Design And Trial Production Of Multi-layer Perforated Steel Belt Drive System

Roller chain drive often causes the chain pitch to become longer due to wear,which leads to the phenomenon of tooth climbing and tooth skipping,which seriously affects the normal operation of the transmission system.The multi-layer perforated steel belt drive has the characteristics of no elongation,low lubrication requirements and being able to adapt to the harsh working environment.On the basis of the previous work,this paper mainly focuses on the steel belt pass,belt gear type,multi-layer belt drum theory,multi-layer perforated steel belt drive system design and mechanical punching method.The main research contents and results are as follows:?1?The study of the pass and the tooth of the steel strip with perforations.According to the characteristics of the meshing teeth in the existing meshing transmission system,the difficulty of manufacturing,and the existing research basis,etc.,first of all,three kinds of basic hole patterns are designed.Through the analysis of meshing interference,stress concentration and strength,two kinds of hole patterns,circular arc strip hole and circular arc rectangle hole,are preliminarily determined.Secondly,the basic tooth profiles such as square,trapezoid,involute and roller chain are designed.Through the analysis of meshing interference and transmission stability,two kinds of tooth profiles are preliminarily selected,i.e.conical tooth and round corner pyramid tooth.The final analysis shows that the meshing mechanism composed of circular arc strip holes and conical teeth is more reasonable.?2?Research on the bulging of multi-layer perforated steel strip.After analyzing and designing a kind of multi-layer cemented perforated steel strip,it is formed by winding a whole steel strip and the length of each layer is equal,and the holes are drilled on the multi-layer steel strip according to the tooth pitch.It is found that the bulge at the straight part of the multi-layer perforated steel strip will be transferred to the large and small pulleys when the distance between the teeth of the belt is properly reduced,so that the stress of each layer of the multi-layer perforated steel strip will be more uniform.?3?The design method of multi-layer perforated steel belt drive system is studied.According to the method to determine the structural parameters of the multi-layer perforated steel belt obtained in the previous study,taking the plate tooth roller multi-layer perforated steel belt drive of Dongfanghong 4LZ-2.5 self-propelled grain combine harvester as an example,the number of teeth of the main and driven wheels are determined to be 7 and 9respectively,and the speed is 975 r/min and 758 respectively r/min,the material of steel strip is 2205 duplex stainless steel,the width of multi-layer perforated steel strip is 20 mm,the thickness is 0.05 mm,and the hole spacing is 45 mm.Based on the optimization design module of workbench software,the optimal parameters of the straight-line segment length L_h,the small circle radius r₁and the large circle radius r₂of the circular arc strip hole are 12 mm,4 mm and 19 mm respectively.Finally,the number of perforations is 34,the number of layers is 50,the center distance between the two pulleys is 57 mm and the size of the pulley is determined.?4?Punching method and test of multilayer steel strip.First of all,the assumption of lamination punching for multi-layer steel strip is put forward.Secondly,the paper explores the deformation mechanism of multi-layer steel strip lamination common blanking,and puts forward zero gap blanking method and oblique edge blanking method to solve the problem that the middle layer of multi-layer steel strip is torn under tensile stress,resulting in serious deformation of blanking section and other defects.The theoretical and practical blanking tests show that the common blanking has a small blanking force,but the section quality is poor,which reduces the bearing capacity of the perforated steel strip;the common zero gap blanking of the multi-layer steel strip is adopted,and the middle layer steel strip mainly relies on the blanking force exerted by the convex and concave die for shear fracture,and the middle layer steel strip will not wrinkle due to tension,which can ensure the quality of the multi-layer steel strip blanking;and The inclined edge punching method,because the cut band waste is timely discharged from the middle hole of the punch,ensures that the middle layer steel strip always contacts with the punch edge,basically eliminates the possibility of the middle layer steel strip tearing under tensile stress,and ensures the punching quality.However,the punch strength of the inclined edge punching die is very low and easy to be damaged,and due to the existence of processing errors,the actual punching quality cannot be achieved Achieve the theoretical effect.The research results show that the zero clearance blanking method can basically ensure the formation of each belt layer of multi-layer steel strip under the shear stress,reduce the probability of cross-section cracks,and has important theoretical and practical significance for improving the working life of multi-layer perforated steel strip transmission system.?5?The trial production and transmission performance test of multi-layer perforated steel belt transmission system.A kind of multi-layer perforated steel belt transmission system is trial manufactured,and the performance test of the multi-layer perforated steel belt transmission system is carried out.The test results show that the transmission effect of the steel belt wheel without rim is better.The designed multi-layer perforated steel belt transmission system can run smoothly for 24 hours when the rotating speed of the driving wheel is 1056 r/min,and there is no tooth peeling phenomenon.