This master’s thesis addresses the analysis of sealing between the piston and the housing in an axial piston pump used for oil extraction, with the aim of improving sealing performance. Undesired mixing of lubricating oil and the crude oil mixture occurs within the pump. The methodology includes a literature overview, the design and manufacture of a dedicated test rig, and dynamic testing of various seals, at various surface roughness levels, and at various fluid viscosities under oil/air and oil/water sealing conditions. The initial results show that during oil/air testing, oil leakage is practically negligible, whereas significantly higher leakage occurs during oil/water testing; increased surface roughness and viscosity were found to increase medium transfer. The findings indicate that the transfer most likely occurs through microscopic pores in the piston material. It was established that PTFE seals provide effective water sealing, while PU seals perform well in oil sealing applications, and that the use of multi-stage sealing or the implementation of an intermediate air pockets significantly improves sealing performance. Practical experiments conducted on the dedicated test rig demonstrated that the selected combination of PTFE seals substantially reduces oil leakage across the sealing system and significantly limits water intrusion into the oil chamber, which was the primary objective of this study. Potential design modifications of the axial piston pump housing are also proposed to enable the implementation of the recommended sealing configurations.
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