Factors Affecting Bearing Vibration in Vibrating Screens (I)

Summary: In a vibrating screen, the working condition of bearings is generally very severe, which will cause the vibration of the bearing. And the vibration of the bearing may affect the screening effect and reduce the service life of the vibrating screen. ...

In a vibrating screen, the working condition of bearings is generally very severe, which will cause the vibration of the bearing. And the vibration of the bearing may affect the screening effect and reduce the service life of the vibrating screen. Many customers wonder how we can control and reduce the bearing vibration. Here, we firstly focus on the analysis of factors affecting bearing vibration in the vibrating screen.

Eccentric Vibration

At present, the vibration exciter in vibrating screen is generally eccentric shaft vibration exciter and box vibration exciter. The eccentric shaft vibration exciter is convenient to install and adjust, but its cost is relatively higher and the eccentricity cannot be adjusted. The box vibration exciter adopts a fan-shaped eccentric block whose relative position can be adjusted. In this case, it can achieve the adjustment of excited force and the adjustment of vibration amplitude.

While the vibration exciter works, the centrifugal force produced by the eccentric mass makes the eccentric shaft bend, which will lead to the relative deflection between the inner and outer rings of bearings. In this case, there will be vibration caused by eccentric. So the inertial force and inertia couple produced in the operation process will cause the dynamic reaction and vibration of bearings, breaking the stability of bearings and some other spare parts and causing high frequent vibration.

The vibrating system formed by bearings and eccentric system can be considered as single-degree-of-freedom system. The driving shaft and driven shaft of bearings both have some certain resonant frequency. If the vibration frequency is close to the resonant frequency, then there will be sympathetic vibration. Besides, since there is centrifugal inertial force because of eccentric, so there will be bending vibration produced.

The Geometric Accuracy Of Bearings

The strong excited force of vibrating screen makes the bearings bear large radial force, leading to the great vibration of vibrating screen. The higher the geometric accuracy of the bearings, the smaller the vibration will be. The percent ripple on the raceway, especially on the surface of the rolling elements, has the most important influence on vibration. The clearance of the rolling elements, cage, and rolling surfaces of the outer and inner rings, as well as their relative movement, will all cause the vibration of the bearings. The spin frequency of the rolling element is very high, so to reduce the vibration of the bearings, we first need to improve the surface machining accuracy of the rolling elements.

To be continued