When the vane seal slides on the contact surface of the end seal of a hydraulic rotary vane actuator (RVA), this surface undergoes elastic deformation, and even seal failure may occur through the combined action of the normal contact pressure and tangential force. In this article, a model of the elastic deformation of the contact surface of the end seal is established, and factors influencing elastic deformation are studied. The results show that deformation of the contact surface of the end seal in the x– and y–direction increases with an increase in the pre-tightening force. However, deformation of the contact surface of the end seal in the x– and y–direction is reduced as the vane-seal radius and the end seal elastic modulus increase.

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Background: To retrospectively analyze the pulmonary computed tomography (CT) characteristics and dynamic changes in the lungs of cured coronavirus disease 2019 (COVID-19) patients at discharge and reexamination.Methods: A total of 155 cured COVID-19 patients admitted to designated hospitals in Yunnan Province, China, from February 1, 2020, to March 20, 2020, were included. All patients underwent pulmonary CT at discharge and at 2 weeks after discharge (during reexamination at hospital). A retrospective analysis was performed using these two pulmonary CT scans of the cured patients to observe changes in the number, distribution, morphology, and density of lesions.Results: At discharge, the lung CT images of 15 cured patients showed no obvious lesions, while those of the remaining 140 patients showed different degrees of residual lesions. Patients with moderate disease mostly had multiple pulmonary lesions, mainly in the lower lobes of both lungs. At reexamination, the lung lesions in the patients with moderate disease had significantly improved (P<0.05), and the lung lesions in the patients with severe disease had partially improved, especially in patients with multi-lobe involvement (χ 2 =3.956, P<0.05). At reexamination, the lung lesions of patients with severe disease did not show significant changes (P>0.05). Conclusions:The pulmonary CT manifestations of cured COVID-19 patients had certain characteristics and variation patterns, providing a reference for the clinical evaluation of treatment efficacy and prognosis of patients.

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Abstract. Vane seal -hydraulic cylinder inner wall (rotor outer circle) friction pair is studied as object of this paper. The contact pressure mathematical model of vane seal was established by using the generalized Hooke's law, and the distribution of pressure on the contact surface was obtained. Based on the transient average Reynolds equation and the G-W micro-bulge contact model, the hydrodynamic lubrication model of the surface of the hydraulic rotary vane actuators with the surface topography was established. Under the condition of the contact pressure of the vane, the lubrication model was carried out by inverse solution method and the distribution of oil film thickness were obtained. The influence of the surface morphology on the lubrication seal of the vane was analyzed by the known curve of the surface performance parameters of the vane seal surface, which provides a theoretical basis for the sealing of the hydraulic rotary vane actuators.