Dynamic characteristics analysis of helical gears considering lubrication and temperature effects

At present, there are relatively few studies on the dynamic characteristics of the gearbox gear transmission system considering multiple factors such as temperature, lubrication and clearance. In this paper, the influence of temperature on lubricant viscosity and backlash is comprehensively considered, and the oil film damping force is introduced into the force between teeth. Combined with the factors such as gear coincidence, backlash, time-varying contact line length, time-varying mesh stiffness and driving wheel speed fluctuation, a single degree of freedom helical gear transmission model including temperature effect is constructed based on the lumped mass method and solved numerically. Then the bifurcation diagram, time history diagram, power spectrum diagram, phase diagram and Poincaré section diagram of the system characteristics changing with temperature are drawn, the following conclusions are drawn: when the temperature is high, the motion of the system is complex, which is quasi-periodic or chaotic motion, and the force between gear teeth increases significantly, so the gears are more prone to damage under high temperature; the higher the temperature is, the more obvious the influence of the change of helix angle and normal modulus on gear rattle is; the power loss of helical gear system has a negative exponential relationship with the variation of temperature approximately; with the increase of helix angle and normal modulus, the power loss of the system increases; the influence of normal modulus on power loss is greater than that of helix angle, but the influence of helix angle and normal modulus on power loss are less significant than the effect of temperature. The above provides the necessary basis for the rational design of the helical gears of the transmission.