Research On Structure Optimization Of Aerostatic Thrust Bearing

Because of the current development of bearings and the physical characteristics of gas bearings,aerostatic thrust bearings are mostly used in high-precision and high-speed machine tools and instruments to make up for the corresponding high-precision and high-speed bearings.However,aerostatic thrust bearings have disadvantages such as low bearing capacity and poor stability.Therefore,this paper uses the finite element analysis software on fluid mechanics to calculate the static characteristics of the gas bearing by changing the parameters of the gas film thickness,the orifice and the equalizing chamber,and then through some methods of mathematical statistical analysis,the gas static The influence law of the static characteristics of the compression thrust bearing is summarized and summarized.Finally realize the understanding of the influence of various structures on the gas bearing,and optimize the structure of the aerostatic thrust bearing to explore the aerostatic thrust bearing with better bearing capacity or rigidity.In order to ensure the validity of the analysis process and the final data,this paper adopts the simple orifice throttling theory,equal quality of inlet and outlet flow,engineering calculation method and literature verification and other methods for comparative verification.Afterwards,through preliminary calculation and analysis,the effects of various structural parameters of single-row aerostatic thrust bearings on the static characteristics of this type of gas bearing are obtained.In the end,the bearing capacity will decrease as the thickness of the air film increases,and the stiffness will increase first and then decrease;when the orifice satisfies the simple orifice throttling,the depth of the orifice will affect the static state of the bearing.The characteristics have no effect,but the diameter of the orifice is one of the main factors affecting the bearing capacity and stiffness.Finally,through orthogonal experiment and analysis of variance,the parameter values of each structure of the single-row aerostatic thrust bearing under the condition of relatively optimal bearing capacity or stiffness are obtained.Through a large number of literature readings and summaries,there is no individual research on the structure of the three-row aerostatic thrust bearing,and the influence of its structure on the characteristics of the aerostatic thrust bearing is still unknown.Therefore,the influence of the position of the orifice hole row,the bearing width and the single orifice on the static characteristics of the three-row aerostatic thrust bearing is then explored.From the data results,the influence law of gas film thickness is the same as that of single-row holes and double-row holes,but the aerostatic thrust bearing with three rows of holes is compared with the aerostatic thrust bearing with single and double rows of holes.The advantage is that it can obtain greater bearing capacity and rigidity under a certain structure.Secondly,the outermost orifice of the three rows of holes is obtained through design orthogonal experiment and variance analysis,which has the greatest influence on the static characteristics of the gas bearing,then the innermost orifice,and finally the middle orifice.In order to determine the universality of the selection of the hole row position,the size of the three-row aerostatic thrust bearing and its influence on its characteristics are explored.The results show that the aerostatic thrust bearing is facing the orifice of this type of bearing.The choice of location has no effect.Finally,combining the research results of the orifice distribution,gas film thickness and format,we can get the relatively best orifice distribution corresponding to the gas film thickness in a certain range under various formats,which can be the three-row orifice gas static pressure The selection of the orifice hole position of each row of the thrust bearing provides a theoretical basis.In exploring the non-cylindrical orifice and pressure equalizing cavity,this paper proposes three types of orifices of spherical,arc surface and conical table type and two types of pressure equalizing cavity of four-leaf clover and cross structure.Through simulation calculations and results,it can be seen that the bearing capacity of the above three types of orifices is better than that of cylindrical orifices,but the influence on the stiffness needs to be combined with the thickness of the gas film,and the stiffness values of these three structures have certain values.Fluctuations.For the two structures of the pressure equalizing cavity,if the bearing capacity is used as the basis for selection,the cross-shaped equalizing cavity is better than the other two,followed by the cylindrical type,and finally the four-leaf clover type;if the bearing capacity is selected as the selection According to the model,the four-leaf clover pressure equalizing chamber is a good choice for low air film thickness.For high air film thickness,either a cross-type equalizing chamber or a cylindrical equalizing chamber can be used.