The uniaxial circular vibrating screen can be divided into simple vibrating screen and self - fixed center vibrating screen.
The feature of the simple vibrating screen is that the shaft axis of exciter is in a straight line with the center of the pulley, therefore, both the pulley and the exciter shaft are involved in the vibration, so that the screening machine usually works in the state of far beyond resonance. The advantages of simple vibrating screen are simple structure and easy manufacture. The disadvantage is that it vibrates with the pulley and the straining box. No matter the motor is installed at any angle, the cycle change of belt transmission center distance cannot be avoided, thus causing the repeated body length and shortening of the triangle belt, affecting its service life. In order to reduce the impact on the life of the belt, the triangle belt must be longer.
When the screen machine operates, the triangle belt pulley of the self- fixed center vibrating screen does not vibrate with the straining box. The advantages of screening machine is the long life of transmission belt and stable work state.

The structural characteristics of the exciter of the inclined screen
1.The unbalanced weight block that produces the inertial force is mounted on a shaft of great rigidity, so roller bearings with great bearing capacity can be used.
2.The use of roller bearings simplifies the lubrication system because other bearings require expensive circulating lubricants, while roller bearings are simply lubricated by lubrication holes or concentrators, or by grease, which is simple and inexpensive.
3.The exciter is removable and when the bearing is damaged, the whole exciter can be removed and replaced.
The existing problems of circular vibrating screen exciter
Bearing damage. There are a lot of vibrating machines in industrial production, and inertia exciter is widely used in these vibrating machines. The reason is that the structure of the inertial exciter is simple and easy to manufacture, installation and maintenance are convenient, and can get a larger vibration force, so the object being excited can get a larger vibration acceleration. However, there are also some disadvantages of the inertial exciter. For example, it is not easy to automatically adjust the excitation force and frequency. But the more important disadvantage is that the bearing in the exciter is inevitably subject to a large dynamic load, which tends to increase the temperature of the bearing and damage the lubrication conditions, greatly shortens the service life of the bearing, and also affects the service life of other components besides the exciter.
Motor damage. The main form of motor damage is the jam problem of bearing. The main reasons for the failure are heavy load, heavy dust, high environment temperature. After the bearing is jammed, under the action of the traction force of the excitation motor and the inertia force of the eccentric block, the bearing ball and ball rack are twisted, crushed and damaged. When it is serious, the screw connecting the vibration motor and the vibration screen is cut off, and the vibration exciter is separated from the vibration screen. The jam problem of bearing is the main cause of vibration motor damage, it is because the working environment of the vibration motor is poor, the vibration frequency is high, the heat generated by friction between the movement of journal and the bearing can not be released in time.
At present, the exciter with eccentric block structure is widely used on the exciter, which has the advantages of reasonable structure, light weight, convenient construction and assembly. However, there is much to be improved.
1.The construction and assembly process of the exciter is complicated, which affects the assembly quality.
2.Due to the specific assembly process, the exciter cannot be completely replaced, and the position accuracy is difficult to ensure that the user cannot store all finished shaker, which brings inconvenience to equipment maintenance.
3.The connection between the bearing seat of the circular vibrating screen and the side plate needs to be improved, the connection is generally inconvenient to maintain. During the work, because the bolt looseness is not found in time, the vibration exciter bolt is cut, causing the phenomenon of vibration exciter damage, affecting the production.