- #1

Jay1298

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Thank you.

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- #1

Jay1298

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Thank you.

- #2

BvU

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The total torque is simply the net (vector) sum of the torques applied, so it isn't necessary to connect the motors or have only a single one.

My first guess is that 10000 Nm is way too much to ask from a tyre, but you may have better info.

Good luck with your design !

- #3

Jay1298

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The total torque is simply the net (vector) sum of the torques applied, so it isn't necessary to connect the motors or have only a single one.

My first guess is that 10000 Nm is way too much to ask from a tyre, but you may have better info.

Good luck with your design !

- #4

BvU

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With a radius of 0.25 m that is 250 Nm of torque per wheel

- #5

Jay1298

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I understand but our acceleration is tiny, the wheel runs at 1 revolution per 24.17 minutes and an acceleration time of around 3 minutes, giving an angular acceleration of something like 10^-5 if I remember right.^{2}requires 1000 N per tyre.

With a radius of 0.25 m that is 250 Nm of torque per wheel

- #6

BvU

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But you said you needed 50000 Nm ?

- #7

Jay1298

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Yes we are going to have 5 10,000 Nm motors each connected to 4-5 tyresI understand but our acceleration is tiny, the wheel runs at 1 revolution per 24.17 minutes and an acceleration time of around 3 minutes, giving an angular acceleration of something like 10^-5 if I remember right.

- #8

BvU

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With 50 kNm you could handle a moment of inertia of 2.1 10

- #9

Jay1298

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^{-5}rad/s^{2}.

With 50 kNm you could handle a moment of inertia of 2.1 10^{9}kg##\cdot##m^{2}which I guess is not far from the London eye !?

My mistake with the numbers i didn't have access to exact numbers of our project when writing this thread so I used approximations, here are my workings:

The time to accelerate is 240 s

The angular velocity is 0.00433 rad/s

The inertia is 4.3*10

Therefore the torque needed is 77500 Nm approx.

This is spread over 8 motors so for simplicity let's say 10,000 Nm per motor, each motor will drive 4 x 0.5m radius tyres.

- #10

BvU

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Your thingy half that ##I## ? If so, I agree with your calculations. Still worry about 5000 N per tyre, but I suppose truck tyres manage it too.

- #11

Jay1298

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^{9}kg##\cdot##m^{2}.

Your thingy half that ##I## ? If so, I agree with your calculations. Still worry about 5000 N per tyre, but I suppose truck tyres manage it too.

Yes we are planning on using big tyres, and our radius is 50m

- #12

CWatters

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