Study On Impact Vibration Isolation Technology Of Rubber Roller Hulling

As a new self-service rice milling machine in urban communities,embryo-retained rice huller is closer to the end consumer compared with the application scenario of traditional rice processing equipment,and its noise and vibration of the embryo-retained rice huller is stricter than the traditional ones,thus,these problems cannot be neglected.Based on the engineering background,this paper takes the rubber roller as the research object,which inevitably causes vibrations in this small-size intelligent rice huller.Analyzing the continuous discrete impact on the rubber roller,the author applied multi-linkage bars in the roller to isolate the vibration,and it was an isolator which was composed of six pre-tensioned counter-pressure isolation bars installed in parallel with each other inside the roller.According to the studies of the shock-absorbing mechanism and mechanical characteristics of the six bars,the expressions of the relationship between the system's maximum offset and the impact transfer rate was derived.Through calculating and simulating,the designed shock isolator could lessen radial and circumferential shocks.It is concluded that the isolator is capable of absorbing the shock under the given maximum allowable displacement,which can reduce the transmission of the shock vibration to other connecting structures,and minimize the acoustic radiation.The main contents of this paper are as follows:1.As the key rotating parts of the huller,the load characteristics of the rubber roller were analyzed that it was excited by radial and circumferential repeated shocks.For the contradiction of good stability and high shock absorbing rate during operation,the author used the parallel arrangement of multiple pre-tensioned isolation bars as the isolating device,and proposed its principle mode and statics equations as well as the expression of its stiffness characteristics and initial static equilibrium position retention.It is concluded from the analysis that the isolation device maintains the central symmetry in the stiffness characteristics of all the normal directions of the circumference of the rubber roller,and the elastic force of the system under the actual stroke is linear,which makes preparations for the response calculation of the six-bar isolation system.2.The force amplitude and the main frequency of the impact on the roller were obtained by theoretical calculation.Combined with the measured statistics,the rationality of theoretical calculation was analyzed and the incentive force was determined.By using the approximate analytical method to study the dynamics of the system,the differential equations of motion were established.The excitation force overcoming the holding force of the system were decomposed by the first three terms of Fourier transform,and then the response expressions of the system were obtained by linear method and Duhaman integration,which laid a good foundation for the response analysis and parameter optimization of the isolated system.3.Taking the system's maximum offset and the root-mean-square value of the shock transmissibility as the aggregative indicator of the system,this paper derives the expression of relationship between the two indicators.Matlab was used to obtain the change curve of system parameters and comprehensive indicators,and it is concluded that the system could achieve a lower transmissibility by selecting a spring with greater stiffness and reducing the length of pre-compression under a given maximum displacement;Through ADAMS,quasi-static compression simulation and dynamic simulation under excitation are carried out on the system,to obtain the static stiffness and response curve of the system,as a way to get the shock transmissibility.Compared with the theoretical calculation and analysis,the isolation performance and the feasibility of the six-bar-linkage isolator are verified,which provides a solution for the similar rotary machined parts in the equipment.