How Much Torque is Required to Rotate a Drum at 6500 RPM?

Click For Summary

Discussion Overview

The discussion revolves around determining the torque required to rotate a drum at 6500 RPM, considering the mass of the drum, shaft, and load. Participants explore the implications of high rotational speeds in the context of an engineering design project focused on food drying. The conversation includes considerations of stability, material selection, and design requirements.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks guidance on calculating the motor power needed to rotate a drum and shaft system at 6500 RPM.
  • Another participant questions the feasibility of achieving such a high rotational speed, emphasizing the importance of system balance to prevent vibrations.
  • Concerns are raised about the stresses on the bearings and drum structure at high speeds, with a suggestion to consult real-world designs for centrifugal food drying.
  • Participants discuss the diameter calculation for the shaft, with one participant proposing a diameter of 43mm based on SS304 material.
  • There is a suggestion to consider using multiple roller supports instead of a shaft mount to better handle unbalanced loads.
  • Some participants express uncertainty about the balancing aspect and its impact on design, with a request for guidance on calculating the shaft's diameter while ignoring balancing issues.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of achieving 6500 RPM, with some considering it too difficult without proper balancing, while others seek to understand how to proceed with the design under the given constraints. No consensus is reached regarding the appropriate RPM or the design approach.

Contextual Notes

Participants highlight limitations in their understanding of real-world applications and the potential consequences of ignoring balancing issues in their design. There is also a lack of clarity on the design requirements set by the instructor.

Who May Find This Useful

Students and professionals involved in mechanical design, particularly those interested in high-speed rotational systems and their stability considerations.

PatPat
Messages
5
Reaction score
0
I need to make sure that my drum which is connected to a shaft and with load of 30kg is able to rotate at 6500rpm.

mass of drum : 15kg, diameter 0.6m, length, 0.6m
mass of shaft : 11kg, length = 1m, diameter, 0.043m
mass of load : 15kg
desired speed : 6500rpm in 30minutes.

How can I determine my motor power that can turn my system? Can someone guide me with my problem?
 
Engineering news on Phys.org
PatPat said:
I need to make sure that my drum which is connected to a shaft and with load of 30kg is able to rotate at 6500rpm.

mass of drum : 15kg, diameter 0.6m, length, 0.6m
mass of shaft : 11kg, length = 1m, diameter, 0.043m
mass of load : 15kg
desired speed : 6500rpm in 30minutes.

How can I determine my motor power that can turn my system? Can someone guide me with my problem?
Welcome to the PF. :smile:

That's a pretty fast rotational speed for that mass. What is the application? How are you ensuring a balanced system so that vibration does not tear it apart?

What is your background in mechanical design? Have you done this sort of project in the past?
 
  • Like
Likes   Reactions: wormbread
berkeman said:
Welcome to the PF. :smile:

That's a pretty fast rotational speed for that mass. What is the application? How are you ensuring a balanced system so that vibration does not tear it apart?

What is your background in mechanical design? Have you done this sort of project in the past?
Thank youu!

Its for my engineering design project . A high rotational speed drum to dry food. We are working in a group and we just need to create a simulation. Not the actual thing. I'm not sure about the balancing stuff as we're not stressed on such issue.

My part was to design the shaft for the drum dryer (the most important thing is to determine the shaft's diameter), to determine the mass of the drum and shaft and how many torque is required in order to rotate these three to 6500rpm.
 
I'm not sure if my diameter calculation is even correct, but we're using SS304 as the material. And I calculated roughly about 43mm diameter for the shaft. 1 meter long.

This is my first time working for such project.
 
PatPat said:
Its for my engineering design project . A high rotational speed drum to dry food. We are working in a group and we just need to create a simulation. Not the actual thing. I'm not sure about the balancing stuff as we're not stressed on such issue.

