Research The Influence Of Clearance Seal On Performance Of Adjustable Hydraulic Torque Converte

General fluid machinery electricity consumption such as pumps and fans accounts for more than 30% of the country's total electricity consumption.However,the actual operating conditions of these devices often deviate from the design conditions,with low work efficiency and huge energy saving space.Variable speed regulation is an effective way to save energy.The hydraulic mechanical speed control system is an ideal speed control device for high-power machines because of its advantages of stepless speed regulation,large transmission power and long service life.The guide vane adjustable hydraulic torque converter is a key component of the hydraulic mechanical speed control system,since its system structure is complex and difficult to disassemble,the contact type seal is not convenient for maintenance,so the clearance seal with a long life is selected.Generally,the torque converter design calculation adopts a similar design method,regardless of the effect of the clearance seal,but it is particularly important to study the effect of the clearance seal on the flow field and performance of the torque converter when the leakage amount is large.The relationship between the amount of clearance leakage and the speed ratio is analyzed.Taking YDB880 adjustable hydraulic torque converter as reference model,the calculation model is established considering the inlet and outlet ports and four clearance.Through numerical calculation,firstly analyze the flow field in each impeller and clearance.It is found that the total leakage of the torque converter increases with the speed ratio decreasing.It provides a theoretical reference for the design of the hydraulic torque converter oil supply system.The influence of the labyrinth seal structure on the torque converter performance is analyzed.According to the parameters,establishing five sets of labyrinth seal calculation models.The sealing mechanism is verified by analyzing the flow field of the labyrinth seal.Then,studying the influence of the sealing groove structure on the sealing performance.By comparing the pressure difference between the inlet and outlet,it is confirmed that the larger width of sealing groove,the better the sealing effect,while the depth of sealing groove has little effect on sealing performance.On this basis,through improving the labyrinth seal structure,analyzing the influence of labyrinth seal structure on torque converter performance.The leakage is reduced at low speed ratios,but the overall efficiency is not significantly improved.The influence of the pump wheel turbine cavity clearance on the performance of the torque converter is studied.According to calculation,The axial force of the pump wheel gradually decreases with the increase of the speed ratio to 0.6,and increases in the opposite direction.However,the axial force of the turbine decreases with the increase of the speed ratio,and the direction is always negative.Through changing of the pump wheel turbine cavity clearance structure,studying the influence of the clearance seal on the torque converter performance.At a speed ratio of 0.9,the axial force of the pump wheel is the minimum when the width of the turbine disc clearance of the pump wheel is 7mm,and the axial force of the turbine wheel is the minimum when the width is 14 mm.The larger the gap width,the larger the torque converter leakage.However,as the friction loss of the disc is small,its efficiency is slightly improved.The influence of different vane opening on the performance and leakage of the torque converter is verified.It is found that the smaller the guide vane opening,the larger the leakage of the torque converter.Through the CFX dynamic mesh technology,researching the dynamic characteristics of the torque converter during the vane adjusting process.It is clarified that the adjustment torque of the guide wheel increases with the decrease of the guide vane opening.At the same time,the dynamic influence on the axial force during the decrease of the guide vane opening is studied,the axial force of the pump wheel increases while the axial force of the turbine decreases.