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transmission less conversion

9157 Views 62 Replies 11 Participants Last post by  electro wrks

Has anyone done a motor direct connect to driveshaft conversion? What adapters or solutions did you come up with, or anyone know of any examples? I need to go directly from the motor to the driveshaft. Any help be appreciated.

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I don't see what wire size has to do with anything, or whether it's AC or DC for that matter. The motor could care less whether it's "industrial", in a forklift or EV -- it is spec'd as AC or DC, as maximum safe RPM, torque, HP, volts and amps. "Industrial" means nothing in the grand scheme of relevance here. Whether someone's used an AC motor is completely irrelevant and needs design worries revectored to the important stuff.

A fan on a shaft being a characteristic of "industrial" motors is also BS -- a machine tool has a TEFC motor and is VFD rated (harmonics tolerant windings). TEFC is totally enclosed fan cooled...there's a separate motor for a fan that cools the motor. If there wasn't you could never run a CNC milling machine all day at 50RPM while splashing it with chip-filled job coolant as 440V 3 phase is lurking nearby.

"Repurposing" to an EV is meaningless. YOU need to figure out what you want for the vehicle's top speed, the grade of road you want to be able to cruise at, passing reserve, and, if you like bald rear tires, do the math on the torque you need to get the acceleration you want or that will break the tires so you can get all the hot chicks who dig the smell of burnt rubber.

That specification exercise gets flipped on its head when you pick a motor out of a junkpile, salvage one, or happen to have inherited one from your Uncle Martin's estate. At that point you have a motor and a car. You need to either close your eyes and hope for the best, only worrying about HP and top speed, or you do the math, applying nameplate ratings to the car and seeing if it works. In most cases, you'd aim for a top speed for direct drive/gearbox decisions and your 0-60 is what it is. Unless you decide to have several ratios behind the motor, in which case you can eek out a bit more acceleration at lower vehicle speeds.

There's no free lunch in all this. If you don't want to spin the motor at 15 grand, but at 1800 using a direct drive and "industrial" motor, it's going to be a big, heavy, chunk of iron. And, no, a forklift designer doesn't intentionally make the motor heavy -- that's an extremely expensive way to make ballast. S/he's out to make torque in a tight space using a human-safe pack voltage.

There's no such thing as "repurposing" for an EV. It's *purposing* a nameplate rating into a car you already have in mind. If that doesn't work well enough, you play games with overvoltage (which DOES affect the top speed of an AC motor, by the way), spinning it beyond rated limits hoping the shrapnel stays in the engine compartment for the increase in HP, upping the current through the windings (which are correcty sized for the nameplate rating by the manufacturer, not "smaller" because it's "industrial), or using a gearbox.

You either spec the car's performance and find a motor that meets your requirements, or you have a motor and a car, and you get what you get with perhaps a bit of tweaking to squeeze out all you can to better the (usually) craptastic vehicle performance. But it likely won't be a whole lot better and in most cases you'll be building a golf cart that looks like a car because you found a 10HP 3phase 440 volt (which has "smaller" windings) motor on Craigslist.

Building EV's is expensive and is a tradeoff -- you'll either pay the price out of your wallet or in vehicle performance. Unless you are opportunistic and lucky and pick up the pieces you need over several years, after which you're miffed because you bought a brushed DC motor years ago and the world has gone high speed, high voltage, brushless, so you then wait around for one of those to come along (don't ask how this is not a hypothetical scenario).
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Im somewhat little informed on this but Im looking to find a taper lock bushing with the bolt on hub all in a set. Im in the USA so does anyone know companies that sell them as a set? I have an 1 1/8th shaft on my motor. Im just trying to leave the guess work out of it, if any of you know where to get?

Are their any EV companies that sell them, or other good resources to buy them as a unit? I seem to find one place that sells the insert and then another that has the flange to bolt to the other side of the drive line
Are their any EV companies that sell them, or other good resources to buy them as a unit? I seem to find one place that sells the insert and then another that has the flange to bolt to the other side of the drive line
The Taper-Lock bushings(I think that's what you are referring to as an "insert") come in industrial standard sizes with a range of bore diameters for each size. That way a sprocket or flange can fit a range of shaft diameters by changing out the Taper-Lock bushing for one that fits the shaft it's going on.
You seem to have trouble understanding the design concepts of setting up this kind of drive line power transmission system. I suspect in this case you would be wise to have a specialist design and maybe set-up the system. A shop that specializes in custom cars, or a shop that does or sells industrial PT systems does this kind of work on a regular basis. It might be time to bring in a Pro.
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