What are the causes of gear vibration faults?

Wheel drive is the most commonly used transmission method in mechanical equipment, widely used in various industries. As a gear device for transmitting motion and power, it plays an important role in almost any large-scale equipment.

1. A pair of gears that mesh with each other will experience periodic changes in the elastic stiffness of their teeth. The change in the elastic stiffness of the gear teeth causes the bending amount of the teeth to also change, resulting in collisions between the gear teeth when entering and exiting the meshing area, causing the gear to produce vibration and noise with a frequency equal to the meshing frequency.

2. The transient free vibration generated by the continuous transmission of external power to gears often triggers natural frequency vibration of the casing when the fault is very serious.

Gearbox vibration fault detection
3. Tooth surface fatigue mainly includes tooth surface pitting and peeling. The main cause of pitting corrosion is micro fatigue cracks caused by alternating stress on the working surface. After lubricating oil enters the crack, the inlet may be closed first and then squeezed during the meshing process. The lubricating oil inside the micro fatigue crack expands under high pressure, resulting in small pieces of metal falling off the tooth surface, leaving a small pit and forming pitting corrosion.

4. When there are defects such as eccentricity, pitch error, and tooth profile error in the gear, the gear cannot operate smoothly, or accelerate or decelerate, causing collisions between the gear teeth and the tooth surface to be subjected to significant dynamic additional loads, resulting in gear vibration.

5. When the gear pair transmits motion through meshing, the force of the driving wheel and the reaction force of the driven wheel both act on the opposite tooth through the contact point. The most dangerous situation is that the contact point is located at the top of the tooth at a certain moment. At this time, the tooth is like a cantilever beam, and the bending stress generated at the tooth root after being loaded is the maximum. If suddenly overloaded or impacted, it is easy to cause overload fracture at the tooth root.

6. When the gear rotation shaft is composed of two shafts connected by a coupling, if the centerlines of the two shafts are offset, angled, or staggered with different shafts, low-frequency and high-frequency meshing frequencies and sideband wave vibrations will occur.