Motor combination to drive multiple tyres

• Jay1298
In summary: For example, if you have a motor that produces a lot of torque and you connect it to a wheel that needs a lot of torque too, the wheel will get overloaded and may start to spin too fast or not at all.

Jay1298

If I need 50,000 Nm of torque to rotate a wheel, and I am rotating it about its rim (like the London eye), would 5 10,000 Nm motors each connected to a set of tyres to rotate it (the motors are not connected to each other), or would these motors first need to be connected to each other and then drive a set of tyres or would I need a single 50,000 Nm motor connected to a set of tyres?

Thank you.

Hello Jay,

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 !

Jay1298
The plan is to split the 10,000 between 4-5 tyres
BvU said:
Hello Jay,

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 !

My reasoning: accelerating a 1000 kg car with 4 m/s2 requires 1000 N per tyre.
With a radius of 0.25 m that is 250 Nm of torque per wheel

BvU said:
My reasoning: accelerating a 1000 kg car with 4 m/s2 requires 1000 N per tyre.
With a radius of 0.25 m that is 250 Nm of torque per wheel
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.

But you said you needed 50000 Nm ?

Jay1298 said:
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.
Yes we are going to have 5 10,000 Nm motors each connected to 4-5 tyres

Still don't understand: your final angular velocity is ##\displaystyle{{2\pi\over 24.17 * 60 }\approx 0.0043} ## rad/s. If you reach that in 180 s, your angular acceleration is 2.4 10-5 rad/s2.

With 50 kNm you could handle a moment of inertia of 2.1 109 kg##\cdot##m2 which I guess is not far from the London eye !?

Jay1298
BvU said:
Still don't understand: your final angular velocity is ##\displaystyle{{2\pi\over 24.17 * 60 }\approx 0.0043} ## rad/s. If you reach that in 180 s, your angular acceleration is 2.4 10-5 rad/s2.

With 50 kNm you could handle a moment of inertia of 2.1 109 kg##\cdot##m2 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*109
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.

https://www.patana.ac.th/parents/curriculum/Physics_K5/units/010304.html. With 1900 tonnes and 70 m radius London eye has ##I = ## 9.3 109 kg##\cdot##m2.

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.

BvU said:
https://www.patana.ac.th/parents/curriculum/Physics_K5/units/010304.html. With 1900 tonnes and 70 m radius London eye has ##I = ## 9.3 109 kg##\cdot##m2.

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

Just a heads up...you can have problems with asymetric load sharing if you connect some types of motors in parallel.

1. What is a motor combination to drive multiple tyres?

A motor combination to drive multiple tyres is a set-up in which multiple motors are used to power or drive multiple tyres or wheels. This setup is commonly used in vehicles such as cars, trucks, and motorcycles, as well as in industrial and agricultural machinery.

2. How does a motor combination to drive multiple tyres work?

In a motor combination to drive multiple tyres, each motor is connected to a specific tyre or wheel. When the motors are activated, they rotate the tyres or wheels, which in turn propels the vehicle or machinery forward or backward. This allows for better traction and control, especially in rough or uneven terrain.

3. What are the advantages of using a motor combination to drive multiple tyres?

There are several advantages to using a motor combination to drive multiple tyres. These include improved traction, better handling and control, increased power and torque, and the ability to drive on various terrains. This setup also allows for better weight distribution, which can improve the overall performance of the vehicle or machinery.

4. How many tyres can be driven by a single motor combination?

The number of tyres that can be driven by a single motor combination depends on the size and power of the motor and the weight of the vehicle or machinery. In general, a motor combination can drive up to four tyres, but larger vehicles or machinery may require more motors to properly drive all of the tyres.

5. Are there any limitations to using a motor combination to drive multiple tyres?

One limitation of using a motor combination to drive multiple tyres is the added complexity and cost of the setup. It also requires regular maintenance and may be more prone to failure compared to a single motor driving a single tyre. Additionally, this setup may not be suitable for all types of vehicles or machinery, and the weight distribution may need to be carefully considered to avoid imbalance or instability.