Research on dynamic characteristics and profile modification of marine helical gears

The dynamic characteristics of marine gearbox transmission system directly affect the fatigue life of gear and the transmission efficiency of the system. Yuan Yongchao et al. Considered the influence of tooth profile modification and tooth profile deviation, helix modification and helix deviation as well as the radial runout tolerance of ring gear on the tooth profile processing shape, and replaced the theoretical curve with the fitted error curve equation, thus establishing the actual gear profile model with modification and error; Zhang lock Huai, etc. considered the factors such as gear backlash, torsional load excitation and meshing stiffness excitation, etc By establishing the rattle model of gear system, the slapping characteristics under different excitation amplitudes of rotating speed are obtained; Tang Jinyuan et al. Study the distribution of stress points on the tooth surface under the influence of rotation speed and impact force fluctuation based on the established gear meshing contact finite element model for the external excitation problem of gear transmission; Yuan Yaya et al. Took the comprehensive elastic deformation in the direction of meshing line as the modification Short profile modification has better modification effect, and quadratic curve and sinusoidal curve are fitted as new modification optimization curve, which eliminates the sudden change of stress during gear meshing; Zhang Xijin et al. Proposed topology modification methods of tooth profile modification such as drum profile modification and arc modification of tooth profile cutter, studied the influence of geometric parameter error and transmission error on contact, and obtained a new modification method Pramano studied the vibration and noise of gear transmission system, considered the influence of gear transmission error, analyzed the dynamic characteristics of gear by using long, short parabola and straight line modification, and concluded that the short modification can reduce the contact stress of tooth root, while the long modification can reduce the vibration amplitude under heavy load After a lot of research on the optimization of tooth profile curve, it is concluded that less modification can meet the modification requirements of high coincidence degree gear.

To sum up, it is of great significance to study the dynamic characteristics and shape modification method of gears to improve the transmission efficiency of marine gearbox transmission system.

By comparing and analyzing the results of dynamic characteristics of marine helical gear transmission, it is concluded that: because of the modification, the position of meshing in and meshing out is changed, resulting in the lag of sudden change of contact stress; although the long modification makes the change of load tend to be gentle and the amplitude of load mutation is reduced, the accuracy of meshing is affected and the average contact stress is increased instead of decreasing; the short modification not only reduces the load wave The dynamic range reduces the amplitude of load mutation, improves the load distribution on the tooth surface and improves the contact strength. This provides a reliable basis for the analysis of the gear box fatigue life.