doi: 10.52899/24141437_2025_04_485
UDK: 621.822.2

Influence of Contact Shape of Mechanical Levelling Device Elements on Thrust Plain Bearing Operation of Rotodynamic Machine

Article language:
Citation Link: Gordeev NN, Smirnov AA, Malyavko EA. Influence of Contact Shape of Mechanical Levelling Device Elements on Thrust Plain Bearing Operation of Rotodynamic Machine. Transactions of the Saint Petersburg State Marine Technical University. 2025;4(4):485–496. DOI: 10.52899/24141437_2025_04_485 EDN: KCJPBB

Annotation

BACKGROUND: Different rigidities of a stator and a rotor of a rotodynamic machine causes an irregular load distribution between the segments of the thrust plain bearing. The increasing complexity of rotodynamic machine designs and their operating conditions contribute to this irregularity and reduce the bearing performance. One solution allowing to increase the performance of such bearings is mechanical alignment devices. Technical literature provides little information on the conditions of reciprocal travel of the elements of such devices and their influence on the bearing performance. In addition, there are barely any design recommendations. Thus, when developing new equipment, it is required to run heavy-duty tests of thrust bearings with alignment devices. AIM: To collect data on the reciprocal travel of elements, the impact of the contact surface shape on travels, and the types of resistance forces affecting the device performance and to develop recommendations on the use of contact surface shapes. METHODS: We selected a schematic model of the interaction of lower row levers of a mechanical alignment device with intermediate bodies, including spheres and supports installed in the housing. We have discussed nine models. The performance of all models was analyzed assuming that all parts are absolutely rigid. The calculations used various shapes and dimensions of the contact surfaces of lower row levers and housing supports. The ratios of the moment arms acting on the lever of the lower row of forces and travels in the contacts were adopted as efficiency criteria. RESULTS: When the lever of the lower row is turned, the arms of the moments of forces to the right and left of the support become unequal to each other. Sliding friction is present instead of rolling friction in the contacts of the levers with intermediate bodies. CONCLUSION: The support surface shape of the lower row lever has a significant effect on the alignment of forces across the segments. During design, it is required to select a support surface shape of the lower row lever and the housing support, which prevents the lever from rolling along the support. Keywords: thrust plain bearing; mechanical alignment device; contact; lever; lever arm; intermediate body; calculation

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