Mechanical vibration — Vibration of rotating machinery equipped with active magnetic bearings — Part 5: Touch-down bearings

This document gives guidelines for identifying:

a) The typical architectures of touch-down bearing systems to show which components are likely to comprise such systems and which functions these components provide;

NOTE Touch-down bearings are also known as “backup bearings”, “auxiliary bearings”, “catcher bearings” or “landing bearings”. Within this document, the term “touch-down bearings” is used exclusively as defined in ISO 14839 1.

b) The functional requirements for touch-down bearing systems so that clear performance targets can be set;

c) Elements to be considered in the design of the dynamic system such that rotordynamic performance can be optimized, both for touch-down bearings and active magnetic bearings (AMBs);

d) The environmental factors that have significant impact on touch-down bearing system performance allowing optimization of overall machine design;

e) The AMB operational conditions that can give rise to contact within the touch-down bearing system so that such events can be considered as part of an overall machine design. It also considers failure modes within the AMB system that can give rise to a contact event. This ensures that the specification of the t