| 摘要 |
PURPOSE:To match a working liquid pressure circuit with the demand characteristics of a corresponding circuit and to improve the efficiency of the whole of a working pressure circuit by setting respective independent working liquid pressure sources to a lubricating circuit and a control circuit. CONSTITUTION:A control circuit 21 controls a given shift based on a line pressure PL produced by regulating the pressure of working oil, fed from a normally engine-drive oil pump 9 to a line pressure circuit 26, by means of a pressure regulator valve 23. Meanwhile, a lubricating circuit 22 regulates the pressure of working oil, fed from an oil pump 10 driven by the output shaft of a transmission to a delivery passage 14, to a given value and feeds the working oil through a check valve 36. Two lubricating parts 31 and 32 are lubricated by means of working oil after cooling is effected by an oil cooler 33. Since, as noted above, working oil is fed to the control circuit 21 and the lubricating circuit 22 with the aid of the pumps 9 and 10, respectively, the pumps 9 and 10 can be matched with the demand characteristics of corresponding circuits, and the efficiency of the working pressure circuit of an automatic transmission can be improved. |
