Quantitative analysis on the non-similarity of thermal deformation of the gear

Gears as common machine elements are deformed when its temperature varies. One direct result is that the tooth shape of meshing gear is changed. Using the theory of heat and elastic mechanics, the involute cylindrical gear is taken for example. Calculation makes it clear that the total profile of gear after thermal deformation is different from the shape before thermal deformation. That is named non-similarity, and the non-similarity error is given. For proving the non-similarity existed in thermal deformation of Gear, a four-dimension equipment is adopted for experiment, which is able to realize rotated motion and rectilinear motion. The experimental result also shows that the non-similarity does exist in thermal deformation of involute cylindrical gear. Shared a common theory, the non-similarity is existed in the circular gear.