limited with the HP.

I believe the engine will run at 3600 rpm.

http://www.brandnewengines.com/422707-1705.aspx

 

[allyolds68]

You can make things work using hyd, but you are limited with the HP.

Is that due to losses due to the use of the hydraulics? I would think the belt drive might be slightly more efficient but I wouldn't think it would be so much more efficient that you couldn't run hydraulics instead. I would hope Struck would have sized these engine to run drive systems and auxiliary hydraulics together but the reality is other than lifting the front bucket while crawling you usually don't use both these systems at the same time. I'm obviously a newbie with hydraulics but I'm an engineer that's worked in heavy construction for 25 years so I'm willing to learn. If the engine works (which I am still not sure of based on your responses) I guess the next step is to size the system and price it. I assume I need a belt driven hydraulic pump which, in turn, runs a hydraulic motor (controlled by a valve). The hydraulic motor doesn't necessarily need to spin at 3600 RPM as long as it has the torque because I can vary the pulley size, correct?

Is there a decent website to use to size the system?

 

[J_J]

Some hyd motors loose about 15 % efficiency loss

The first Struck Magnatracks used belt and pulleys for the speed and torque.

My M1800 and your M3000 used a Peerless transmission to acheive the speed and torque.

The newer models of Magnatrack, use hyd to power the drive system and all implements.

I would think you would need a larger engine, say a 25 HP to run the hyd required to drive the machine and power the implements.

Do you want to drive the transmission with a hyd motor, or replace the transmission with a hyd motor.

or

Do you want to replace the Peerless transmission with a small tractor hyd transmission? If so, you will have to match up engine to transmission and take the weight of the M3000 into account.

I suggested each track be driven by a hyd motor, for independent action. but there are many ways to get the job done.

I also have a Power-Trac which is a 4 wheel drive, articulating steering. Each wheel is driven with a hyd moto, direct coupled.

My engine is a 45 HP, and drives the variable speed hyd pump, and a PTO pump and a steering/loader pump.

My idea for my hyd convrsion would be to remove the Peerless transmission and attach a hyd motor to each side, and select a pump to drive the hyd motors using a hyd motor spool valve.

The speed of the hyd motor is determined by the displacement of the motor and the RPM

 

[allyolds68]

Some hyd motors loose about 15 % efficiency loss

The first Struck Magnatracks used belt and pulleys for the speed and torque.

My M1800 and your M3000 used a Peerless transmission to acheive the speed and torque.

The newer models of Magnatrack, use hyd to power the drive system and all implements.

I would think you would need a larger engine, say a 25 HP to run the hyd required to drive the machine and power the implements.

Do you want to drive the transmission with a hyd motor, or replace the transmission with a hyd motor.

or

Do you want to replace the Peerless transmission with a small tractor hyd transmission? If so, you will have to match up engine to transmission and take the weight of the M3000 into account.

I suggested each track be driven by a hyd motor, for independent action. but there are many ways to get the job done.

I also have a Power-Trac which is a 4 wheel drive, articulating steering. Each wheel is driven with a hyd moto, direct coupled.

My engine is a 45 HP, and drives the variable speed hyd pump, and a PTO pump and a steering/loader pump.

My idea for my hyd convrsion would be to remove the Peerless transmission and attach a hyd motor to each side, and select a pump to drive the hyd motors using a hyd motor spool valve.

The speed of the hyd motor is determined by the displacement of the motor and the RPM

I understand that a switch to a total hydraulic drive system is the best way to make the machine better but it involves more time and money than I have. I don't like the belt drive and clutch system and I was thinking I could improve on it by leaving the Peerless transmission but making it driven by a hydraulic motor so I eliminate the clumsy belt/clutch system. A further thought was that perhaps I could use a control valve (and motor) that reversed flow so I could run the machine in forward and reverse without having to shift the Peerless trans except from low to high. I have NO IDEA if a Peerless transmission can even be run backwards but that isn't really a neccessity as long as the transmission can be shifted. I also like the idea of the hydraulic pump being able to be used for other applications like a PTO.

 

[allyolds68]

I just got off the phone with Warren at Struck. He said he wouldn't see a real benefit to doing what I'm proposing. He told me that the transmission is the weak link and driving it hydraulically could damage it. He said the engine is matched to the trans to cause the engine to stall before damage is done to the trans. I didn't realize that there are four forward speeds but 1st and 2nd are locked out (I thought they were a three speed with 2nd locked out) They're locked out because the motor could damage the transmission if you load the engine in a lower gear. It was an interesting conversation. He really knows the machines.

