Is it possible to change the Torque in a gearbox by altering the inertia?

In summary: If that's not possible, then you will have to change the gear ratio to achieve the desired increase in output torque. Changing the gear arrangement or tooth area will not have a significant impact on the output torque. In summary, the conversation discusses the concept of torque in a gearbox and the factors that affect it, such as gear ratio and moment of inertia. The conversation also explores the possibility of increasing the output torque without changing the gear ratio, but it is concluded that this is not possible and compromises must be made in accordance with the laws of physics.
  • #1
Number_19
5
0
Hello guys, I am new here =)

After looking everywhere on Google, I have decided to create an account and give this a shot!

I am trying to understand the concept of Torque generated by a gear box (simple gearbox with 2/3 gears, nothing fancy). I understand that changing the gear ratio changes the Torque of a gear box. More specifically, one creates a reduction gearbox, the Torque increases.

Ok then, now I am wondering:

Keeping in mind this formula:

T = I [tex]\alpha[/tex]

where T= Torque, I = moment of Inertia, and [tex]\alpha[/tex] = angular acceleration

Does it mean that if one changes the moment of Inertia of a gear the Torque changes too?!

More specifically, does it mean that one could increase the Torque being produced by a gearbox by simply increasing the Area/Size of the gears itself (with no need of changing the ratio)?

Thank you for your time, and please let me know if I need to make this any clearer!

Regards
N19!
 
Engineering news on Phys.org
  • #2
Your formula is helpful for understanding acceleration. For example, if you had a flywheel at rest (whose moment of inertia is known), the formula describes how much torque is required to cause the flywheel to gain speed at a certain weight. If the inertia is decreased (like on a racing car with a small flywheel), for a given torque its acceleration will be higher.

Don't confuse this with the output torque of a gearbox under constant speed conditions. Look back through this forum, there was a recent discussion on gearbox torque.
 
  • #3
Hello sorry for the delay, and thank you for the answer..

Ok, I have got another question. Would changing the kind of gear (for example from spur to helical, for instance) have any effect on the Torque?!

Thank You once again!

Regards
N19
 
  • #4
Not really. It's the gear ratio which makes the real difference.
 
  • #5
Hmm that sux..I was hoping there would be a way to change the torque (even just slightly) by not changing the ratio.

Thank You all!
 
  • #6
Why do you want to?

You can reduce the output torque by reducing the input torque. Share what you're trying to do and we should be able to help out.
 
  • #7
If you make the gears lighter or smaller (decrease their moment of inertia) then you will have slightly more output torque available when accelerating...because less torque will be used to accelerate the gears themselves.
 
  • #8
To Brewnog, all it is:

Well its a small project where I need to increase the torque of a gearbox.

I could do it easily by increasing the gear ratio. But I would like to try keep the gear ratio the same if possible.

Thank You!
 
  • #9
Do you mean the output torque?

You could use a system of pulleys and belts to reduce the output torque of the gearbox, or rubber wheels in place of gears, but you can't bend the laws of physics here. The product of output speed and torque is equal to the product of input speed and torque (less inefficiencies). You can't magically increase the torque without reducing the speed. Failing that, increase the input torque.

When I asked for your application, it was to better understand what the limitation you have is; why can't you use the same gear ratio? What's the gearbox for?
 
  • #10
Number_19 said:
To Brewnog, all it is:

Well its a small project where I need to increase the torque of a gearbox.

I could do it easily by increasing the gear ratio. But I would like to try keep the gear ratio the same if possible.

Thank You!
You are wanting something for nothing here. You need to make compromises. That is what engineers do. You can not go against the physics.
 
  • #11
To be honest, I am actually not sure what the gearbox is for! However, I know I have to increase the output torque (not decrease) by 20%.

I wanted to see if there was a way to do so without changing the gear ratio, for example by changing tooth area, or gear arrangement..but I guess not!
 
  • #12
You could increase the input torque by 20%.
 

1. Can the torque in a gearbox be changed by altering the inertia?

Yes, it is possible to change the torque in a gearbox by altering the inertia. Inertia is a measure of an object's resistance to changes in its motion, and altering it can affect the overall torque of the system.

2. What is the relationship between inertia and torque in a gearbox?

Inertia and torque are directly related in a gearbox. The greater the inertia, the more force is needed to change the motion of the system, resulting in a higher torque. Similarly, decreasing the inertia will result in a lower torque.

3. How does changing the inertia affect the performance of a gearbox?

Changing the inertia in a gearbox can have a significant impact on its performance. Increasing the inertia can provide more power at lower speeds, while decreasing the inertia can improve the gearbox's responsiveness and efficiency.

4. What factors influence the inertia in a gearbox?

The inertia in a gearbox is influenced by several factors, including the mass and distribution of the rotating components, the gear ratio, and the speed of rotation. Altering any of these factors can change the inertia and, in turn, the torque of the system.

5. Are there any limitations to altering the inertia in a gearbox?

While altering the inertia can have significant effects on a gearbox, there are limitations to consider. Changing the inertia may require modifications to the gearbox design, and it may also affect the durability and longevity of the system. Additionally, there may be limitations based on the specific application and desired performance of the gearbox.

Similar threads

  • Mechanical Engineering
Replies
12
Views
1K
  • Mechanical Engineering
Replies
19
Views
2K
  • Mechanical Engineering
Replies
7
Views
2K
  • Mechanical Engineering
Replies
18
Views
917
  • Mechanical Engineering
Replies
20
Views
9K
  • Mechanical Engineering
Replies
5
Views
3K
Replies
5
Views
1K
  • Mechanical Engineering
Replies
11
Views
2K
  • Mechanical Engineering
Replies
15
Views
4K
Replies
1
Views
9K
Back
Top