Fundamental Theory And Experiments Study On Involute-circular Gear

The gearing transfers motion and power through the teeth driving alternately. Atpresent, the gearing is still one kind of the most extensively applied mechanicaltransmission in machinery and equipment, which is extensively applied in ships,weapons equipment, cement machinery, metallurgy, wind power, petrochemical, rubber,urban transport, lifting machinery and other fields. It is mechanical key basis parts inmanufacturing and national defence industry, which determine the equipment’sperformance in a great degree, and are gradually becoming an outstanding bottleneck inour national manufacturing. In our national medium-term and long-term scientific andtechnical plans, key basis components are listed as priority supported field. Thereby, ithas important theoretical significance and practical value to systematically carry out thestudy on the meshing theory, design method, manufacturing key technology andexperiment of high performance gear transmission components.A new tooth profile gear, involute-circular gear, is proposed by integrating involutegear’s advantageous edges with circular tooth gear’s advantages in this research. Theconcept of involute-circular gear is also defined, namely that choosing twosingle-valued curves which are corresponding engaged from the involute profilesbetween driving and driven wheels respectively, and replacing involute profile with theconvex and concave circular arc separately to form new tooth profile at any point ofthese curves to increases the radius of relative curvature and the contact strength.Because the path of contact points has the characteristics of involute, involute-circulargear’s center distance is insensitive.The main content of this thesis was as follows:(1) Based on differential geometry, basic principles of involute-circular gear wasdemonstrated in detail, and mesh characteristics were discussed. The general equationof tooth surface was established. Equation of meshing line was derived. Insensitivity tocentral distance variation on involute-circular gear was discussed.(2) Based on the definition of the slip ratio between the meshing pair, a newmethod that the slip ratio could be resolved by the conjugate equation was proposed;Through established meshing equation, the equation of path of contact points of convexgear and conjugated concave gear were derived; Sliding rate calculation method ofinvolute-circular gear was put forward and deduced. And examples were given. (3) Design method of involute-circular gear was proposed. Method of selection ofthe basic parameters and toothed parameters was determined. Design of theinvolute-circular gear tooth profile surface was completed. After examples were given,the three-dimensional modeling software UG was applied to establish athree-dimensional model of parameterized involute-circular gear.(4) Theoretic calculation euation of bending strength and contact strength werederived.(5) Both the tranditial involute gear and the involute-circular gear meshing pair’sfinite elements contact models were built, the analysis result of the contact pair rosolvedin ANSYS was compared for further reveals of contact characteristics ofinvolute-circular gear.(6) According to the experimental requirements, a transmission equipment whosemain transmission parts is involute-circular gear was designed. And a prototype ofinvolute-circular gearing was manufactured and assembled.(7) Efficiency test on the prototype of involute-gear was carried out to test whetherthe sample meet the expected technical requirements. And experiments show that theprototype involute cambered gear transmission is with high efficiency.