Power train calculations question

In summary: Remember the power to weight ratio also plays a big role in accelerating a vehicle and will be discussed in more detail in another article.
  • #1
wasfy8
4
0
hi,
i have some problems in power train calculations for a small race car has a chain instead of crank shaft converting motion to the rear side, calculating torque on the axle and wheels, forces and the acceleration of the car.
So, can anyone help or mention a guide reference ?
thank you
 
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  • #2
Can you post a specific question regarding your problem, or the things you are trying to work out?

It's difficult to determine exactly where you need help. From what I can gather, you know the engine outputs, but have a chain/sprocket driving a solid axle. Did you mean propshaft and differential rather than crankshaft?

So it sounds like a Kart, or a motorbike driven single seater or similar.
 
  • #3
this is exactly what i mean
need to calculate the torque on the wheel and the acceleration of the car
 

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  • #4
Sprockets, pulleys and gears all work in the same way with regards to torque multiplication. The ratio between inputs and outputs determine the change in speed and torque.

You can calculate your acceleration from the power output, unless you are factoring in losses at each stage.
 
  • #5
Can anyone help me to calculate the power train calculations...




http://www.emfocus.co.in/automotive-powertrain.html
 
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  • #6
I think Chris has answered this for the most part. Remember torque is simply a force across a length, therefore if you have documentation and/or technical papers for the engine you should be able to find out the engines peak torque and at what operational speed it is made at. Assuming peak torque to be 50 N/m at 8000rpm for example, and gearbox reduction in a certain gear to be 5:1 then you know gearbox exit torque will be around 250 N/m (if you disregard frictional, heat and noise losses), say your sprokets give a further 2:1 reduction you can assume that you will produce roughly 500 N/m of torque at the rear axle. I have pulled these numbers out of the air but hopefully you get the picture. Calculating acceleration of the vehicle is a much harder task as the engines torque will vary dependent on the speed it is currently running at which will vary as you accelerate through the gears.
 

1. How do you calculate the power train ratio?

The power train ratio is calculated by dividing the number of teeth on the output gear by the number of teeth on the input gear. This ratio gives you the relationship between the speed of the input gear and the output gear.

2. What is the formula for calculating the power output of an engine?

The formula for calculating the power output of an engine is power = torque x angular velocity. Torque is measured in Nm (Newton meters) and angular velocity is measured in radians per second.

3. How do you determine the gear ratio for a specific vehicle?

The gear ratio for a vehicle is determined by dividing the number of rotations of the input gear by the number of rotations of the output gear. This can also be calculated by dividing the speed of the output gear by the speed of the input gear.

4. What are some factors that can affect power train calculations?

Some factors that can affect power train calculations include friction, air resistance, weight of the vehicle, and the efficiency of the engine. These factors can vary depending on the specific vehicle and driving conditions.

5. Can you explain the concept of gear reduction in power train calculations?

Gear reduction is the process of using gears to decrease the speed of rotation and increase the torque of an engine. This is often used in vehicles to improve their performance, for example, when climbing steep hills or towing heavy loads.

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