| 摘要 |
<p>A water pump 1 has a pulley 4 provided with an internally toothed gear 4d and an externally toothed gear 4e that is further in than the internally toothed gear 4d in a radial direction, a shaft gear 5 involved in transmission of power to and from the pulley 4, and a transmission mechanism 6 that mediates transmission of power between the pulley 4 and the shaft gear 5. The transmission mechanism 6 includes gears 6a and 6b that set a transmission gear ratio to a first value when the transmission mechanism 6 engages with the internally toothed gear 4d and set the transmission gear ratio to a second value different from the first value when the transmission mechanism 6 engages with the externally toothed gear 4e, a rocker arm 6e that switches an engagement object of the gears 6a and 6b on a pulley 4 side between the internally toothed gear 4d and the externally toothed gear 4e, and a DC motor 6f that drives the rocker arm 6e.</p> |
