Imbalance
Imbalance in the propeller shaft causes vibration or noise, like in tires. The propeller shaft turns faster than tires by the gear ratio of the differential gear. Therefore, the frequency of Read more Propeller Shaft Vibration and Sounds
Vibration And Noise
Tire Uniformity Vibration and Sounds
Tire uniformity refers to uniformity of weight, dimensions and rigidity.
However, since uniformity of weight is ordinarily called “wheel balance” and uniformity of dimensions is called “run-out” uniformity Read more Tire Uniformity Vibration and Sounds
Run-out Vibration and Sounds
Since a tire is made by bonding together rubber, there is a in difference in the rubber thickness, the circumference of the tire is not a perfect circle.
Even if the tire is perfectly circular, if the Read more Run-out Vibration and Sounds
Wheel Balance Vibration and Sounds
Due to the weight unbalance of the rotating object, a centrifugal force is generated during rotation, which results in a vibrating force.
This vibrating force increases in proportion to the square of Read more Wheel Balance Vibration and Sounds
Tires Vibration and Sounds
The vibrating force caused by tires can be classified into two cases; the tire itself generates the vibrating force and uneveness on the paved road cause a vibrating force.
Tire itself generates vibrating Read more Tires Vibration and Sounds
Automotive Fan Noise
Fan noise produced by the cooling fans for the radiator, alternator, and others, become louder in proportion to their rpm.
The fan noise can be produced by fan blades cutting through the air, or by air Read more Automotive Fan Noise
Other Components of Engine Vibration and Sounds
Engine Mounts
Although engine mounts are relatively small, they are important in controlling NVH.
They link the vehicle body to the engine, the largest source of vibration. It is through these mounts Read more Other Components of Engine Vibration and Sounds
Engine Intake and Exhaust System Vibration and Sounds
Intake System
Intake noise includes the pulsating sound of the air taken in and the resonance sounds.
A pulsating sound has a relatively high frequency. It is determined by the air volume, shape of the Read more Engine Intake and Exhaust System Vibration and Sounds
Engine Imbalance due to Inertia
Vibrating forces due to inertia forces are caused by the crank mechanism and imbalance in the rotating object.
Among the inertia-caused vibrating forces, reciprocating mass can be balanced to a certain Read more Engine Imbalance due to Inertia
Torque Fluctuation due to Combustion
The vibrating force due to the combustion pressure causes torque fluctuation in the crankshaft, which is transmitted to the drive train.
It also acts upon the cylinder block as a reaction force and causes Read more Torque Fluctuation due to Combustion