| Lubricating oil is a kind of high value-added products refined from petroleum, which is widely used in various mechanical equipments due to its good performance of lubrication, cooling, anti rust and sealing. Some of the underused lubricating oil or used oil not yet reaching the replacing target is discarded or discharged randomly, which has not only caused serious pollution to natural environment like rivers and soil, but also caused huge waste of oil resources. To save oil resources from the aspects of economy and energy, it is in urgent need for people to begin the relative study of waste oil on the regeneration, purification and the efficient use of the waste oil, especially the research on technologies of waste-oil regeneration and purification equipments of oil-filter, which will bring great economic, social and ecological benefits.Vacuum oil-filter is a kind of typical waste oil purification equipment, which can wipe off the water, gas and other purification of waste oil under the condition of vacuum environment provided by vacuum pump. Since the scroll disks are the central components of the scroll-type vacuum pump of vacuum oil-filter, its properties determine the performance of vacuum pump directly, and thus, affect the performance of vacuum oil-filter indirectly. In order to improve the efficiency of vacuum oil-filter and reduce its energy consumption, more fundamental researches are needed to study and improve the characteristics of scroll disks, to optimize the structure of scroll disks, so as to improve the working efficiency of scroll vacuum pump, and in the end, to enhance the performance of vacuum oil-filters.Based on the structure characteristics and working principles of scroll disks, analysis of the advantage of general scroll-type profile and its importance in scroll disks’ design were conducted first, then the characterization methods of general scroll-type profile and general scroll disks profiles were given out, and the wall thickness variation tendency of general profile was analyzed in the end. Based on the generation principle of general scroll-type profile and its conjugate profile, the pros and cons of equation method and the MATLAB programming method, two different methods used to generate general scroll-type profiles, were compared. When undetermined parameters are needed to be selected or determined rapidly, the MATLAB programming method seems to be more efficient and convenient. So the MATLAB programming method was eventually chosen to select the general scroll-type profiles to be used in the process of scroll disks modeling. After optimization, a general type profile with 3.25 scroll turns, 17.26 mm tooth pitch, 4.71 mm tooth thickness and 26.15 mm tooth depth was finally determined. Three dimensional modeling and motion simulation of the scroll disks of vacuum pump were completed with this profile by using NX software. The assembled model was similar to the real one. Under a constant driven with a speed of 90 degree/second, the meshing situation of orbiting and fixed scroll disks at 0°,90°,180°,270°of spindle rotation were observed by means of the step, the Displacement-Angle amplitude curve of the spindle and orbiting scroll disk conformed with the actual situation. Within the structural simulation based on Finite Element Method(FEM), the max amplitude of the displacement-node deformation of the orbiting and fixed scroll disks appeared at the head of the upper side of the scroll tooth. The max amplitude of the orbiting disk deformation was 8.176?m, and the max amplitude of the fixed disk deformation was 9.701?m. The displacement-node value in the circumferential direction, whether it is the orbiting or fixed scroll disks, was far more less than that in the radial and axial direction. Calculation showed that the stiffness of this material could resist the elastic deformation of scroll disks. The orbiting and fixed scroll disks at the joint part of the tooth head and plate received most of the stress. The max Von Mises stress value of the element node here of the orbiting disk was 45.25 MPa, and the max Von Mises stress value of the element node here of the fixed disk was 37.22 MPa. According to the analyzing result of main stress, the strength of this material could bear the max main stress of the orbiting and fixed scroll disks.Based on the structural parameters optimization and FEM-based structural simulation of scroll disks, series of satisfying results were achieved. In this paper, a set of test plan was proposed, covering the design and simulation research of the selected general type profiles, optimized structural parameters, solid modeling and assembling, motion simulation and structural simulation, which may serve as a reference for the feasibility of the design and processing of scroll disks of vacuum pump in the future. Optimization and improvement in the structural characteristics of scroll disks will surely enhance the function and efficiency of scroll vacuum pump in vacuum oil-filter, which is of important scientific significance and engineering application value. |
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