Study on the permutation of crusher's hammers based on position matrix and rotor balance

In order to explore the law of permutation of crusher′s hammers and meet the requirements for varying the permutation patterns of hammers to adapt to applications of crusher under different scenarios, the hammers position matrix concept is introduced to define the permutation pattern of hammers on a quantitative basis, based on the structural characteristics of crusher′s rotor. Then, the dynamic balance equation of the rotor fitted with hammers is derived by using the centrifugal force system simplification method, according to the needs for the main vector of the force system and the simplified main moment toward the geometric center of the rotor to become zero, and for the rotor to stay dynamically balanced. Following that, the different hammer arrangement patterns are classified and summarized together with the sharing of some experience in permutation of hammers. Study results show that the introduction of the concept of position matrix permits the transition of the traditional method of expressing arrangement pattern of hammers through language and graphs to an matrix expression that can be quantitatively calculated; with the use of the rotor′s dynamic balance equation, as long as the decomposition matrix and the force arm vector are calculated based on structural parameters of the rotor, the feasibility of any arrangement pattern of hammers on the rotor can be readily determined; and the arrangement pattern of hammers can be selected according to the required number of rows, circles and both geometric and functional characteristics. The study made in the paper not only serves as a guide for the design of crusher′s rotor, and making readjustment of hammers of the crusher working on site, but also provides a valuable reference for adding grouped counterweights in the case that the hammers are inconsistent in quality.