New Method Of Meshing Design And Analysis For Hy-Vo Silent Chain

Hy-Vo silent chain is also called the rocker pin jointed silent chain,and it is a kind of high-end chain drive product series.In the field of advanced transmission that with high load and high-speed conditions,Hy-Vo silent chain shows the trend of replacing the normal silent chain to become the mainstream transmission component,so it has important research value and broad application prospect.However,recent studies have found that there is a coupling effect in Hy-Vo silent chain transmission system.Under the coupling effect,a variety of factors in the chain transmission system will influence and interact with each other,and eventually make the system transmission performance deviate from the design expectation.Therefore,further research on the meshing design and analysis method of Hy-Vo silent chain is the key to obtain the design technology that can reduce or avoid the influence of the coupling effect.Moreover,the feasibility and reliability of the chain transmission system can be improved.With the support of National Natural Science Foundation of China(No.51775222),the main research contents in this paper are as follows:The variable pitch characteristic of Hy-Vo silent chain is further analyzed.Based on the equivalent pitch equations under different hole shapes,a universal equation to calculate the equivalent pitch is proposed.Based on the rolling relation between adjacent pins of Hy-Vo silent chain,a new method to calculate the equivalent pitch is studied,and the principle of variable pitch characteristic and its influencing elements are analyzed.Based on the simple model of polygonal action,the boundary condition for zero polygonal action of Hy-Vo silent chain based on single sprocket is derived,the basic demands of the transmission system on the variable pitch characteristic are analyzed,the method to calculate the boundary value of rolling radius of rocker pin is obtained,and the formula to calculate the positioning offset angle of rocker pin is deduced.The meshing design of Hy-Vo silent chain is studied.The chain-sprocket-cutter meshing design system is improved,the concept of the chain positioning circle is proposed,the basic meshing condition and the algorithm to calculate the modification coefficient of involute sprocket are deduced.Through analyzing the relationship between the rack-gear meshing system and the chain-sprocket meshing system,the essence of the outer meshing between Hy-Vo silent chain and sprocket is analyzed,the additional condition for the outer meshing is obtained,and the pitch variation characteristic of the outer meshing chain is studied.By stiffening the chain,the pitch line relations among the rigid chain,the actual chain,and the hob are deeply analyzed when they are meshing with the involute sprocket(or negative displacement gear).The necessary condition of the existence of the inner-outer compound meshing Hy-Vo silent chain is obtained,the design method of the inner meshing profile of the inner-outer compound meshing chain is studied,and the meshing features of the inner-outer compound meshing mechanism are analyzed.The meshing evaluation method of Hy-Vo silent chain transmission system is researched.The contact limitation relationship between the Hy-Vo silent chain and the involute sprocket is analyzed.By building the accurate polygonal action model,the ideal and actual motion trails of the pitch point of the chain link at the transitional meshing state are analyzed,the algorithm to calculate the actual increment of chain pitch line at the radial direction is obtained,and the fluctuation model of Hy-Vo silent chain based on single sprocket is established.By decomposing and synthesizing the fluctuation of pitch point,the fluctuation evaluation method for Hy-Vo silent chain transmission system is obtained.Based on the evaluation method,some parameters in a certain Hy-Vo silent chain product are calculated and analyzed.The multi-body dynamics simulation and the noise and wear teats are carried out.The static drive characteristics of different chain plate hole-shaped Hy-Vo silent chain transmission systems with the same pin rolling surface features are researched,the center distance fluctuation differences of chain transmission system with different rocker pin rolling radius are analyzed,the dynamics characteristics of chain transmission system under different meshing mechanisms are studied,and the trend relationship between the fluctuation prediction curve and the simulating fluctuation curve is analyzed.By experimenting,the noise and wear characteristics for the outer meshing and inner-outer compound meshing Hy-Vo silent chains designed by the new method are analyzed,the noise performances for Hy-Vo silent chain transmission systems based on two design methods are comparatively analyzed,and the feasibility and rationality of the new method proposed in this paper are further verified by all the above results.By using the new method proposed in this paper,the polygonal action,meshing impact and system fluctuation of Hy-Vo silent chain can be effectively improved,and the noise value and wear degree can be effectively controlled.As a result,the new method of meshing design and analysis for Hy-Vo silent chain is scientific and feasible.To some extent,the new method can solve the inconsistency between the design expectation and the actual performance caused by the coupling effect,and its achievements can provide important theoretical guidance and practical basis for the development and large-scale application of Hy-Vo silent chain products.