কলা
সৌন্দর্য এবং সুস্থতা
ক্রাফট
সংস্কৃতি ও ইতিহাস
বিনোদন
পরিবেশ
খাদ্য ও পানীয়
রিভার্স ইঞ্জিনিয়ারিং
বিজ্ঞান
খেলাধুলা
টেকনোলজি
পরিধানযোগ্য
Balance: A Tiny Eccentricity Becomes an Enormous Force
A smear of paint on one side of a fan, or a fastener replaced with a slightly heavier one, is enough to put a rotor out of balance. Not because the mass is large, but because centrifugal force rises with the SQUARE of the speed.
Double the speed and an unbalance produces four times the force. Which means a rotor that is perfectly acceptable at 500 rpm can be destructive at 3000, from exactly the same small amount of extra mass in the wrong place.
It also means balancing is not optional above a certain speed, and that the tolerance tightens as speed rises. A balance grade is always quoted WITH a speed, and a rotor balanced for one is not balanced for another.
উন্নত
3 hours
নির্দেশ
1
1
The square law, in numbers
The square law, in numbers
Jupyter নোটবুক লোড হচ্ছে…
আবশ্যক উপকরণ:
ডেস্কটপ কম্পিউটার
সূক্ষ্ম দাঁড়িপাল্লা
খাতা2
2
Static and dynamic unbalance are different faults
Static and dynamic unbalance are different faults
STATIC unbalance is a single heavy spot. A rotor on frictionless supports will roll until that spot is at the bottom, which is how it is found without spinning anything, and it is corrected in one plane.
DYNAMIC unbalance is two heavy spots on opposite sides at opposite ends. The rotor balances perfectly at rest — the two cancel — and wobbles violently when it spins, because they form a couple that tries to tumble it.
So a rotor that passes a static check can still be badly out. Anything long relative to its diameter, and anything fast, needs balancing in TWO planes, which means a machine that can measure phase as well as amplitude.
আবশ্যক উপকরণ:
সূক্ষ্ম দাঁড়িপাল্লা
ডায়াল ইন্ডিকেটরখাতা3
3
Unbalance has a signature: once per revolution
Unbalance has a signature: once per revolution
Unbalance vibrates at exactly the rotating frequency — once per revolution, 1X — and it is mostly radial. That signature is what distinguishes it from everything else on a machine.
MISALIGNMENT shows strongly at twice per revolution, 2X, and often has a large axial component. A LOOSE foot shows many harmonics. A failing bearing shows high frequencies unrelated to shaft speed.
So the frequency tells you which fault you have before anything is dismantled. Even without an analyser: vibration that rises smoothly with speed squared is unbalance, and vibration that appears suddenly at one particular speed is a resonance and is a different problem entirely.
আবশ্যক উপকরণ:
চৌম্বক ভিত্তিসহ ডায়াল ইন্ডিকেটরখাতাডেস্কটপ কম্পিউটার4
4
Correct by removing metal, or by adding it deliberately
Correct by removing metal, or by adding it deliberately
Drill or grind material away at the heavy spot, or add a weight opposite it. Removing is usually preferred where the rotor allows it, because an added weight is something that can come off at speed.
Whatever is added must be POSITIVELY retained — bolted, welded or fitted in a designed slot. A balance weight held on with adhesive that departs at 3000 rpm does not merely restore the original unbalance; it doubles it and becomes a projectile.
Then re-measure. Balancing is iterative: the first correction is an estimate, and two or three rounds are normal. Stopping after one because the vibration is better is how a rotor ends up permanently mediocre.
আবশ্যক উপকরণ:
সূক্ষ্ম দাঁড়িপাল্লাডায়াল ইন্ডিকেটরখাতাসম্পর্কিত ব্লুপ্রিন্ট
এই ব্লুপ্রিন্টগুলি জ্ঞান ভাগ করে — কৌশল, উপকরণ বা নীতি
CC0 পব্লিক ডোমেন
এই ব্লুপ্রিন্ট CC0-এর অধীনে প্রকাশিত। আপনি অনুমতি ছাড়াই যেকোনো উদ্দেশ্যে এটি অনুলিপি, পরিবর্তন, বিতরণ ও ব্যবহার করতে পারেন।
মেকারের ব্লুপ্রিন্টের মাধ্যমে পণ্য কিনে তাঁকে সমর্থন করুন, যেখানে তিনি আয় করেন মেকর কমীশন বিক্রেতাদের নির্ধারিত, অথবা এই ব্লুপ্রিন্টের একটি নতুন সংস্করণ তৈরি করে নিজের ব্লুপ্রিন্টে সংযোগ হিসেবে যুক্ত করে আয় ভাগ করুন।