| 摘要 |
PURPOSE:To improve the transmission efficiency and to control the output rotation speed smoothly between the normal turning and the reverse turning by transmitting the motive power through a mechanical transmission gear when the rotation speed of the output shaft is in the scope higher than a specific value, and through a hydraulic transmission gear when the rotation speed is lower than the specific value. CONSTITUTION:When the rotation speed of a motor 13 and that of an output shaft 14 are lower than a specific value, a controller 21 operates a clutch pressure control valve 24 to cut off the clutch 31 of a mechanical transmission gear 30 fixed to an input shaft 2, and transmits the motive power from a motive power source 1 to a driving wheel 100 through a hydraulic transmission gear 10. In this case, the output capacity of a pump 11 and the motor 13 is controlled through control valves 15 and 16 responding to the depression of an accelerator pedal 27. And the forward running and the backward running are controlled by a change-over device 26. On the other hand, when the rotation speed of the output shaft 14 is in the scope higher than the specific value, the clutch 31 is engaged to make the output capacity of the pump 11 and the motor 13 zero, and the transmission is carried out through a mechanical transmission gear 30. Consequently, the transmission efficiency can be improved, and the output rotation speed between the normal turning and the reverse turning can be controlled smoothly. |
