| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a pressure of working oil on a hydraulic clutch under operation of an auxiliary speed change device interlocking with shift operation of a main speed change gear device and to increase an amount of lubrication oil fed to a hydraulic clutch, and to rapidly operate the hydraulic clutch of a main speed change device. SOLUTION: A flow rate regulating valve 50 is connected to the discharge circuit 49 of a hydraulic pump 48 and connected to the regulating flow circuit 51 of the regulating valve and a flow dividing valve 52 is provided. Working oil is fed to the hydraulic clutches 29F and 29R of an auxiliary speed change device and the hydraulic clutches 36, 37, 38, 45, 46, and 47 of a main speed change device. Lubrication oil is fed to the hydraulic clutch of the auxiliary speed change device by the surplus flow circuit 53 of the flow rage regulating valve, and it is preferable that flow rate control valves 70F and 70R to feed lubrication oil to only a hydraulic clutch under working without throttling lubrication oil is arranged in the feed circuit in a manner to be displaced in response to a clutch working oil pressure.</p> |
