Rotor-Bearing Dynamics of Integrally Geared Turbomachinery
Abstract
This tutorial focuses on the rotordynamic characteristics of
integrally geared compressors and expanders. Although the
focus is for turbomachinery the topics discussed also apply to
industrial gearing. The topics covered include understanding the
influence of gear forces, thrust collars (hydrodynamic elements
that transmit load from pinion shaft to bull gear shaft), and thrust
bearings on the reaction loads of the pinion and bull gear
bearings. The various aspects that couple the pinion and bull
gear dynamics such as: 1) gear contact stiffness and 2) thrust
collar moment stiffness are examined to show the influence of
coupled pinion-bull gear rotordynamics. Torsional, lateral, and
axial rotordynamic behavior of geared systems is discussed
relative to different design standards: API617, API672, etc.
Various case studies are presented that show the vibration
characteristics for common field and shop problems. The case
studies used to illustrate the topics presented show the origin of
“step increases in vibration,” “sub-synchronous vibration
originating from aerodynamic excitation and bull gear harmonics
on the pinion shafting.
Description
TutorialsCollections
Citation
Wygant, Karl; Robertson, Chad; Li, Fang (2018). Rotor-Bearing Dynamics of Integrally Geared Turbomachinery. Turbomachinery Laboratory, Texas A&M Engineering Experiment Station. Available electronically from https : / /hdl .handle .net /1969 .1 /172447.