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Electric tractor motors

Posted: Jul 26 2021 9:10pm
by pengyou
I have some property in the high plains desert. I would really benefit from having a motorized 4 wheel platform that would let me carry up to 4,000 pounds (500 gallons of water). It does not need to go more than 5 mph, and does not need to climb more than 20 degrees. Tires will be about 24" in diameter. It would be ideal to have 4 hub motors powering this (to eliminate drive trains), but I don't know if their is such a motor that will handle this much weight. I don't want to do gas or diesel because this will constantly be doing stop and start action, which is really inefficient for either a gas or diesel engine - move it one place, do some work for 20 minutes, then move to another place, do some work for 5 minutes, etc. Distance traveled in one day is probably <2 miles. I would be willing to consider hydraulic motors in the wheels with an electric motor to power the pump. I plan on using skid steering.

I am looking for options now for the right kind of electric motors to use for this purpose. Most of the motors I know about are used to power bikes and scooters, higher rpms than I would need.

Re: Electric tractor motors

Posted: Jul 26 2021 9:41pm
by Hillhater
You will not find a direct drive hub motor to give you sufficient torque at low speed to haul 2+ tons up a 20 deg slope.
Simplest solution if you really insist to avoid diesel , is to convert an existing small tractor to an electric motor through the existing drive train. ..its not uncommon.!

Re: Electric tractor motors

Posted: Jul 27 2021 4:46am
by stan.distortion
+1 on the tractor suggestion, you'd need reduction gearing and it would work out far more complicated to build a vehicle from scratch than modify an existing one. Skid steer would be a killer with a 2 ton load as well, you'd probably use more energy on a single 90 deg turn than in 2 miles of straight and level travelling.

And I want to see more tractor conversions! :) On paper it's a match made in heaven, heavy battery weight is a hindrance for personal transport applications but for tractors it's a bonus and electric adds a whole new area to their versatility (along with PTO's and hydraulic takeoffs) that will probably open the door to countless new implements and applications.

The torque curve is absolutely perfect too, miles ahead of internal combustion with countless gears and slick ways of changing between them. Most manufacturers are already going down that route but their offerings are usually damn great behemoths that would have barely fit in a field a century ago, let alone get through the gate! Big agri has already run the numbers and come up with a big fat plus and that's all manufacturers seem to be interested in, they don't seem one bit interested in the smaller (and usually ancient) tractors most farms have that clock up far more hours per year doing the day to day jobs.

Re: Electric tractor motors

Posted: Jul 27 2021 6:40am
by Hillhater
Small Electric tractors are available..
https://solectrac.com/eutility-electric-tractor

Re: Electric tractor motors

Posted: Jul 27 2021 10:49am
by speedmd

Re: Electric tractor motors

Posted: Jul 27 2021 12:10pm
by stan.distortion
Thanks, hadn't come across anything like either of those before. Didn't think the second really qualified but it's hiding a damn sturdy structure and running gear under its golf buggy exterior, add a 3 point linkage and heavily treaded tyres and it could work well as an agricultural workhorse.

Re: Electric tractor motors

Posted: Jul 27 2021 5:51pm
by speedmd
More traditional looking orchard size hybrid tractor.
https://www.alibaba.com/product-detail/ ... bb8fwrJIA4

Several mini loaders are coming up with a search for "articulated", which may be a good option for quick steering. 500 gallons, I would consider putting on a tank trailer.

Re: Electric tractor motors

Posted: Jul 27 2021 6:40pm
by Jordan325ic
speedmd wrote:
Jul 27 2021 5:51pm
More traditional looking orchard size e tractor.
https://www.alibaba.com/product-detail/ ... bb8fwrJIA4

Several mini loaders are coming up with a search for "articulated", which may be a good option for quick steering. 500 gallons, I would consider putting on a tank trailer.
Did you send the wrong link? That's clearly a "4 stork" diesel motor in that one... "electric" refers to the electric starter.

Re: Electric tractor motors

Posted: Jul 28 2021 7:09am
by speedmd
Wrong link. Too many open at same time. :oops: Ali suppliers are always showing one thing and selling something very different. Careful with them. Looks like it may have electric drive on the hydro side on some models. Nice looking orchard tractors if they are not just stock photos.

Wanted to show the articulated mini loader. https://www.alibaba.com/product-detail/ ... swMqgw&s=p

The rickshaw-small side by side and golf cart type axles are made in a bunch of sizes and with high reduction ratios by a bunch of folks. Something like these would pull a tanker or be adapted. https://www.alibaba.com/product-detail/ ... 57b77JAPRn

Re: Electric tractor motors

Posted: Jul 28 2021 7:33am
by spinningmagnets
The heavy load and slow wheel-speed call for a high reduction. Cylindrical motors such as the QS 138/70H would be easier to package and mount under the cargo bed, but it is "possible" to use a hubmotor for a chain-drive to an axle, though i do not recommend that.

