A calculation method of thermal deformation for double helical gear

Abstract

Thermal deformation caused by gear transmission is an important factor causing gear impact, vibration and partial load. Gear modification can effectively improve the effects caused by thermal deformation. The calculation of thermal deformation is the first problem to be solved before gear modification. This paper takes double helical gear as the research object and a calculation method of thermal deformation is proposed. Firstly, temperature of instantaneous meshing points on the tooth surface are measured and these discrete temperature values are fitted by the linear interpolation. Calculation formula of temperature distribution along gear radial direction is introduced. Combining both, tooth surface temperature field is obtained. Secondly, equation of tooth surface for double helical gear before and after thermal deformation is derived according to the tooth surface temperature field. Finally, an example is given. Compared with the given modification of thermal deformation, the calculated thermal deformation is almost equal to theoretical value. On this basis, the thermal deformation of double helical gear considering the installation error and machining error is calculated, which provides a theoretical basis for thermal deformation modification of double helical gear.

Cylindrical gear transmission errors influenced by temperature based on thermal network

“…Wiemann et al [16] analyzed the influence of thermal expansion on the gear profile and helix deviations of Physikalisch-Technische Bundesanstalt's (PTB's) large gear measurement standards The results of a 3D scatter linear model for involute gears thermal expansion are compared to ones obtained via the finite element analysis as well as the experimental results by a coordinate measuring machine (CMM). Wang et al [17] measured the temperature of instantaneous meshing points on the tooth surface, and these discrete temperature values are fitted by linear interpolation to establish the temperature distribution along gear radial direction, and then the gear thermal deformation is calculated. As gear thermal deformation under the influence of temperature lead to the variation of gear transmission errors, Trochta et al [18] carried out the test these errors for different oil temperatures in the gear box, and established the linear relationship.…”