Electric conversion of a Kubota B26 / Similar

[galstaf]

Would be interesting project to figure out.

Get a shop manual to get answers to your many questions adapting to many of systems like electrical, hydraulic, cooling, etc. Mining equipment generally is built for the dirty environment TLBs live in.
Not going to easy, cheap or as safe as OEM. Good luck.

I have a shop manual of course. I realize it is not a simple project but was looking for leads on anyone that had done something similar that I could potentially collaborate with.

 

[sea2summit]

I already have a similar diesel tractor. I was looking at this to be able to use tractor in an enclosed space without fumes and also be able to use it quietly in residential areas.

I was really looking for someone that had already done this on a similar SCUT. I saw a converted power trac and figured someone in the world must have converted a kubota tractor by now.

I wouldn't be surprised to learn someone has done a SCUT but I'd be very surprised to hear they spent money on a fairly new Kubota for the project.

 

[galstaf]

Yes, I'd like to know what is wrong with that diesel too. Fixing that would be the path of least resistance.

For electric, you would need a constantly running motor for the hydraulics and a different motor for the transmission and PTO. Even then, you wouldn't have a live PTO. I would not use any of the existing diesel and build custom gearboxes to match motor to load.

Honestly I have not used the PTO ever. Only ever used the Backhoe and loader. The motor and motor controller would be matched to the load requirements as much as possible.
I was really looking for leads on anyone that has actually done this or something similar.
I have followed a number of forums on replacing diesels in other environs such as marine.
My application rarely needs the tractor to run all day, so I figured it may be a good fit.

 

[galstaf]

I wouldn't be surprised to learn someone has done a SCUT but I'd be very surprised to hear they spent money on a fairly new Kubota for the project.

There will be a massive push into electric everything in the next decade or so. I am hoping to see conversion kits similar to what are available to convert automotive applications.
Depending on how the tractor is used, I think it would be a good fit for a number of applications; especially in construction situations where the machine spends a lot of time sitting and waiting and a loud agricultural diesel engine is less than desirable.

 

[MossRoad]

I was just offered a great deal on a Kubota B26 with a blown engine. Hydraulics apparently work just fine.
I am really interested in converting it to use a bunch of lithium battery packs from eBikes I got at an auction. There are 36V and 48V packs (42V to 54V when fully charged). Decent capacity.. 500Wh to 1kWh each.

Has anyone attempted this? I am thinking to remove the engine and find a similar spec 3 phase electric motor up 20 kw. I know electric motors are more torquey that ICE, so that may be overkill?

Thinking to run the motor at 72-96V on ebike batteries in series.

Remove engine but keep the flywheel mechanism and maybe some of the crank shaft to drive a pulley with the electric motor? The flywheel already connects to the electric starter motor so would that be strong enough to handle a 20kw motor via gear drive??

The attached pics show starter motor that drives flywheel.. but that may only handle the HST drive and the PTO.

There is a hydraulic pump on the RHS of the engine with a pump for the loader and backhoe and another for the steering mechanism. Any suggestions on how to handle that?

If anyone has anything that is remotely relevant, please post as much detail as you can. I am sure that there are many more people interested as the price of the tech comes down. What sort of motor / controller / etc etc did you use and how is it working out?

To break it down:
- you need something to spin the transmission for motion (new electric motor).
- you need something to spin the hydraulic pump (looks like 2 section pump) for FEL/backhoe and steering.

I'd mount the new electric motor to the transmission stub with any necessary gearing (if any) and put a gear on that shaft to drive a chain to drive the hydraulic pump off to the side.

The motor will have to run continuously to provide power to the FEL/backhoe and steering, and will only be tasked with running the transmission when it's moving.

However, by using only one electric motor, you'll have some parasitic battery drain because of spinning the transmission even when it's in neutral. So maybe a separate electric motor for the hydraulic pump(s) would be better.

You won't need that complicated of a drive for the electric drive motor. Maybe steal something off of an electric forklift salvage.

Interesting project. Many considerations. Good luck.

 

[MossRoad]

And by electric forklift salvage, I'm not talking about converting the drive pedals on the tractor. Leave those as they are.

I'm talking about a series of switches to select low/medium/high speed on the electric motor instead of the forklift drive pedals.

Hope that clears that up.

Again, good luck on your thought process.

 

[unimog_jason]

Not directly related, but you might want to check out Jerry Rig Everything on YouTube, https://www.youtube.com/channel/UCWFKCr40YwOZQx8FHU_ZqqQ

He's doing an electric conversion on a retired HMMWV that might give you some ideas on the some of the problems you'll need to overcome.

 

[ptsg]

I like Moss's approach on this project, very similar to what I would do. A single electric motor for everything, to keep simple and functional. Leaves more space for more batteries as you don't have to run a separate motor and controller for the pumps.

It will probably need some sort of subframe build to attach the rear half of the tractor to the front axle frame.

Some sort of speed adjustment, either 2 or 3 speeds. Almost like an ECO mode.

 

[IndyJay]

I like Moss's approach on this project, very similar to what I would do. A single electric motor for everything, to keep simple and functional. Leaves more space for more batteries as you don't have to run a separate motor and controller for the pumps.

It will probably need some sort of subframe build to attach the rear half of the tractor to the front axle frame.

Some sort of speed adjustment, either 2 or 3 speeds. Almost like an ECO mode.

Maybe a L/LL pressure switch on hydraulics to control pump speed, depending on load/activity.

 

[galstaf]

To break it down:
- you need something to spin the transmission for motion (new electric motor).
- you need something to spin the hydraulic pump (looks like 2 section pump) for FEL/backhoe and steering.

I'd mount the new electric motor to the transmission stub with any necessary gearing (if any) and put a gear on that shaft to drive a chain to drive the hydraulic pump off to the side.

The motor will have to run continuously to provide power to the FEL/backhoe and steering, and will only be tasked with running the transmission when it's moving.

However, by using only one electric motor, you'll have some parasitic battery drain because of spinning the transmission even when it's in neutral. So maybe a separate electric motor for the hydraulic pump(s) would be better.

You won't need that complicated of a drive for the electric drive motor. Maybe steal something off of an electric forklift salvage.

Interesting project. Many considerations. Good luck.

Yeah... that's kinda what I was thinking, probably a two motor setup. The hydraulic pump(s) for the B26 don't really look like much of anything. I am not sure exactly what it would take to replace it with electric at this point; but open to suggestions!

I was thinking also of a hydraulic reservoir to store up a bit of pressure to drive things for a couple of seconds while the hydraulic motor comes up to speed so the hydraulics motor doesn't have to run continuously at full whack once it comes up to operating temperature.
I was also thinking that a good compromise might be to run at high speed to move the FEL etc, then have it drop down to "maintenance speed" once the hydraulic controls are released. Just keep the system pressurized enough so that the hydraulics don't sag as if the tractor was turned off.

As for the motors, definitely thinking something off the shelf industrial with appropriate motor controls.
It's a lot, but the thought of a whisper quiet tractor intrigues me!