Research On Kinematics Analysis And Structure Design Of Vibrating Parts Of A Vertical Vibration Mill

As the development of technology, the demand of fine material granularity isgrowing up. Vibration mill is a kind of fine and ultra fine milling device with highefficiency, which has simple structure and low power consumption. The energy istransmitted from vibration system to grinding medium, and the grinding mediumwill cut, crash, skive, pulverize and mix the material by forms of impacting,rubbing and cutting.This dissertation designs further vibrating parts of a vertical vibration millaccording to the vibration theory. Make some experiments to testify the prototype'sfeatures of the vibration mill. The main contents of this dissertation are presentedas follows:1. The Basic Theory of Milling and Vibration MillThis part introduces the basic theory of milling, and gives a detail discussabout current development of milling machine, analyses its applications and someproblems still need to be solved, all of which make a theory foundation for thestructure design of vibration mill.2. The Principle of Vibration Mill and Factors affecting Grinding EfficiencyIn this part, the principle and several structure forms of the vertical vibrationmill are discussed. Generally, in order to improve the vibration frequency andlower the power consumption, the form of direct actuating by electromotor isadopted, using no other deceleration device but a coupling.It analyzes the factors affecting grinding efficiency. The vibration mill hasmany working parameters, and they have different effects on the efficiency. Themost important factors are vibration intensity (which is decided by vibrationfrequency and swing), the motion track of milling cylinder, and the filling ratio ofgrinding medium. The results of experiments prove that: it is a workable way toimprove efficiency by improving the vibration frequency and swing. Low powerconsumption is one of the most important features of vibration mill, and a lot ofefforts have been done to make it lower, such as lightening the vibrating parts massand choosing a suitable coefficient.3. Dynamics Model and Movement AnalysisEstablish a dynamics model of spring radial bending mode, and obtain itstheory radial stiffness, which is proved to be correct by experiments. According tothe model, build a dynamics model of the vibrating parts, and analyze its tracks inxoy plane and the vertical direction, and get the relational expression betweenswing, the radial stiffness, shock force, mass of vibrating parts, and electromotorspeed. This relation will help us to know the movement of grinding medium.Because the movement of grinding medium is very complex, so we neglect themovement in vertical direction, and make a simplified movement analysis. Fromthis analysis we gain the revolution radius and angular speed and rotation angularspeed of inner cylinder and center block.4. The Research and Design of Vibrating partsIntroduce several forms of eccentric block, particularly make a detail discuss onthe eccentric distance of the fan-shape eccentric block, and make the stressanalysis. Introduce the software ADAMS, model the self lock mechanism andanalyze it in ADAMS to ensure that it can work safely.Compute the stiffness and intensity of the supporting springs of the verticalvibration mill in detail, and design some parameters of cylinder helix springs, andcheck its intensity of the supporting springs. Beside, decide the load power ofelectromotor and make a suitable choice.5. Conclusion1. Based on the research of vibration mill and congener products, it analyzesthe factors affecting grinding efficiency, which offers an opinion for the design ofvibration mill.2. Analyze and compute the spring's radial stiffness, build a dynamics model ofvibrating parts of the vibration mill,and analyze the tracks in xoy plane: circle, and the radius is 226 ωωkmMr ??。3. Design further the structure of vibration mill, all of which make a theory foundation for the design of vibration mill. Introduce several forms and design of eccentric block, and make the stress analysis. Design the self lock mechanism and analyze it in ADAMS to ensure that it can work safely.4. Test the granularity of material by the filtration method, which proves that the vibration mill has a good trait, which makes foundation for the further research of vibration and the development into product. It can also be improved in following aspect:1. Build a dynamics model of the grinding medium,and analyze the factors affecting grinding efficiency, and compute the best numerical value of filling ratio.2. Build a dynamics model of the vibration mill in vertical plane,and analyze further the tracks in vertical plane, offers an opinion to compute the grinding efficiency and power of the vibration mill.3. Research on the power of the vibration mill. At present, to compute the power by experiential formula makes a waste of resource, so it is necessary to research the power of the vibration mill.4. Improve the grinding efficiency of the vibration mill. Improve the grinding efficiency efficiently by changing the size of eccentric block and the spring's radial stiffness, and so on.