Study On Sealing Performance Of High Speed Hydraulic Rotary Joint

Rotary joint is a connecter that transfers a fluid medium from a fixed pipe to a rotating or swinging pipe to transport a fluid medium.Its performance should not only ensure the continuous flow of fluid from fixed pipeline to rotating or swinging pipeline,but also prevent its fluid medium from being connected in series and leaking inside the pipeline and external pollution.Rotary joint can transfer and seal working medium under high pressure and high speed condition,and has been widely used in many engineering fields.Therefore,the sealing performance of rotary joint at high rotaring speed is critical to the rotary joint and overall performance of equipment.The seal form of high-speed hydraulic rotary joint is clearance seal.After reading relevant literatures at home and abroad,the calculation formulas of the clearance seal under the conditions of laminar flow and turbulent flow,wall static and wall rotation,as well as the corresponding hole and shaft concentric,hole and shaft eccentric,and shaft tilt are derived.Then using computational fluid dynamics(CFD)technology,the ICEM CFD software is used to mesh the internal flow field of the rotating joint,and the computational fluid dynamics software Fluent 17.0 is used to simulate the flow field.The internal flow field of the rotary joint at different speeds is analyzed.The distribution form and the leakage law are obtained.The distribution law of the internal flow field and the influence of the flow field distribution on the leakage amount are obtained under different speed ranges.Finally,through simulation analysis,the effects of different sealing parameters of the 50 T fan air volume adjustment servo cylinder on the leakage amount,including the sealing length,the sealing gap amount,the sealing diameter,the mandrel eccentricity,the temperature,the opening of the pressure equalizing groove,etc.,are studied.The simulation data is used to analyze the performance parameters affecting the leakage amount,and the causes and laws of the leakage are obtained.At the same time,the optimal values of each sealing parameter are determined according to the simulation data and the actual working conditions.