| Hy-Vo silent chain is an important type of silent chain products, whichcharacterizes good high-speed performance, strong bearing capacity, greatabrasion resistance, etc. The variable pitch characteristic of Hy-Vo silentchain can apparently depress chordal action, impact and noise during silentchain meshes with the sprocket, as a result the Hy-Vo silent chain is widelyused for automobile gear box, transmission box, industry pump and otherhigh velocity transmission. According to the difference of the meshingmechanism, the silent chain is divided into three types: outer meshingmechanism Hy-Vo silent chain, inner-outer meshing mechanism Hy-Vosilent chain and outer and inner-outer meshing mechanism Hy-Vo silentchain.Supported by the Project of National Natural Science Foundation ofChina the Meshing and Design Theories Based on the Multi-variant andNew Hy-Vo Silent Chain (50975117) and the Design Theory ofMultiaxial High Speed Silent Chain System Based on Complex ConstraintBoundary Conditions (51275207) and National High Technological andDevelopmental Plan Project(863)titled Digital Method Research and Platform Development Based on the Sophisticated and Divesified Hy-VoSilent Chain (2009AA04Z109)，the meshing mechanism of Hy-Vo silentchain, a deep research is conducted on the general design method of Hy-Vosilent chain’s multi variation characteristic and meshing design system anddynamic simulation technology and guide design method and fatigue testingmethod.Based on analysis and comparison of different Hy-Vo silent chain typesand meshing mechanism, a systematic study is carried on Hy-Vo silent chainmeshing mechanism variation and shape variation and parameters variationand other variation characteristics. Based on the development trend ofdiscipline and industry technology, this thesis firstly raises the concept ofmulti variation, and points out that the multi variation process which ischaracterized by meshing mechanism and transmission characteristics, is justthe process of Hy-Vo silent chain products innovation and upgrade, as wellas the inevitable trend of industry requirements and technology progress.Based on analysis and study of the theory of sprocket hob and rollingcut of sprocket, according to the meshing mechanism of Hy-Vo silent chainand sprocket, Hy-Vo silent chain meshing design system based on multivariation is firstly constructed, and point that regarding Hy-Vo silent chainworking plate shape as rolling hob shape is the essential condition of settingup Hy-Vo silent chain-sprocket-hob design system. By analyzing themeshing mechanism of Hy-Vo silent chain and sprocket, the theory that theintersection point of extension cords of attachment of center points of basiccircle of working plate next to Hy-Vo silent chain is firstly raised, which is fundamentally different from the correct meshing condition of sleeve rollerchain transmission and gear transmission.Based on inner-outer meshing Hy-Vo silent chain with two differentHV3noncircular benchmark holes of the same specification and pitchcharacteristic, through design calculating and analysis，the theory that undercondition of correct meshing of Hy-Vo silent chain-sprocket-hob, a series ofnew transmission with different parameters is designed by multi variablemethod, in order to satisfy different personalized need of machines. At thesame time, through the experiment of steady transmission of two chainsystem, it is indicated that the Hy-Vo silent chain design method based onmulti variation is scientific and feasible, and multi variation design method isan important means of realizing Hy-Vo silent chain products upgrade and theprotection of intellectual property rights.Based on the fatigue reliability test of precision transmission rollerchain, the fatigue test method of Hy-Vo silent chain is firstly researched, andit is mentioned that in order to save test time, the level of one load factor canbe raised in24F-N method test figures. The fatigue strength curve afterraising test load is more conservative. By comparison research of14F-Nmethod and24F-N method, the14F-N method can be adopted and the loadcoefficient can be raised when roughly estimating chain life. R=50%R-F-Ncurve can be gained by14F-N method; The fatigue life curves through14F-N method and24F-N method are basically consistent. At the same time,the fatigue test research is carried on to Hy-Vo silent chain, the resultindicates that the chain may not meet the satisfaction of fatigue performance when meeting the requirement of strength, which proved the importance ofchain fatigue life research.Based on the analysis of the role of silent chain guide plate and its effecton Hy-Vo silent chain assemble and stress, the Hy-Vo silent chain guideplate design method is firstly put forward by researching on Hy-Vo silentchain guide plate, and the finite element analysis and test research is carriedout. By researching, the bigger the circular arc radius Rg at the top ofbutterfly-shape guide plate waist, the better. In condition of meeting therequirement of guide plate strength, the height of Hg should be reduced, anddistance between the lowest point of middle arc and pin stress center shouldbe increased. The research indicates that clearance can be compensated bydesigning reasonable butterfly-shape guide plate in the process of drawing inHy-Vo silent chain. At the same time, the result can be used in engineeringpractice, and brings much economic benefits to related industries.Based on the analysis of multi-body dynamics contact searchingalgorithm, and through using dynamics simulation software Recurdyn, themulti chain kinematics and dynamics simulation is carried out on new Hy-Vosilent chain of three different plate types designed through multi designmethod. By comparison research on the polygon effect of three differentHy-Vo silent chain, the Hy-Vo silent chain plate designed by multi variablemethod can become a new product by orderly combination, which proves thefeasibility of multiple design method again. At the same time, throughanalysis and research of Hy-Vo silent chain dynamic trait, the result suggeststhat the contact force of two counter shafts of the plate of the same new Hy-Vo silent chain plate is totally different, so it is not simply to judge otherchain’s stress by analyzing one chain’s stress, which provides an importanttheoretical guidance for Hy-Vo silent chain dynamics research. |
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