本文選題：回轉臺 + 動靜壓軸承�。� 參考：《山東大學》2017年碩士論文

【摘要】：回轉工作臺是大型、重型數(shù)控加工設備的主要部件,其性能優(yōu)劣影響著設備的加工質量和運行效率。而在轉臺中,推力軸承是其關鍵部件。在大型回轉臺中,采用大型重載推力滾珠軸承不僅制造困難、成本高而且磨損嚴重,目前裝備制造業(yè)中主要采用靜壓推力軸承。動靜壓軸承是在綜合動壓軸承和靜壓軸承的優(yōu)點后而開發(fā)出來的的新型軸承,具有啟動力矩小,油膜剛性高,承載能力強和性能可靠等優(yōu)點。當動靜壓軸承工作在一定轉速時,可以降低供油壓力,從而顯著地減小供油系統(tǒng)的功耗。本文對一種新型動靜壓轉臺的性能進行了研究,主要對動靜壓轉臺的壓力分布建模進行了計算,研究了工作條件和結構參數(shù)對靜態(tài)、動態(tài)特性的影響,并將采集得的實驗數(shù)據(jù)和計算結果進行了相應的對比,具體工作內容如下:(1)對動靜壓轉臺的油腔結構進行了介紹,建立螺旋油楔的油膜厚度方程,綜合考慮雷諾方程和流量連續(xù)性方程,采用有限元法對動壓螺旋油楔區(qū)域的油膜壓力進行了計算。與相關文獻的計算結果進行了對比,驗證了所編制的MATLAB有限元程序的正確性與可靠性。聯(lián)立求解雷諾方程與流量連續(xù)性方程,建立了轉臺靜態(tài)特性計算模型。對回轉臺承載力、摩擦力矩和流量等靜態(tài)特性進行了計算。(2)分析了固定負載條件下轉速與供油壓力分別變化對轉臺靜態(tài)特性的影響,研究槽深、螺旋角、槽數(shù)、槽寬比、槽徑比和螺旋油楔徑向長度比等結構參數(shù)對轉臺靜態(tài)特性的影響規(guī)律,綜合考慮總承載力和動壓比對結構參數(shù)的選取范圍進行了推薦�？紤]油膜厚度較小時螺旋油楔存在的供油不足的情況,提出了一種結構改進的方法,研究結果表明,改進后的結構可以解決一定工作條件下螺旋油楔供油不足的問題,并能顯著提高承載力,同時可以降低靜壓油腔封油面的加工精度。(3)考慮擠壓效應對穩(wěn)態(tài)雷諾方程和流量平衡方程進行了修正,采用差分法對轉臺剛度系數(shù)和阻尼系數(shù)進行了計算,分析工作條件和結構參數(shù)對動態(tài)特性的影響,為轉臺油腔結構參數(shù)的優(yōu)化提供了參考。(4)介紹了實驗系統(tǒng)的構成和傳感器的布置,對渦流傳感器的實際初始安裝間隙進行了標定。對于采集的實驗數(shù)據(jù)采用理想低通濾波器進行了處理,并和計算結果進行了對比,結果表明計算結果和實驗數(shù)據(jù)吻合較好,計算方法較為可靠。本文完成了動靜壓轉臺的壓力分布建模與靜動態(tài)特性分析,為以后的結構優(yōu)化與運動平穩(wěn)性分析等進一步的研究打下理論基礎。
[Abstract]:Rotary table is the main component of large and heavy NC machining equipment, and its performance affects the machining quality and operation efficiency of the equipment. In the turntable, thrust bearing is the key component. In the large scale rotary table, it is difficult to manufacture large heavy load thrust ball bearings, high cost and serious wear. At present, hydrostatic thrust bearings are mainly used in the equipment manufacturing industry. The hydrostatic bearing is a new type bearing which is developed after combining the advantages of hydrodynamic bearing and static bearing. It has the advantages of small starting moment, high oil film rigidity, strong bearing capacity and reliable performance. When the dynamic and static bearing is working at a certain speed, the fuel supply pressure can be reduced, and the power consumption of the fuel supply system can be significantly reduced. In this paper, the performance of a new type of dynamic and static pressure turntable is studied. The pressure distribution of the table is calculated, and the influence of working conditions and structural parameters on the static and dynamic characteristics is studied. The experimental data are compared with the calculated results. The main contents are as follows: (1) the structure of the oil chamber is introduced, and the oil film thickness equation of the spiral oil wedge is established. Considering Reynolds equation and flow continuity equation, the oil film pressure in the hydrodynamic spiral wedge region is calculated by finite element method. The validity and reliability of the MATLAB finite element program are verified by comparing with the calculation results of related literatures. The static characteristic calculation model of turntable is established by solving Reynolds equation and flow continuity equation simultaneously. The static characteristics such as bearing capacity, friction moment and flow rate of rotary table are calculated. (2) the influence of the change of rotational speed and oil supply pressure on the static characteristics of turntable under fixed load is analyzed, and the groove depth, spiral angle, slot number and slot width ratio are studied. The influence of structural parameters such as groove diameter ratio and radial length ratio of spiral oil wedge on the static characteristics of turntable is studied. The selection range of structural parameters is recommended considering the total bearing capacity and dynamic pressure ratio. Considering the shortage of oil supply in spiral wedge with small thickness of oil film, a method of structure improvement is proposed. The results show that the improved structure can solve the problem of insufficient oil supply in spiral wedge under certain working conditions. It can improve the bearing capacity and reduce the machining accuracy of the seal surface of the hydrostatic oil chamber. (3) considering the extrusion effect, the steady state Reynolds equation and the flow equilibrium equation are modified. The stiffness coefficient and damping coefficient of turntable are calculated by difference method, and the influence of working conditions and structural parameters on dynamic characteristics is analyzed. It provides a reference for the optimization of the structural parameters of the turntable oil chamber. (4) the structure of the experimental system and the arrangement of the sensor are introduced, and the actual initial installation clearance of the eddy current sensor is calibrated. The collected experimental data are processed by the ideal low-pass filter and compared with the calculated results. The results show that the calculated results are in good agreement with the experimental data and the calculation method is more reliable. In this paper, the pressure distribution modeling and static and dynamic characteristics analysis of the static and static pressure turntable are completed, which lays a theoretical foundation for the further research on structure optimization and motion stability analysis.
【學位授予單位】：山東大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG659

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相關碩士學位論文 前1條

1 劉云鵬;新型動靜壓轉臺靜動態(tài)特性分析[D];山東大學;2017年

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本文編號：2104079