Car electric power steering units?

Keep looking at these units .

Maybe too much surgery to fit on tractor, but think easy fit to combine!

How do they work? How would you use it? Doesn’t it just function as a torque generator, much like ah hydraulic unit would work? In other words you still have to turn the steering wheel and this just assists it, correct?

Bing video jump to point 4.46 !

This would just be in-between the steering wheel and the orbital. (someplace, would need to have one to assess where!)
Throwing away the ecu, driving motor with our drivers and also using the torque sensor to disable auto steering if the steering wheel is turned against the motor.

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Maybe you should leave the ecu and find out what output comes from torque sensor, hopefully pwm from arduino can substitute torque sensor(switch to shift between those). Reason: When motor not powered, steering wheel movement goes through planetary gear and maybe you have to turn steering wheel more times than output from planetary gear, as shown at the end of the movie.

That’s genius how they arrange those gears. It’s essentially a CVT that combines your steering wheel torque with the torque of the steering motor. It also explains how they can vary the steering ratio.

Would you need to lock the steering wheel solid so the motor can do all the turning itself?

Really don’t know about locking steering wheel, these auto steering cars must not lock the wheel though?
Only did a search on eBay for steering motor yesterday looking for broke gps units…didn’t even know anything about electric power steering until pages of these units popped up!

Bit concerning that we rely on electronics not to put us in the ditch at 70+mph!

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Well like Larsvest says, the planetary gear arrangement allows the steering wheel to still control the rack and pinion even if the motor fails completely. But either way it’s proven quite reliable over the years, just like hydraulic power assist before it.

I’ve never rode in a self-driving car of any kind, so I don’t know if the steering wheel moves when it’s driving itself. I imagine that it does move, unlike our tractors with pure hydraulic steering.

Steering wheels should be relegated to history, It’s 2020, our cabs would be so much more ergonomic without wheels and our screens in front of us, manual steering, when needed, controlled by a Pot on the armrest.
To retrofit older machines use a pwm valve or geared electric motor direct onto the orbitrol.
Happy new year.


Do you know this full electrical steering unit by SKF? Would probably pose a problem as far as safety / road regulation…!

Good explanation for electrical “assisted” steering:

Fine ÂŁ30 mess I got my self!!IMG_20200108_114122
3 wires to the motor!..2 speed?
There’s 6 MOSFET’s.
Don’t get me started on all the sensor wires!

Looks like it’s a brushless DC motor. 3 wires and 6 FETs (3 phases, one FET for each direction per phase) is the giveaway. Looks like it could be a completely closed loop control board. Is there a torque sensor built into it? Any control wires?

The good news is that in the RC model world, they’ve been dealing with brushless DC motors for many years. Would need an electronic speed controller for brushless, but one capable of reversing direction. Not quite sure where to find one, but I know folks build their own brushless gimbal mounts, so they must exist.

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Wire arrowed on the left goes to steering wheel toque sensor, but must plug in elsewhere!
Wire’s going to motor must do similar.
Haven’t dug too deeply yet.

After research… Wires on right will be to/from hall sensor’s.

Here’s a reversible ESC that’s rated for at least 70 amps. Should be able to directly drive the motor using a pwm signal from Arduino.

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They only have a 7.5amp fuse shown in any info I have found online!? Think 70 many be over kill!

There are smaller ESCs, but the trick is to find one that is reversible. Toy trucks typically use such ESCs. Aircraft ESCs tend to be one direction only.

EDIT: changed to show sensored ESC:

$24, not too bad.

Hmm, the wrinkle is that the power steering motor looks like it’s a sensored motor. You can see bunch of smaller wires coming off the motor that plug into the board. It’s probably a standard sensor configuration (seems like most are), so it would probably work with an RC ESC, provided it is a sensored ESC.

Sensored ESCs are a bit more expensive.

Thanks…I’d actually worked that out, but was unsure if it would work with straight esc?

In theory all that should already be on that board…just need some reverse engineering!!