Loading...
Please wait, while we are loading the content...
Effects of bearing deadbands on bearing loads and rotor stability
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Copyright Year | 1984 |
| Description | A generic model of a turbopump, simplified to bring out these effects is examined. This model demonstrates that bearing deadbands which are of the same order of magnitude or larger than the center-of-mass offset of a rotor due to mass imbalances cause significantly different dynamic behavior than would be expected of a linear, dynamical system. This fundamentally nonlinear behavior yields altered stability characteristics and altered bearing loading tendencies. It is shown that side forces can enhance system stability in the small, i.e., as long as the mass imbalance does not exceed some thresholds value or as long as no large, impulsive disturbances cause the motion to depart significantly from the region of stability. Limit cycles are investigated in this report and techniques for determining these limit cycles are developed. These limit cycles are the major source of bearing loading and appear in both synchronous and nonsynchronous forms. The synchronous limit cycles are driven by rotor imbalances. The nonsynchronous limit cycles (also called subsynchronous whirls) are self-excited and are the sources of instability. |
| File Size | 8150890 |
| Page Count | 198 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19840011746 |
| Archival Resource Key | ark:/13960/t3cz8297z |
| Language | English |
| Publisher Date | 1984-01-20 |
| Access Restriction | Open |
| Subject Keyword | Mechanical Engineering Cycles Turbine Pumps Bearings Center of Mass Rotors Loads Forces Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
