What causes vibration in drive shaft?

What causes vibration in drive shaft?

Vibration in a driveshaft can be caused by many conditions. One of the most common cause of driveline vibration are worn U-joints or slip splines, out-of-balance components, yokes out of phase or misaligned angles, approaching critical speed range, and yoke ears that are not concentric with the splines.

What is phasing a drive shaft?

Phasing is the process of aligning the universal joint yokes on both ends of the drive shaft (or double u-joint)in a parallel fashion. If the joints are not properly phased, they will operate at varying speeds throughout each revolution which can cause second-order vibrations.

What holds a driveshaft in place?

Connecting the two sections of the driveshaft is a center support bearing, which is a “U” shaped metal bracket with a solid-rubber machined bearing on the inside. The bearing is designed to keep both parts of the driveshaft solid in order to reduce harmonic vibration as the vehicle accelerates.

What happens when a driveshaft is out of phase?

If the driveline is left out of phase even the small unfelt oscillations and unbalances will wear on the driveline components and eventually lead to failure. U-joints, transmission output seals, and differential seals will all be placed under the stress of the driveshaft moving up and down.

How does a driveshaft get out of balance?

Something off the road could hit the driveshaft, causing it to be out of balance. The u-joints could have lost their grease, causing metal-on-metal grinding, which will in turn make the driveshaft vibrate. A weight on the driveshaft could have fallen off, leaving the driveshaft unbalanced.

What does driveshaft vibration feel like?

Signs of a bad driveshaft/drivetrain A common symptom of a failing driveshaft is an intense shaking coming from underneath the vehicle. Worn out u-joints or bushings can cause the driveshaft to vibrate. Vibrations caused by tire balance issues are speed sensitive while driveshaft vibrations aren’t.

When do vibration levels in a gearbox increase?

A case study of a gearbox. Late last fall, routine monitoring of a gearbox showed an increase in overall vibration levels, which was not apparent in the spectra. If the gearbox failed during the winter, the process plant would not have been able to start up again until spring.

How is gear ratio related to speed of output shaft?

Speed of Output Shaft = Gear Ratio / Speed of input Shaft Gear Reduction As shown above, if the number of gears on the output shaft is greater than gears on the input shaft.

How to calculate the gear ratio of a train?

Divide the number of teeth on each “driven” gear by the number of teeth on the “drive” gear for each interlocking set of gears to calculate the intermediate gear ratios. In our example, the intermediate gear ratios are 20/7 = 2.9 and 30/20 = 1.5. Note that neither of these are equal to the gear ratio for the entire train, 4.3.

How is resonance analysis done in a gearbox?

Resonance analysis takes the natural frequencies and vibrations in the gearbox and analyzes them. Resonance tests can be conducted with a coast-down curve, impact tests, run-ups, and measurements of bending lines on the shafts.