| 摘要 |
PURPOSE:To decrease a loss of power by providing a relief valve interposing in a branch passage in the downstream side from a pressure governing valve and connecting a downstream end of the branch passage to a lubricating oil passage communicating with a rotary part in a power transmission device. CONSTITUTION:An oil hydraulic pump 60 supplies pressure oil connected to a pressure oil receiving port 66 of a speed change valve 65 (control valve), additionally providing in a branch oil path 75 branching from an intermediate part in a delivery oil path 64 a pressure governing valve 76 and in its downstream side a relief valve 77, and a lubricating oil path 78 is connected to a point end of the branch oil path 75. Pressure oil in the delivery oil path 64 is adjusted by the pressure governing valve 76 to a required preset pressure and fed to the speed change valve 65, while surplus pressure oil more than necessary is discharged to the branch oil path 75 in the downstream side from the pressure governing valve 76, and relatively low pressure oil, set in the relief valve 77, is supplied to a rotary part in a power transmission device through the oil path 78. While pressure oil not less than the amount, able to pass through the oil path 78, is discharged from the valve 77 to an oil reservoir 62. |
