PLANETARY GEAR DEVICE AND PLANETARY GEAR DEVICE DESIGN PROGRAM

摘要

A planetary gear device configured by combining a plurality of planetary gear mechanisms includes first and second planetary gear mechanisms sharing a carrier, wherein each planetary gear mechanism is composed of an internal gear I_k (k is an integer equal to or larger than 2) and a planetary gear P_k which is engaged with the internal gear I_k and revolves in a circumferential direction of the internal gear, the planetary gear P_k of each planetary gear mechanism is composed of a spur gear in the form of an external gear, the planetary gears P_k of the planetary gear mechanisms share a central axis or have central axes integrally connected to integrally rotate on a common rotation central axis line or are integrated with each other to integrally rotate on the common rotation central axis line in order to configure the entire planetary gear device as a two-stage gear mechanism, the planetary gear device is configured such that the number of teeth z_p1 of a first planetary gear constituting the first planetary gear mechanism and the number of teeth z_p2 of a second planetary gear constituting the second planetary gear mechanism are different from each other, the number of teeth on the internal gear I₁ is z_i1, and the number of teeth on the internal gear I₂ is z_i2, an addendum modification coefficient of the first planetary gear is x_p1, an addendum modification coefficient of an internal gear which is engaged with the first planetary gear and constitutes the first planetary gear mechanism is x_i1, an addendum modification coefficient of the second planetary gear is x_p2, an addendum modification coefficient of an internal gear which is engaged with the second planetary gear and constitutes the second planetary gear mechanism is x_i2, a power transmission efficiency of the planetary gear device having the addendum modification coefficients x_p1, x_i1, x_p2, and x_i2 is η, an addendum modification coefficient of the internal gear I₁ is x_i1, and an addendum modification coefficient of the internal gear I₂ is x_i2, and the addendum modification coefficients have relationships in which values selected from combinations of the addendum modification coefficients which maximize or submaximize the power transmission efficiency η within an allowable range of design specifications given in advance are combined.