The causes of slurry pump vibration are highly complex and usually result from a combination of multiple factors. These can be summarized into the following major categories:

Rotor Imbalance:
Causes: This is the most common cause of mechanical vibration. Due to uneven wear of the impeller (a typical issue in slurry pumps), foreign material buildup, or manufacturing defects, the mass center of the rotor does not align with its rotational center.
Manifestation: The vibration frequency matches the rotational frequency (1X), and the amplitude increases with higher rotational speeds.

Misalignment:
Causes: The centerlines of the pump shaft and the motor shaft do not coincide (resulting from parallel offset, angular misalignment, or both).
Manifestation: Typically produces high axial vibration along with radial vibration at twice the rotational frequency (2X).

Bearing Damage:
Causes: Bearings develop issues such as pitting, wear, or excessive clearance due to poor lubrication, improper installation, fatigue, or contamination.
Manifestation: Increased vibration noise and possible high-frequency impact signals (related to the bearing component passing frequencies).

Shaft Bending or Wear:
Causes: The pump shaft becomes bent or worn due to long-term uneven loading, thermal stress, or friction with sealing components, directly leading to rotational imbalance.

Foundation and Anchor Bolt Looseness:
Causes: Insufficient rigidity of the pump foundation, improper grouting, or loose anchor bolts can amplify and transmit vibrations.

Impeller Rubbing Against Liner/Pump Casing:
Causes: Contact and friction between the rotating impeller and the stationary liner or pump casing due to unbalanced axial forces, excessive bearing clearance, or improper assembly clearances.
Manifestation: Produces a harsh rubbing sound and irregular vibrations.

Coupling Issues:
Causes: Wear, looseness, or inherent imbalance in the coupling.