Controlling torque output from a flywheel

In summary, the conversation discusses the need for a component that controls the torque output from a flywheel to maintain a constant speed. The suggested solution is to use a clutch, which can be controlled through friction to achieve the desired torque output. The conversation also mentions the use of a continuously-variable transmission (CVT) or fixed gear ratio as alternative solutions, and discusses the process of using the flywheel system to power a load.
  • #1
MichelKS
8
0
Question
Is there a component that controls the torque output from a flywheel so that its output is constant?

Context:
Parts:

1) An engage/disengage switch
2) A cable reel
3) A flywheel
4) A mechanism to control the torque output from the flywheel.

Process
When the switch is engaged, the flywheel transfers a constant amount of torque to the reel and the reel winds the cable.
When the switch is disengaged, the flywheel spins freely and no torque is transferred to the reel.
 
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  • #2
MichelKS said:
Question
Is there a component that controls the torque output from a flywheel so that its output is constant?

Context:
Parts:

1) An engage/disengage switch
2) A cable reel
3) A flywheel
4) A mechanism to control the torque output from the flywheel.

Process
When the switch is engaged, the flywheel transfers a constant amount of torque to the reel and the reel winds the cable.
When the switch is disengaged, the flywheel spins freely and no torque is transferred to the reel.

Welcome to the PF.

What is the context of the question? Is it for schoolwork? There is indeed such a mechanism...
 
  • #3
No, not for school work. Just a tool I want to build.
 
  • #4
MichelKS said:
No, not for school work. Just a tool I want to build.

Okay, fair enough. What mechanism is used to transfer power from a car's engine (which contains a flywheel) to the drive wheels?
 
  • #5
The transmission?

I suppose the clutch would decouple the flywheel from the reel?
 
  • #6
Yes, the clutch is what I was asking for. The only tricky part of your question is to control the clutch so that the output torque is constant. You will need some way to measure the output torque, and use feedback to control the clutch pressure to maintain the target torque.

If you know the moment of inertia of the output that you are driving, you can use this equation:

[tex]\tau = I * \alpha [/tex]

Are you familiar with that equation about angular acceleration?

What is the thing you are driving with this? Will it be turning at a constant speed when the output torque is constant? Or will it be accelerating for some period of time?
 
  • #7
It will be a constant speed.
 
  • #8
MichelKS said:
It will be a constant speed.

So you just servo the clutch to maintain that constant speed. Done!
 
  • #9
BTW, is your flywheel getting energy input from an engine, so that it will maintain a constant speed too? If so, you could just put a continuously-variable transmission (CVT) between the flywheel/motor and the thing you want to drive at a constant speed. Or even a fixed gear ratio if the relative speeds will be known ahead of time...
 
  • #10
Perfect =) Thanks for helping.
 
  • #11
berkeman: what does the phrase 'servo the clutch' mean? Are you referring to clutches commonly referred to as 'torque converters' with a turbine and pump mechanism OR to the usual friction clutch? And if so, what did you mean by that phrase in your context of the clutch?
The torque curves are usually parabolic shaped w.r.t engine speed in IC engines, peaking at a certain engine speed.So, How would the clutch make the torque output constant?
 
  • #12
marellasunny said:
berkeman: what does the phrase 'servo the clutch' mean? Are you referring to clutches commonly referred to as 'torque converters' with a turbine and pump mechanism OR to the usual friction clutch? And if so, what did you mean by that phrase in your context of the clutch?
The torque curves are usually parabolic shaped w.r.t engine speed in IC engines, peaking at a certain engine speed.So, How would the clutch make the torque output constant?

A clutch commonly used in a vehicle where there are 2 foot peddles - one for the brake and one for the clutch ( a third is the accelerator ).
The clutch operates by friction. By engaging the clutch so that it slips less or more one can control the torque applied to the drivetrain down the line.
A fully engaged clutch would transmit the engine torque curve.

Torque is force multiplied by the radius, so a controlled variable friction force between the clutch plates can control the torque.
 
  • #13
berkeman said:
Will it be turning at a constant speed when the output torque is constant? Or will it be accelerating for some period of time?

I may have been wrong about it turning at a constant speed. The force output needs to remain constant, so if the load decreases then the reel would need to accelerate, correct?

The system might be built like this

Manual crank (energy in) -> Flywheel -> clutch? -> reel -> cable/rope/etc -> load

In use it would proceed like this:
1.The user will crank the flywheel
2.The user sets the amount of torque he wants from the system
3.He waits for an event outside the system
4.When that event occurs, the user engages the flywheel with the reel
5.The reel then pulls on the load
6.The user waits for another event, then disengages the flywheel from the wheel.
7.Repeats steps 3-6 until flywheel is out of energy or user stops process.

The load may change during operation, but the cable must always apply the amount of force set by the user.
 
Last edited:
  • #14
marellasunny said:
berkeman: what does the phrase 'servo the clutch' mean?

I just meant use feedback to control the clutch pressure to get the output torque characteristic that is desired.
 

What is a flywheel?

A flywheel is a mechanical device that stores rotational energy. It consists of a heavy disc or wheel that is mounted on a shaft and allowed to rotate freely. Flywheels are commonly used in machinery and vehicles to maintain a steady and consistent energy output.

How does a flywheel control torque output?

A flywheel controls torque output by storing kinetic energy when it is rotating at a high speed and releasing it when the speed decreases. This helps to maintain a constant rotational force and smooth out any fluctuations in energy output.

What factors affect the torque output of a flywheel?

The torque output of a flywheel can be affected by several factors, including the size and weight of the flywheel, the speed at which it is rotating, and the amount of energy being supplied to it. Friction and air resistance can also impact the torque output.

How can the torque output of a flywheel be adjusted?

The torque output of a flywheel can be adjusted by changing the weight or size of the flywheel, altering the speed at which it rotates, or adjusting the amount of energy being supplied to it. Additionally, adding or removing friction can also impact the torque output.

What are some common applications of controlling torque output from a flywheel?

Flywheels are commonly used in machines and vehicles where a consistent and smooth energy output is necessary. They are also used in gyroscopes, electric motors, and power plants to help regulate power and prevent fluctuations. Additionally, flywheels are used in sports equipment, such as bicycles and exercise machines, to maintain a constant resistance and provide a smoother workout experience.

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