| 摘要 |
PURPOSE:To carry out the continuous control having a constant power for discharge power by carrying out the revolution control for a fixed delivery pump by the control signal supplied from a control circuit having the characteristic that the product of pressure and flow rate becomes constant, according to the output of a pressure sensor in a hydraulic pump. CONSTITUTION:A fixed delivery pump 2 is driven by an electric motor 1 and output the discharge power consisting of the pressure and flow rate into a main conduit 8 having a flow regulator 5 through a check valve 11 and supplies the power to a load. As for the discharge pressure in the main conduit 8, generation of the abnormal discharge pressure is prevented by a relief valve 6, and said discharge pressure is detected by a pressure sensor 7, and input into a control circuit 9. The control circuit 9 consists of a function generating circuit having the characteristic that the product of pressure and flow rate becomes constant, and the number of revolution of the electric motor 1 is controlled through a converter 10 by the control signal, and the continuous control having a constant power for the discharge power is carried out. Therefore, the hydraulic power having the constant power can be always supplied to the load, and the difference between the discharge power of the fixed delivery pump and the load power can be reduced, and power loss can be reduced.
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