Hydraulic Closed Center System
In closed center system the hydraulic pump can rest when the oil is not required to operate a function. This circuit uses a control valve which is closed in the center to stop the oil flow from the pump. The figure above shows a hydraulic closed-center system.
On closed-center system, the quantity of oil to each function can be controlled by line size or valve size or by orificing. The other advantages of a closed-center system are as follows:
• The system does not require relief valves because the pump automatically shuts off when standby pressure is reached.
• The size of the lines, valves, and cylinders can be designed to fit the flow requirements of each function.
• Reserve flow can be maintained to ensure full hydraulic speed at low engine revolutions per minute (rpm).
• The closed-center system is more efficient on functions such as brakes, which require high force on a very little piston movement. By holding the valve open, standby pressure is constantly applied to the brake piston with no efficiency loss because the pump has returned to standby.
Categories: Hydraulic Circuits | Tags: Closed Center | Leave a comment