20.500.12556/RUL-182906 Influence of spool impact on preloaded threaded plugs in hydraulic valves Preloaded threaded plugs that limit axial movement of spools in hydraulic valves are repeatedly loaded by spool impacts, which affects their fatigue strength. For proper dimensioning of these plugs, their loadings must be known. The aims of the study are to: (a) determine the spool impact force (▫$F_{impact}$▫) on the plug head, (b) determine its influence on the force in the plug neck (FIPN) and (c) give design recommendations and practical considerations for plug–valve connections. Modified versions of the plugs were produced and equipped with strain gauges. The plugs were tightened into valves and loaded with spool impacts at three different pilot pressures. Meanwhile, ▫$F_{impact}$▫, FIPN, pilot pressure, and spool displacement were measured. As the FIPN was measured in the modified plug–valve connections, which had different stiffnesses from the original connections, the FIPN in the original plug–valve connections was calculated by considering the stiffness ratios of the original connections obtained from finite element analyses. The results show that the spool impact force and the resulting additional FIPN increase linearly with pilot pressure. To achieve smaller amplitudes of the FIPN and, consequently, higher fatigue strength, the tensioned parts of the plugs should have lower stiffness and the clamping parts higher stiffness. pre-tightened connection hydraulic valves piston strike clamping force strain gauges prestressed fastener prednapete vijačne zveze hidravlični ventili udar bata sila tesnjenja merilni lističi prednapeti vijaki true false true Angleški jezik Slovenski jezik Članek v reviji 2026-05-28 08:09:49 2026-05-28 08:09:55 2026-05-29 04:36:57 0000-00-00 00:00:00 2026 0 0 19 str. issue 11, art. 5366 Vol. 16 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 620.178:621.88.082 2076-3417 10.3390/app16115366 279586819 Hladnik...Influence_of_spool....pdf Hladnik...Influence_of_spool....pdf 1 46E41D05E1FBF1E5F8783D5A54DFF631 0f29ce0774b6e2071b9214138a0e0a88701f0fc41eb597b5fbc0c073a8e2e858 ba2869bf-5a5b-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=234558 https://www.mdpi.com/2076-3417/16/11/5366 1 8210d440-5a5b-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=234557 Fakulteta za strojništvo 0 0 0