Structure of Principal Axis and Failure Analysis of Cone Crusher

Cone crusher is a type of crushing machine that has very wide application, and its principal axis is a very important spare part. The principal axis of the cone crusher includes three types:

(1) Ladder type axis that is matched with the cone using cylindrical surface such as the China made, former Soviet Union and G type crusher, Simons standard type and 600 short-headed type crusher;

(2) Non-ladder type axis that is matched with the cone using cylindrical surface such as capstan crusher and Simons short-headed type crusher;

(3) Principal axis that is matched with the cone with cone surface such as AC bottom single cylinder hydraulic cone crusher, top single cylinder hydraulic cone crusher.

On the production site, many incidents happen due to the failure of the principal axis which is mainly because the working condition is very bad, and the principal suffers from heavy impact and workload, or because the matching installation of the principal and the cone is not appropriate, thus producing huge stress concentration or because of improper use. From the comparison of the structure combined with the analysis of the failure and stress situation of the principal axis, we can see that:

Due to different diameter and the section changing, the ladder type axis is easy to produce stress concentration, but the section of the cone type principal axis and the non-ladder type axis only match with the cone surface, and the changes only takes place once on the bottom. Secondly, as for the cone surface matching, the workers can properly reduce the magnitude interference of the matching surface and reduce the stress concentration, which is because during the crushing process, the crushing force will have constant wedge-caulking effect on the matching surface, but the precision degree of the axial installation and position of the cone surface matching is relatively weak. For this reason, when designing the principal axis, we should pay attention to the following points:

(1) Increase the knuckle of different sections and reduce the stress concentration;

(2) Adopt relatively big discharging chute;

(3) Adopt proper matching manner and magnitude interference;

(4) Ensure the processing precision of the principal axis.

To sum up, during the designing process of the structure of the principal axis, when it is possible, the workers should try to adopt whole hollow axis structure which will not only improve the strength and stiffness, but create conditions for the labyrinth sealing.