Constant displacement pump 1 delivers fluid through pipeline 6 to chamber a and from there through pipeline 7 to the right end of power cylinder 2, moving piston 5 to the left. Fluid from the left end of cylinder 2 is discharged to the tank. The pressure exerted by the fluid in chamber a on valve member 3 is counterbalanced by the action of spring 8 and the working pressure, transmitted through damping device 9. If the working pressure begins to increase due to an increased load on piston 5, valve member 3 shifts downward, reducing the opening between the cone of member 3 and seat 10. This raises the pressure developed by pump 1 until an equilibrium is reached in the forces acting on valve member 3. If the working pressure in cylinder 2 increases above the permissible value, ball valve 11 opens and fluid is discharged through passage d to the tank. As a result, valve member 3 moves upward an the pump is connected to the tank. The difference in pressure of the fluid entering and leaving flow-control valve 4 is maintained constant, ensuring a constant flow of fluid through the valve. The maximum permissible working pressure in the system can be regulated by changing the force exerted by spring 12 with regulating screw 13.
$4186$CHP,Dr$