Mechanical Engineering - Theory of machines - Discussion
Discussion Forum : Theory of machines - Section 1 (Q.No. 9)
9.
The factor which affects the critical speed of a shaft is
Discussion:
22 comments Page 1 of 3.
Ganeshr said:
4 years ago
Given ans is correct.
Critical or whirling or whipping speed is the speed at which the shaft tends to vibrate violently in the transverse direction.
The critical speed essentially depends on;
1. The eccentricity of the C.G of the rotating masses from the axis of rotation of the shaft.
2. Diameter of the disc,
3. Span (length) of the shaft, and.
4. Type of supports connections at their ends.
Critical or whirling or whipping speed is the speed at which the shaft tends to vibrate violently in the transverse direction.
The critical speed essentially depends on;
1. The eccentricity of the C.G of the rotating masses from the axis of rotation of the shaft.
2. Diameter of the disc,
3. Span (length) of the shaft, and.
4. Type of supports connections at their ends.
(1)
Amit soni said:
9 years ago
In this case mass stiffness- gravity and deflection are the effect the critical speed of the shaft because take critical speed is equal to natural frequency omega n.
Swagat said:
1 decade ago
The unbalanced mass of the rotating object causes deflection that will create resonant vibration at certain speeds, known as the critical speeds.
Pabitra said:
7 years ago
The answer will be A and B. w n is proportional to d^2/l^1.5.
So it does not depend upon eccentricity.
So it does not depend upon eccentricity.
Dheeraj said:
1 decade ago
The speed at which the deflection becomes infinity if eccentricity is away from the axis of rotation.
VVSS said:
9 years ago
Since critical speed depends on unbalanced mass about the axis of rotation. So option D is right.
JAYANT KOSHTA said:
9 years ago
Critical speed of shaft doesn't depend on eccentricity, hence, the given answer is wrong.
Santosh rajpoot said:
9 years ago
Critical speed of shaft does not depend on eccentricity, So, I think the answer is wrong.
Dheeraj singh mehta said:
10 years ago
Speed at which resonant vibrations occurs in shaft is called critical speed of shaft.
Prathmesh said:
3 years ago
The answer is only mass and stiffness span and diameter of rotor not eccentricity.
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