 

[J_J]

Your 18 HP engine can support a 8.7 GPM pump @ a pressure of 3000 psi.

So if you run the 8.7 GPM through a 10 cu in hyd motor, it will turn at 201 rpm, and the torque will be about 3,777 in lbs.

If you want a faster speed on the hyd motor, then you select a smaller cu in motor, say 3 cu in, and the speed will be 670 rpm, and the torque will decrease to 1,433 in lbs.

In order to get lots of torque from a hyd motor, you need large cu in displacement motors, and the GPM's to turn it at some speed.

The GPM from the hyd pump will be determined by the size of the pump in cu in, and the rpm, but say you need 20 GPM, and the engine will turn the 1.3 cu in pump at 3600 rpm, then the engine that can produce the 20 GPM GPM will have to be at least 41 HP.

Right now, your torque is acheived by the Pearless transmission, which is more efficient that a hyd system.

As far as the belt keeps turning when the clutch is depressed, maybe there is not enough slack , or the belt is stretched, or wrong belt.

Maybe you don't have a Peerless transmission, as I can use all the gears on my M1800. In low gear, you can get off the machine and eat lunch and when you return, it hasn't moved very much.

When I first received the machine, I thought I knew how to operate the levers, but not so, I did not realize that the levers are brakes. Pull the right lever and the machine turns to the right, etc. I had to get it off a trailer, in the rain, I was cussing something awful.

 

[allyolds68]

Thanks for all the hydraulic info. I still haven't totally dropped the idea. Warren explained to me that if the clutch is adjusted correctly it will physically stop the belt from moving, not just take the tension out of it. I understand that because before I pulled the transaxle out I adjusted the clutch and had it working correctly. The MT3000 is definitely a 4 speed with an insert which locks out 1st and 2nd. It's a Peerless 2338B transaxle. I know how the levers work. When you pull a lever it put the brakes on the side you are pulling, stopping or slowing it. The transaxle then sends twice the axle speed to the other side. I've run a fair number of dozers (not very well I might add) so I'm pretty familiar with them.

I think a big part of the problem I have is I haven't used it enough to get used to it. After I got it running I was having a problem with something binding in the drivetrain. It turns out the main drive chains were rusted up badly. Warren told me that problem alone could cause me the issues I was having. I would have continued running it the way it was and just fixed the chains except the input shaft seal was leaking pretty badly. I pulled out the whole transaxle and had the seal replaced. One gear ended up needing to be replaced as well. That whole adventure is another story..... I'll never take anything to be fixed again. $385 to replace a seal.... I knew I should have done it myself.

 

[J_J]

Surplus Center

http://www.surpluscenter.com/item.asp?item=13-1489&catname=powerTrans

 

[allyolds68]

Surplus Center - ZTR LH/RH HYDRO-GEAR ZT-220O EZT TRANSAXLE ASSY

Wow. I hope I can get those to fit my 52" Ferris Walk Behind when the time comes to replace the drive motors. The hydraulic transaxles Ferris uses (I think they're Peerless) run $1500..... A SIDE!

But back to your point, yes, I would hope those would make good drive motors for the MT3000. My Ferris has got a 17 HP Kawasaki but doesn't need the torque that a Struck would need. I'm not sure if you could reduce the gears enough to get those motors to work. Then again my mower has a tire that's probably 12" in diameter. The drive gear diameter on the Struck is only about 3"

 

[aczlan]

Wow. I hope I can get those to fit my 52" Ferris Walk Behind when the time comes to replace the drive motors. The hydraulic transaxles Ferris uses (I think they're Peerless) run $1500..... A SIDE!
But back to your point, yes, I would hope those would make good drive motors for the MT3000. My Ferris has got a 17 HP Kawasaki but doesn't need the torque that a Struck would need. I'm not sure if you could reduce the gears enough to get those motors to work. Then again my mower has a tire that's probably 12" in diameter. The drive gear diameter on the Struck is only about 3"

150 RPM on your 3" drive sprocket would be ~16MPH at 150RPM with 115FT/# of torque (assuming that that is the sprocket that actually turns the track). Any idea how fast it turns now?
If you went to a 3:1 reduction (ie: 3" drive sprocket and 9" driven sprocket or a 3" drive sprocket to a 6" sprocket on a jackshaft which had a 3" drive sprocket to a 4" driven sprocket on the track drive sprocket), you would drop the speed to ~56RPM or ~6MPH, but would up your torque to ~306FT/#.

Aaron Z