1. Pumping unit shaking
2. Displacement between parts
3. Frame or horse head vibration, motor emitting uneven noise
4. Crank pin loose in crank hole or periodic noise due to axial displacement
②
④ Tighten lock nut, implement anti-loosening measures
5. Connecting rod rubbing against crank or flat block
6. Broken connection between crank and gearbox crank shaft, crank violently jumping
② Replace with new key, install in a new keyway 90 degree from the old one
7. Bearing or bearing housing displacement
8. U-bolt bending
9. Walking beam axial displacement
Cause: Loose U-bolts
10. Brake failure or automatic braking
11. Knocking sound in gearbox
12. Severe pitting wear or scoring of gearbox gears under good lubrication conditions
13. Uneven wire rope tension in hanger
14. Loose connection between hanger and polished rod
15. Belt loosening causing belt slippage
