Strength Analysis And Experimental Study Of Two-point Contact Bevel Gears Based On Equiangular Spiral Curve

Spiral bevel gear is a kind of mechanical transmission components for the purpose of transferring power efficiently, which has many advantages, such as high load capacity, big overlap coefficient and smooth transmission, and it has been widely used in aerospace, machine tool, automobile and other fields. In practical engineering application, the typical transmission form of spiral bevel gear is crossed axes or intersecting axes, which is a three-dimensional movement. Therefore, its force condition is more complicated than other gears. As the direct action surface of load bearing and power transmission, the meshing tooth surface is the key factor that affects the performance of spiral bevel gears. According to the basic principle of conjugate curves mesh, this paper proposes a new type of two-point contact bevel gears based on equiangular spiral curve, and carries out the researches of tooth surface contact strength theory and test technology of this new type gear. Major contents of the thesis are summarized as follows:(1) A new type of two-point contact bevel gears based on equiangular spiral curve is proposed and the mesh equations of the bevel gear based on conjugate curves are derived. A general method of constructing the tooth surfaces of two-point contact bevel gears based on equiangular spiral curve is proposed and the equations of these tooth surfaces are derived. What's more, the three-dimensional model of two-point contact bevel gears based on equiangular spiral, which have the 90 degree angle between axes, is established.(2) The contact strength calculation formulas of the tooth surfaces of point contact bevel gears based on equiangular spiral curve are derived. The contact strength and the meshing characteristics of tooth surfaces of two-point contact bevel gears based on equiangular spiral curve are analyzed by using the finite element method. The modification method of two-point contact bevel gears based on equiangular spiral curve is proposed, and the contact strength and the contact stress distribution of tooth surface are contrasted with these before modification. Analysis results show that this modification method can effectively improve the edge contact situation of two-point contact bevel gears based on equiangular spiral curve.(3) The prototype gearbox of two-point contact bevel gears based on equiangular spiral curve is completed. The performance test bench for the new type gearbox is built, and the comparative performance tests of gearbox of two-point contact bevel gears based on equiangular spiral curve and SEW gearbox, such as, efficiency test, temperature rising test and so on, are carried out. The performance test results show that the two-point contact bevel gears based on equiangular spiral curve have good transmission characteristics and broad application prospects.