Chao-Yang Tsai
The Journal of Mechanical Science and Technology, vol. 23, no. 5, pp.1383-1395, 2009

Abstract : A transfer matrix for shafts coupler with parallel misalignment (offset) was derived. The responses of a rotor system composed of flexible shafts, unbalanced disks, elastic supports and shafts coupler with misalignment were then investigated. Through the derivation, the boundary shears induced by a rotating shaft were first discovered to be coupled in two perpendicular directions. These coupling shears might reduce the first critical speed up to 50% in the free-free case. The studies showed that the shafts coupler altered the rotor’s critical speeds and the misalignment played as an external load resulting through the whole driven shaft. The combined effects of disk unbalance and shaft misalignment showed that the misalignment predominated the response in most of the rotation speeds, but the unbalance could become significant at high speed. The whirling orbits before and after the misalignment were illustrated as well, and numerical results showed that the two ends of the misalignment whirled asynchronously as the rotation fell into some regions.

Keyword : Misalignment; Shaft coupler; Transfer matrix method; Unbalance