×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

(OP)
How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia​ 0.4kgm²at end ?

I would say Zero , because of no unbalance Mass on axis of rotation

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

This is a very vague question.

No matter what, if you have a mass directly coupled to the end of any engine's output shaft, the engine is accelerating (or decelerating) that mass. Whether the mass is balanced or not does not matter. The only way for an engine to operate as if the connected machinery has a moment of inertia of zero is if the connected machinery has a moment of inertia of zero- which is impossible.

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

(OP)
@jgKRI

What if the disc is attached to the outputshaft of gearbox, and if you neglect moment of inertia of gearbox and engine? what will be the feeling of MOI due to Disc at Engine

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

Depends on the ratio of the gearbox- but the reflected inertia cannot be zero.

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

engg35mechie,

Moment of inertia has no effect on anything unless acceleration is present. Is your engine running at a steady speed? If torsional vibration is present, your moment of inertia will affect it.

--
JHG

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

Moment of inertia has no effect? So a flywheel on a combustion engine is useless?
Adding an inertia will change the torsional resonance frequencies. I am not sure what side you mean by the "end" (this is usually the flywheel side) but either end, you will change the crankshaft natural frequency and this may cause a serious problem. It may be a good thing, but also cause the crankshaft to be operated at resonance conditions (which will probably break it)

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

rob768,

A piston engine does not run at absolutely steady speed. It accelerates when the piston fires, and it decelerates under load and under piston compression when the pistons are not firing. The flywheel affects this behavior.

--
JHG

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

(OP)
Hallo thank you for your replies..
What if its the servo motor that drives the gearbox

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

engg35mechie,

The inertia through a gearbox is multiplied by the square of the gear ratio.

--
JHG

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

Drawoh, that is exactly why i think any inertia will have an effect. Hence the question marks..

RE: How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia X?

Quote (nengg35mechie)


How much momemt of Inertia will be felt at engine if we attach a disc of moment of inertia​ 0.4kgm²at end ?

I would say Zero , because of no unbalance Mass on axis of rotation

I just re-read your post. You can have a high moment of inertia even if your mass is perfectly balanced. The moment of inertia will affect your acceleration when you apply torque. If this is a servo system, you want a low moment of inertia relative to the motor. Otherwise, it will not respond reliably to feedback.

--
JHG

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

eBook - 10 Reasons to Choose CATIA on the Cloud
To compete in today’s fast-paced and competitive market, smaller and newer firms need a powerful platform that will enable them to compete with bigger players, without the heavy investments needed in computer hardware, software and personnel. Download Now
White Paper - Smart Manufacturing for Electronics
This white paper describes a transformative approach to electronics manufacturing made possible by the addition of Mentor Graphics to the Siemens family. It describes a completely digitalized strategy that supports both printed circuit board (PCB) and mechanical design and manufacturing, uniting the entire product lifecycle – from idea and production to customers and back. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close