Research On Numerical Simulation And Experiment Of Labyrinth Seal

Transmission as important components, it has been widely applied to various field. And most of the gear box’s sealing structure use self-tightening oil seal. Because high-speed rotating results in run-out errors, the oil seal lip of the oil seal wears seriously in using process. It’s easy for the leakage of lubricants to appear. And this phenomenon will lead to the leakage of lubricants and being polluted by impurity. It will damage the bearings and gear because of the oil’s lack or the decrease of lubricants’ performance. In order to work normally, the self-tightening oil seal often needs changing and it’s necessary to shut down while changing so that it costs manpower and material resources and it’s complex. In order to keep working efficiently, it’s necessary to improve the seal structure. So non-contact labyrinth seal, which can decrease wear and operation and maintenance costs, is used. Therefore, non-contact labyrinth seals apply to the special occasions that should not be using the tight oil seal. However, if the rotor doesn’t match well with the stationary part in labyrinth seal, it will damage sealing elements and increase leakage even more serious losses. So it’s very important to study the mechanism of labyrinth seal thoroughly and design reasonable structure of labyrinth seal for decreasing leakage.The object of study is labyrinth seal in gearbox of wheel-side reducer and this thesis introduces and uses four calculating methods including Egli, Kearton, Vermes and an iterative algorithm in order to calculate the leakage of labyrinth seal.What’s more, it uses numerical analysis to analyze the leakage of labyrinth seal. By using flow analysis in analyzing labyrinth seal, it builds three-dimensional model of staggered typical labyrinth channels so that it’s convenient to consider fluid circumferential turbulence. ANSYS is used to build model, divide mesh and set boundary condition. CED-Fluent is used to study flow and leakage of labyrinth cavities. Using simple variable method to do numerical modeling can obtain the conclusion that how temperature, import and export pressure ratio, lubricant viscosity, rotation rate and labyrinth geometry size influence the leakage of labyrinth seal.The research shows that the leakage will increase with the decrease of lubricant viscosity, and it’s proportional to pressure ratio, being influenced little by rotation rate. The leakage will increase with the increase of clearance. Increasing the depth of the cavity within limits can effectively decrease the leakage of labyrinth seal. While along with the increase of the depth of the cavity within limits, the leakage isn’t nearly affected, increasing the depth or breadth will increase the leakage, and there is a best depth-to-width ratio.What’s more, in order to verify the accuracy of numerical analysis, one test stand which can simulate wheel-side reducer working normally is built. Test verification of labyrinth seal at the conditions of different speeds、clearance of sealing tooth and the highly of lubricating oil. Computing and actual measuring the leakage in different conditions combined theory and experiment to verify the feasibility of the numerical computation method and the rationality of the design of the labyrinth seal structure, provided some academic bases and references for the design of the labyrinth seal.