Analysis And Improvement For Rotary Instability Of The ZR280C Rotary Drilling Rig

The large rotary drilling rig is a large mechanical equipment which is integrated with mechanical, electric, and hydraulic, it has developed rapidly since ten years ago in our country. Domestic manufacture produce rotary drilling rig mainly by imitating foreign existing modeling and the theoretical research is less, factory often increase the safety coefficient to ensure equipment running reliability in the structure field. This lead to the size is large and the work is not flexible. Using traditional calculation method is hard to get the analytical solution of the minimal reasonable structure stress after structure transformation for rotary instability phenomenon. The finite element method that is used to design the rotary drilling rig has some merits like high speed, high precision, and high reliability etc. At the same time the improved device can analysis the stress changes intuitively, which provides a very good method.This paper makes a detailed analysis about the H plane of rotary system, and uses the Pro-e and ansys software to simulate modeling on H plane, this paper also analysises deeply about the severe vibration problems of the rotating drill in the above car system. It pointes out the load of cyclical changes which would led to the bolts’ slap which connect the rotary system and below car system in the process of long-term using, the reason is that component stiffness is lacking. So we improve bolt form, increase the flange ring thickness and the middle plate thickness, increase the side plate thickness and increase the reinforcing rib to satisfy the need of strength. The simulation result demonstrates the feasibility of the scheme and achieves the objection. Meanwhile, these research methods and conclusions provide reference and theoretical for the later researcher and designer.