To improve precision in estimation of output number of revolutions relative to the input number of revolutions of a transmitter of a so-called traction drive system.
A reduction gear RG comprises traction planetary rollers which includes, as rotary elements, a sun roller 10S, pinion rollers 10P, and a ring roller 10R. Driving power is transmitted by shearing force of transmission oil present between the rotary elements. In the reduction gear RG, an electric motor MG is connected to the sun roller 10S, the ring roller 10R is fixed to a stationary system S, and the power of the electric motor MG is transmitted to the wheel W connected to the carrier 10C. In the reduction gear RG, the number of revolutions of the wheel W is estimated on the basis of the specific sliding between the rotary elements and number of revolutions of the electric motor MG.
OKUMURA KAZUYA
YOSHISUE KANSUKE
YU YOICHIRO
MAEDA YOSHINORI
HOSOKAWA AKIHIRO