My part was to design the shaft for the drum dryer (the most important thing is to determine the shaft's diameter), to determine the mass of the drum and shaft and how many torque is required in order to rotate these three to 6500rpm.
Well, at that rotational speed, designing for stability is going to be a major part of the project. You will see it in simulation if you do a good enough simulation -- the stresses on the bearings and drum structure will tear the apparatus apart. Whose idea is the 6500 RPM? Is it a design requirement from the instructor for the project? Or is is a number just thrown out there by the students in response to a more basic problem statement.

Do you know what real-world designs use for centrifugal food drying?
 
berkeman said:
Well, at that rotational speed, designing for stability is going to be a major part of the project. You will see it in simulation if you do a good enough simulation -- the stresses on the bearings and drum structure will tear the apparatus apart. Whose idea is the 6500 RPM? Is it a design requirement from the instructor for the project? Or is is a number just thrown out there by the students in response to a more basic problem statement.

Do you know what real-world designs use for centrifugal food drying?

Yeah it's the design requirement set by our lecturer. I'm not sure myself about those kind of stresses, as I have very low exposure to real life design and application.

Sadly but no ;/

However, just IF we're to ignore the balancing part, can you please give me a jump start to calculate for the shaft's diameter?
 
PatPat said:
Yeah it's the design requirement set by our lecturer. I'm not sure myself about those kind of stresses, as I have very low exposure to real life design and application.

Sadly but no ;/

However, just IF we're to ignore the balancing part, can you please give me a jump start to calculate for the shaft's diameter?
Sorry, I'm not comfortable ignoring the balancing issue. That will cause you to use a much bigger diameter shaft and drum structure. Could you please run this question by your instructor?

And see if you can find out what RPM is used by typical centrifugal food dryers like these:

https://www.google.com/search?q=cen...3gP_TAhVQ8GMKHeArCjMQsAQIlgE&biw=1244&bih=897

I could see maybe 600 RPM withe a moderate amount of balancing effort, but 6500 RPM seems way too difficult to me. But others here may have other opinions...
 
berkeman said:
Sorry, I'm not comfortable ignoring the balancing issue. That will cause you to use a much bigger diameter shaft and drum structure. Could you please run this question by your instructor?

And see if you can find out what RPM is used by typical centrifugal food dryers like these:

https://www.google.com/search?q=cen...3gP_TAhVQ8GMKHeArCjMQsAQIlgE&biw=1244&bih=897

I could see maybe 600 RPM withe a moderate amount of balancing effort, but 6500 RPM seems way too difficult to me. But others here may have other opinions...

But let's just assume that my instructor give a what you would say a recommended rpm. Can you guide me on how to design the diameter? Which way should I start looking at.
 
  • #10
Rather than shaft mount this system, have you considered using multiple roller supports? This will take an unbalanced load much more easily than a shaft in bending.
 
  • Like
Likes   Reactions: Tom.G and berkeman

Similar threads

Analytical mathematical modeling of the torque caused by the laundry
  • · Replies 6 ·
Replies
6
Views
3K
Torque Required to Rotate a Drum
  • · Replies 12 ·
Replies
12
Views
12K
How Much Torque is Required to Rotate a 1500lb Steel Drum?
  • · Replies 7 ·
Replies
7
Views
6K
Design of Shaft Diameter for a rotating Drum
  • · Replies 1 ·
Replies
1
Views
5K
Torque calculations: Rotating vertical shaft
  • · Replies 5 ·
Replies
5
Views
5K
How to Measure Torque Required for motor to spin a rotating shaft?
  • · Replies 3 ·
Replies
3
Views
5K
Maximum torque required to turn the wheel along the vertical axis
  • · Replies 9 ·
Replies
9
Views
2K
High School Calculating the torque needed to rotate a drum
  • · Replies 4 ·
Replies
4
Views
3K
Torque required to rotate a hollow cylinder containing chips
  • · Replies 5 ·
Replies
5
Views
2K
How to calculate required torque for a robot arm
  • · Replies 2 ·
Replies
2
Views
4K