ISO/AWI 14839-6

Mechanical vibration — Vibration of rotating machinery equipped with active magnetic bearings — Part 6: Load capacity requirements, predictions and validation

Scope

The scope of the standard is to clarify the interpretation of load capacity in Active Magnetic Bearing (AMB) systems. With traditional passive bearings of the rolling element or fluid lubricated journal types, load capacity is the maximum load or force that the bearing can experience in a machine before permanent deformation or fatigue failure. In contrast, an AMB operates with a magnetic gap and may be designed to have a maximum load capacity for a particular application. An AMB has the added feature of being controllable, hence, to be able to apply a spectrum of controllable forces over a prescribed frequency range. The scope of this document covers the following attributes of an AMB:
• The static force capacity when the journal is statically centered with zero offset.
• The static force capacity when the journal is at its maximum offset position.
• The dynamic force capacity as a function of frequency and force direction.
• The peak transient load capacity over a limited time period.
• Limitations of force capacity arising from operating temperatures and available power amplifier capacities of voltage and/or current.
• The operational conditions of a machine that give rise to loss of stability margin, or journal/rotor contact with touch-down bearings, or variation of the journal/rotor levitation position.