The time-varying meshing stiffness of gear is the most important parameter in the dynamic equation of the gear systems

but now the most usually way of obtaining the parameter is the finite element methods and it’s very low efficiency.The Ishikawa formula is the analytical method which was used to calculate the time-varying meshing stiffness

it’s high efficiency but it only considers the deformation of the tooth of the gear

what’s more

some parameter which was referred in the Ishikawa formula don’t have a certain way to get now.Aiming at these problems

in this paper

the calculation method of the unclear parameters and an improved formula of the time-varying meshing stiffness are presented.Compared with the Ishikawa formula

the improved formula consider the deformation of the gear web plate and bring less high harmonic excitation.And this paper introduces the calculation principle of multi-tooth time-varying meshing stiffness.