Lift-off performance in flexure pivot pad and hybrid bearings
| dc.contributor | Childs, Dara | |
| dc.creator | Mertz, David Hunter | |
| dc.date.accessioned | 2010-01-15T00:12:54Z | |
| dc.date.accessioned | 2010-01-16T01:25:14Z | |
| dc.date.accessioned | 2017-04-07T19:56:00Z | |
| dc.date.available | 2010-01-15T00:12:54Z | |
| dc.date.available | 2010-01-16T01:25:14Z | |
| dc.date.available | 2017-04-07T19:56:00Z | |
| dc.date.created | 2008-12 | |
| dc.date.issued | 2009-05-15 | |
| dc.description.abstract | Three flexure pivot pad bearings (FPBs) with different preloads are evaluated for use in high performance applications by comparing them to a hybrid hydrostatic bearing (HHB). One application of these bearings is in turbopumps for liquid rocket engines. To evaluate bearing performance, the lift-off speed of the shaft from the bearing surface is experimentally determined. Experimental data of lift-off are collected using a circuit running through the shaft and the designed bearing. Other methods for measuring liftoff speeds were attempted but did not yield consistent results. Water is used as a lubricant to simulate a low viscosity medium. In comparison to load-capacity-based predictions for FPBs, the experimental results showed lower lift-off speeds, higher load capacities, higher eccentricity ratios, and lower attitude angles. The bearings? predicted load capacity determined lift-off speed predictions, but the experimental results show no clear trend relating lift-off speed to load capacity. This was for a range of running speeds, with the design speed defined as the final speed in a particular test case. At 0.689 bar supply pressure and for a design speed of 3000 rpm, the HHB showed greater load capacities and lower eccentricities than the FPBs, but the FPBs had lower lift-off speeds and attitude angles. In fact, the FPBs in the load-between-pad orientation outperformed the HHB in the load-on-pocket orientation with lower lift-off speeds for the shaft weight-only case. An increased supply pressure lowered the lift-off speeds in the HHB tests. If the load in the bearing application remains relatively small, a FPB could be substituted for an HHB. | |
| dc.identifier.uri | http://hdl.handle.net/1969.1/ETD-TAMU-3197 | |
| dc.language.iso | en_US | |
| dc.subject | Lift off | |
| dc.subject | bearing | |
| dc.subject | lubrication | |
| dc.subject | hydrodynamic bearing | |
| dc.subject | hydrostatic bearing | |
| dc.subject | turbopump | |
| dc.title | Lift-off performance in flexure pivot pad and hybrid bearings | |
| dc.type | Book | |
| dc.type | Thesis |