Lift-off performance in flexure pivot pad and hybrid bearings /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2010]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| 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. |
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| Item Description: | "Major Subject: Mechanical Engineering" Title from author supplied metadata (automated record created 2010-03-12 12:08:51). Electronic resource. |
| Physical Description: | 1 online resource. |
| Bibliography: | Includes bibliographical references. |