Stopping a rotating cylinder

In summary, the torque required to stop and reverse a spinning cylinder of water in a laundry wash machine can be calculated using the equation T = F x r, where F is the force of the load on the spinning cylinder and r is the radius of the drive pulley. The angular acceleration can be calculated using the equation @ = (T/I), where T is the torque and I is the moment of inertia of the spinning cylinder. The moment of inertia can be calculated using the equation I = mR2, where m is the mass of the spinning cylinder and R is its radius.
  • #1
billinr
15
0
The issue I have is in a system design where I need to find the torque requirement to stop and reverse direction on a spinning cylinder of water (laundry wash machine). The system data I have:

Homework Statement


Water filled cylinder, 564mm diameter
Given weight of load is 170lbs
Spinning at 95 RPM for 1 second, decelerate for 0.25 seconds, reverse direction to 95 RPM
Repeat
Drive Pulley (where torque is applied) is 250mm diameter


Homework Equations



T=@I
Where T= torque, @=angular accel, I=inertia (?)

The Attempt at a Solution


Couldn't say because I really have no idea. (this was far from my strong classes many years ago!)
The force of the spinning drum pushes the drive belt along, and causes it to slip on the motor. I am tasked with finding the correct belt to compensate for the load. I am able to develop the belt mechanics, but I am lost on how to find the forces on the pulley resulting from the moving drum load.

Any help in finding this value would be appreciated
 
Physics news on Phys.org
  • #2
. The torque required to stop and reverse the spinning cylinder can be calculated using the equation:T = F x r,where F is the force of the load on the spinning cylinder and r is the radius of the drive pulley. Using the given data, the torque required can be calculated as follows:T = (170 lbs) x (0.125 m)T = 21.25 Nm To calculate the angular acceleration, use the equation:@ = (T/I),where T is the torque and I is the moment of inertia of the spinning cylinder. The moment of inertia can be calculated as follows:I = mR2,where m is the mass of the spinning cylinder and R is its radius. Using the given data, the moment of inertia can be calculated as follows:I = (170 lbs)(0.282 m)2I = 15.51 kgm2 Therefore, the angular acceleration can be calculated as follows:@ = (21.25 Nm)/(15.51 kgm2)@ = 1.37 rad/s2
 
  • #3
.

I would approach this problem by first calculating the inertia of the rotating cylinder filled with water. This can be done using the formula I = 1/2 * M * R^2, where I is the moment of inertia, M is the mass of the cylinder (including the water), and R is the radius of the cylinder.

Once the inertia is calculated, I would then use the equation T = I * @, where T is the torque, I is the moment of inertia, and @ is the angular acceleration. Since we know the desired angular acceleration (to stop and reverse the direction of the cylinder), we can use this equation to calculate the required torque.

To determine the forces on the pulley resulting from the moving drum load, we can use the equation F = ma, where F is the force, m is the mass, and a is the acceleration. In this case, the force would be the weight of the load (170lbs) multiplied by the acceleration of the drum (which can be calculated using the angular acceleration and the radius of the drum).

Once we have calculated the required torque and the forces on the pulley, we can then use this information to select the appropriate belt to compensate for the load and ensure smooth operation of the system. It may also be helpful to consult with a mechanical engineer for further assistance in selecting the correct belt for the system.
 

1. How does a rotating cylinder create energy?

A rotating cylinder creates energy through rotational kinetic energy, which is the energy an object has due to its rotation. This energy can be harnessed and converted into other forms, such as electrical energy.

2. What are the main methods used to stop a rotating cylinder?

The main methods used to stop a rotating cylinder include friction, braking systems, and energy dissipation through air resistance or mechanical resistance.

3. Can a rotating cylinder be stopped instantly?

No, it is not physically possible to stop a rotating cylinder instantly. This is due to the conservation of angular momentum, which states that an object in motion will continue to move at a constant rate unless acted upon by an external force.

4. What are the potential dangers of stopping a rotating cylinder?

The potential dangers of stopping a rotating cylinder depend on the size and speed of the cylinder. In industrial settings, stopping a large, high-speed cylinder can pose a risk to workers if proper safety measures are not in place.

5. Are there any potential consequences of stopping a rotating cylinder too quickly?

Yes, stopping a rotating cylinder too quickly can cause damage to the cylinder or any attached components. It can also create excessive heat and stress within the cylinder, potentially leading to mechanical failure.

Similar threads

  • Introductory Physics Homework Help
Replies
22
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
3
Replies
78
Views
7K
  • Introductory Physics Homework Help
Replies
33
Views
964
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
22
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
1K
Back
Top