Research On Profile Modification And Meshing Rule Of Involute Cylindrical Gear

Involute cylindrical gear is one of the most widely used machinery and auto transmission part.It has the advantages of load-bearing capacity, stable load transmitting and performance. Gear technology is a synthesis technique with multidisciplinary and multi-field technology, and embodies the level of a country’s basic industry. With the development of science and technology, involute gear will be widely used in heavy load and high speed drive field which draw higher demand in design capability and development technique of gear. The design of asymmetric gear can maintain the advantages of involute gear, such as stable meshing, also has better adaptability and bearing capacity. Gear mesh is a complicated process on account of errors in manufacture and assembling, as well as the elastic deformation of system itself. Therefore, proper gear design, researches on analytical methods of gear mesh rule and meshing characteristics have great significance for meshing performance promotion of gear. So, the purpose of this paper is to explore new methods for gear design and analysis. Researches on the design and modification of the asymmetric involute gear tooth profile, wear and fatigue prediction of gear meshing, and modification technology of involute cylindrical gear under deformation system are analyzed.Based on meshing theory and coordinate transformation methods, the coordinate equations of the involute asymmetric gear profile are deduced, the gear contact mechanics models are established to analyze the influence of pressure angle and the value of load on the changing rule of gear meshing force, axial displacement and the contact stress. The distribution rules of contact areas under different meshing time are studied. In view of the asymmetric gear tooth profile modification, the involute slope modification method is proposed, the different modification parameters on meshing stiffness of gear meshing process and its spectrum characteristics, transmission error, the contact stress, bending stress and the influence of the coefficient of load distribution among gear teeth are studied.Contact mechanics models are established based on the theory of wear to analyze the gear contact pressure distribution rules and the changing rules along different paths. The influences of the pressure angle and modification parameters to the gear contact pressure change rule are analyzed. Gear wear simulation models are established to forecast the wear abrasion height. The change rule of wear height before and after modification is compared. Based on the fatigue test of gear material, the rule of fatigue life before and after modification is done.Considering the influence of the deformation of gear transmission system, the influences on deformation of gear system by gear arrangement and component stiffness and the influences on gear misalignments by system deformations are analyzed. The laws of gear engagement with gear misalignments are studied. The multistage gear transmission system models are established according to the sub-model method considering system deformation. The misalignments under different paths and loads are obtained to carry on gear modification research considering the gear misalignments. The influence of various modification methods as parabolic tip relief, profile barrel relief, lead crown relief, lead parabolic relief and multi method modifications to the values of transmission and the peak-peak are studied. The studies are helpful to guide the gear modification design.