Full Annular Rub in Mechanical Seals, Part II: Analytical Study

DONALD E. BENTLY ； PAUL GOLDMAN ； JOHN J. YU

《International Journal of Rotating Machinery》 2002卷 (2002/12) Pp. 329-336

https://doi.org/10.1155/S1023621X02000313

摘要

This paper outlines the analytical study of the rotor lateral response under conditions of contact between the rotor and mechanical seal. The seal is modeled as an added stiffness and dry friction force, applied to the rotor during contact. The rotor is assumed sliding in the mechanical seal circular clearance due to unbalance force. The resulting equations allow for rotor synchronous circular response with stable and unstable branches of the amplitude-frequency characteristics. It is typical for jump phenomena. Nonlinear equations of motion are investigated for the stability of this particular solution. Root locus plots are utilized. Instability zones are determined to lead to the self-excited limit cycle reverse precession known as ＂dry whip＂. Destabilizing factors are rotor-seal dry friction coefficient and seal stiffness. A stability study is also performed for the self-excited limit cycle reverse precession. The conditions for the rotor-mechanical seal parameters are derived to avoid ＂dry whip＂ under any amount of unbalance.

關鍵字

Full annular rubs ； Synchronous response ； Stability ； Self-excited vibration ； Reverse precession