I appreciate the simplicity of hubmotors, and they have their place.

I would look for a large 4WD quad ATV with a fried engine to acquire the parts for the undercarriage.

I would use one motor for the rear axles, and a second motor for the front axle. Best of luck with whatever you choose, and please post pics of the results.

Re: Electric tractor motors

Posted: Jul 28 2021 8:04am
by stan.distortion
It would probably need an awful lot more weight than quad running gear could handle, either towing or carrying about 2 tons. A smallish tractor would be the ideal imo but usually the engine block is part of the structure/chassis, shouldn't be too hard to fill in the gap but it would need to be a damn heavy structure. A site dumper could be a good alternative, usually the engine and gearbox are on simple mountings with a driveshaft for the transfer box, easy to adapt to and high reduction. They usually need to be fairly well loaded to have enough grip for towing (could be a good candidate for lead-acid), articulated steering kicks ass for reversing trailers!

EDIT: Hydraulic steering (and tip if kept), could be more work getting that working than the drivetrain :/ An electric forklift or truck tail lift pump/motor with a torque sensing switch on the steering column could be a cost effective option. Voltages might not work out well though, a qs138/70 would be plenty capable for the weight with the low speeds specified but 48v would limit it a lot and 24v would likely be far too low.

Re: Electric tractor motors

Posted: Jul 28 2021 1:57pm
by speedmd
My Polaris electric ranger in 4wd low has no traction or power issues pulling around a 5 x 10 trailer fully loaded with hardwood up a 5% grade. Depending on the wood - moisture it's easily the weight we are talking about. I would not even attempt it in the economy power setting or out of 4wd. On board, anything much larger than 100- 120 gallons would not be a good fit for it's structure. The diesel compact tractor in low range does not even feel the full trailer. :) The loaded rear tires alone weigh close to the weight of the polaris with the wet batteries. Expect the ranger will not have its current traction once the battery gets swapped out to the Li pack which should shed some 750 - 800 pounds.

Re: Electric tractor motors

Posted: Jul 28 2021 2:23pm
by fechter
The tractor needs to weigh more than the load to get traction. Ideally you want your water tank on the tractor.

They sell incredibly inexpensive tractors in China:
https://www.alibaba.com/product-detail/ ... 97303.html

Here in the states, I'd be looking for a gas one with a blown engine and do a conversion.

Re: Electric tractor motors

Posted: Jul 28 2021 2:48pm
by spinningmagnets
If the cargo is two tons (4,000 lb), then I suspect the loaded vehicle will have no problems with traction.

4K lbs is the weight of a full sized pickup truck with a V8. Thats heavy, certainly, but...

You are gearing it to 5 MPH with 24-inch tires. Full-sized commercial aircraft are maneuvered at the service hangar by a tractor that has a surprisingly small engine, because it has a low gear around 5-MPH.

I don't know what the cheapest ideal system is, but I would never consider a hubmotor for this.

Re: Electric tractor motors

Posted: Jul 28 2021 8:56pm
by Hillhater
spinningmagnets wrote:
Jul 28 2021 2:48pm
I don't know what the cheapest ideal system is, but I would never consider a hubmotor for this.
Well how about 2 hub motors then ?..

But this is a more conventional , low cost, electric conversion of a traditional tractor...


Youtube has loads of similar low cost conversions.

Re: Electric tractor motors

Posted: Jul 28 2021 9:14pm
by Hillhater
fechter wrote:
Jul 28 2021 2:23pm
The tractor needs to weigh more than the load to get traction. Ideally you want your water tank on the tractor.
Ideally , maybe....but that is not often practical and not the way farmers have been hauling loads even back with horse and carts.
The normal trick is to get weight transfer from the trailer to the tractor, by the correct location of the load relative to the trailer axle. The “drawbar hitch load” on an Ag trailer can be very high (tons ?)

Re: Electric tractor motors

Posted: Jul 29 2021 7:01am
by speedmd
500 gallons is a big tank and would require a very large vehicle to carry onboard.

300 gallon trailer
Image

500 gallon
Image

As long as it is a short trip to the filling station, it may be better to make several trips with a smaller tank, or have two smaller tanks (one filling while one is being used) than to wait to fill one large tank depending on water source capacity.

Re: Electric tractor motors

Posted: Oct 13 2021 4:32pm
by G8trwood
500 gallons… what is the load capacity of water truck chassis? 5T?
Trailer or 6x6 with the lowest load height you can manage. And brakes! Lot of momentum on a grade!
For the ultimate. Trailer with powered wheels all connected to the vehicle controller;)