Tooth Root Bending Strength Analysis And Experimental Study Of Curve-face Gear

Based on the face gear and non-circular gear,the curve-face gear pair is developed,which consists of a non-cylindrical gear and the conjugate curve-face gear.Combining the variable transmission ratio characteristic of non-circular gear and the intersecting axis movement characteristic of face gear transmission,variable transmission ratio between intersecting axis can be achieved through curve-face gear pair.Under the same conditions,curve-face gear pair have the advantages of light weight,small size and easy processing.As a result,the curve-face gears have a large potential application prospects in the construction machinery,automobiles and so on.This issue comes from the National Natural Science Fund Project ‘the theory of variable transmission ratio of face gear meshing transmission design and manufacturing technology research'(NO.51275537),to put forward a method suitable for the curve-face gear tooth root bending stress calculation,design the experiment bench suitable for curve-face gear and make experimental research on the bending stress of the curve-face gear.Aiming at the curve-face gear pair,this paper studies the following contents:According to the theory of space geometry and theory of gear meshing,the transmission model of the cure-face gear pair was established,the pitch curve of cure-face gear was deduced,the influence of the main parameters on curve-face gear transmission ratio was analyzed,and the positions of meshing point were derived.In view of the force situation of curve face gear,the contact condition during the mesh process,and the shape of curve face gear teeth,the possible failure position of the curve face gear was estimated.According to the basic theory of the curve-face gear transmission,the force situation of the curve-face gear under load was analyzed.The influence of basic parameters such as modulus,eccentricity and order on the pressure angle,normal force and so on were analyzed.The method to solve the bending stress of curve-face gear based on cantilever plate method was established.The calculation formula of the tooth root bending stress was deduced and the gear tooth root stress change rule of the curve-face gear in one cyclewas obtained.According to the request of experiment,to complete the tooth root bending stress dynamic measurement experiment and the rolling test experiment,three different structural for experiment bench were put forward,the advantages and disadvantages of them were analyzed;it is determined that the internal structure of the curve-face gear is adopted and the parts of the experiment bench are selected or designed and manufactured.The rolling test of curve-face gear was carried out in the designed experiment bench,and the contact trace during curve-face gear meshing was obtained.The dynamic measurement of the tooth root bending stress of the curve-face gear was completed,and the dynamic stress data of one periodic tooth root stress of the curve-face gear and the data of the stress on different positions along tooth width were obtained.The variation law of bending stress of one periodic teeth was analyzed.Based on the theoretical results and the experimental results,the position of the maximum stress in a period of the curve-face gear is obtained.The effects of eccentricity,order and modulus on the maximum stress of the tooth root are analyzed.Through the comparison of experimental measurement results and theoretical calculation results,the correctness and rationality of the proposed theory can be verified.