抄録
The automatic transmission uses a combination of 2 or 3 planetary gear trains to get a desired speed ratio. Reduction in the fuel consumption of automobiles has become an important project. The authors designed and made a gear train testing machine which can mount the planetary gear trains to be used for an automatic transmission of a passenger car. Single planetary gear train was used for the first and fourth speed stages while two planetary gear trains were used for the second speed stage. The theoretical efficiency of the combined internal gear trains is calculated using theoretical equation when oil churning and bearing losses are taken into account together with tooth meshing losses.
