The effects of friction in axial splines on rotor system stability

Journal Article · Thu Apr 01 00:00:00 EST 1993 · Journal of Engineering for Gas Turbines and Power; (United States)

DOI:https://doi.org/10.1115/1.2906705· OSTI ID:6414446

Artiles, A F ^[1]

---

1. Mechanical Technology Inc., Latham, NY (United States)

An in-depth parametric evaluation of the effects of Coulomb friction in an axial spline joint on the stability of the rotor-bearing system was conducted through time transient integration of the equations of motion. The effects of spin speed, friction coefficient, spline torque, external damping, imbalance, and side load as well as asymmetric bearing stiffnesses were investigated. A subnsynchrounous instability is present at the bending critical speed when the spin speed is above this critical. The limit cycle orbit is circular, proportional to the product of the friction coefficient and spline torque ([mu]T), inversely proportional to the external damping, and independent of spin speed. When imbalance is applied to the rotor, beating between the subsynchronous natural frequency and the synchronous (spin speed) frequency occurs. The subsynchronous component of the orbit is proportional to [mu]T, while the synchronous component is proportional to the imbalance. When a static side load is applied, the unstable node at the center of the orbitally stable limit cycle grows into an elliptical orbitally unstable limit cycle, separating stable from unstable regions of the phase plane. Below a threshold value of side load, the transient motion approaches one to two asymptotic solutions depending on the initial conditions: the larger stable limit cycle or a point at the center of the smaller unstable limit cycle. Beyond the threshold value of side load, the rotor-bearing is the stable and all motions decay to a point. Asymmetry in the bearing stiffnesses reduces the size of the subsynchronous whirl orbit.

• OSTI ID: 6414446
• Journal Information: Journal of Engineering for Gas Turbines and Power; (United States), Vol. 115:2; ISSN 0742-4795
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
TURBOMACHINERY
INTERNAL FRICTION
STABILITY
AVAILABILITY
BEARINGS
CRITICAL VELOCITY
MATHEMATICAL MODELS
MECHANICAL SHAFTS
MECHANICAL VIBRATIONS
PARAMETRIC ANALYSIS
PERFORMANCE
ROTORS
SYSTEMS ANALYSIS
EQUIPMENT
FRICTION
MACHINE PARTS
MACHINERY
SHAFTS
VELOCITY
200104* - Fossil-Fueled Power Plants- Components