[tomthumb]

My son had a jaguar and the cost of replacing the failed brakes were too much to warrant keeping the car.

Other solutions:

1. Modify the suspension so it is closer to the center of the car, which would allow both the wheel motor and disc.
2. Extend the body of the car to cover the wheel. This would work in my Saab Sonett, since it has a fiberglass body and easily modified.

One of the most commonly mentioned problems with wheel motors is that they increase the unsprung weight of the car. If we get rid of the driveshafts that should compensate some. If we get rid of the disc brakes and use the motors to provide active and passive braking (reverse power or just sending the power generated by the wheel motor to the batteries) the weight could be reduced even more.

[WheelMotor]

I have seen this Michelin WM a few times, but apparently overlooked the claimed Kws of the thing.
So they have achieved 30Kw out of a motor the size of ... what ? my fist ?
Estimated by the ratio between the rim diameter and the electric motor it will not be more than 10 cm (3.9 inch) of diameter. Also NO COOLING visible ???
At 90 % efficiency this motor will also produce 3 kw of heat.
Have you ever seen a motor of 30 KW ? That's (in the real world) a beast of at least 200 kg (440 lbs). They also are specifying that it is "continuous" power.
Go here to see what a 30Kw asynchronous motor of the company Baldor looks like. It is 19 inch (25Cm) wide by 33 inch (85Cm) long and weights 709 lbs (320kg).
So if the Michelin wonder boys managed to make that engine of a "negligible weight", so that it can be fitted together with a lot of other components (one has even to search for it in that complex setup) than that is really really an invention !
I am astonished. Can anybody comment on this ?

[JRP3]

First off you don't want to compare the power and weight of an industrial motor meant to run for days or months under load to an EV traction motor. Tesla gets a lot more power, over 180KW max, from a 75 lb motor.
Second, the Michelin motor obviously uses gear reduction so that has to be added in to the weight, the entire assembly with suspension is around 95lbs. This is not to say that I don't think it's impressive, just that comparing it to a 400lb. industrial motor isn't very accurate.

[WheelMotor]

If comparing the power of electric motors, we have to look at how long this power can be asked from that motor. In the case of this Michelin wheel they explicitly mention: Continuous Power
To squeeze 30 Kw for lets say an hour out of an electric motor the size of a can of beans, without any (visible) cooling or liquid cooling piping connections that is ... more than amazing !
The comparison with an industrial motor is only to put things a bit in perspective. Although providing this power for a 3 hours blast over the German Autobahn from let's say Bremen to Munich, a 600 Km stretch, at let's say 200Km/H one could also consider "an industrial application" .

[Woodsmith]

Interesting read about in wheel motors.

I do have some ideas that challenge the accepted norm but as WheelMotor is a commercial enterprise I will refrain from giving away anything that may end up as a commercial venture for someone else.

No offence meant WM but I have been caught out discussing what I thought was my design and going open source but for the other person to build my idea and sell it as a private venture.

[IamIan]

On the issue of cooling ... I don't think it is as big a deal as suspected.

Most brakes produce over 100kW of braking power with almost 100% of it being converted to heat... only tiny bits as light, and sound, etc...

Yes, the brakes are not needed to do this for overly long extended periods of time but they can still do it for as long as the engineer that built them, needed them to...

similarly 30kW per Wheel x4 wheels = 120kW .... that kind of power is only need during acceleration , which is always short lived for only a few seconds... or for a large heavy unaerodynamic vehicle traveling at high speeds.

Don't get me wrong... cooling matters and is important ... but the duration of the heating event in application is far more important than the amount of heat generated.

[CroDriver]

Even if the IW motors get affordable there's another problem... You would need four controllers for a car.

It's hard for me to believe that IW motors will be common soon

[WheelMotor]

As you can see here Volvo too abandoned the in wheel motor in it's latest version of the electric C30.

[major]

Originally Posted by WheelMotor

Major,

you are a pessimist . Within a few months I will be back here with a video of a prototype installed in a car. Than we speak again !

Hi there Mr. WheelMotor,

A year since you called me a pessimist. Not much progress, is there? Thinking about changing your name?

The in-wheel motor seems like a good idea on the surface. So it becomes a product everyone wants. But nobody has been able to deliver. Why is that? Maybe it isn't really a good idea after all. If the in-wheel motor actually was a great idea, why then isn't the in-wheel internal combustion engine?

Regards,

major

[IamIan]

Originally Posted by major

If the in-wheel motor actually was a great idea, why then isn't the in-wheel internal combustion engine?

I don't follow.

Why would the presence or lack of a internal combustion engine wheel motor have anything at all to do with the viability of an electric wheel motor?

-----------------------

To be sure there are a variety of issues to deal with for wheel motors. Just like there are a variety of issues to deal with any motor.

Maybe it will be a long time before all those issues are dealt with. But the issues have already been dealt with in some applications where the electric wheel motor is already used heavily.

I see the electric wheel motor as an eventuality ... kind of like going to EVs as an eventuality ... There are inherent advantages to that system ... issues or no ... it is only a matter of time.

Of course I hope it is sooner than latter.