Gear-Type Flow Divider Valve

cylinder moving parallel

Cylinder actuator moving in parallel

The gear-type flow divider valve works like two hydraulic gear motors with attached shafts. The both motor must have to run at the same speed since their shafts are attached. Thus, the same flow goes through both sides. The flow is equally divided and the cylinders actuator extends simultaneously.

Gear-type flow divider has a pressure intensification potential problem. For example the load is removed from cylinder 2. The no-load pressure to extend Cylinder 2 is 65 psi, and the pressure to extend Cylinder 1 is 10 times higher at 646 psi. Suppose the pressure drop due to flow restriction through the flow divider is P = 9 psi. The pump will build pressure to P = 646 + 9 = 655 psi

The pressure drop across the cylinder 2 side is 655 – 65 = 590 psi. The side-2 motor torque due to this pressure drop is delivered through the coupled shafts to side 1. The side-1 motor has a torque delivered “into” its shaft; thus, it functions like a hydraulic pump and builds pressure on side 1. This pressure is higher than the 646 psi needed to move load at the desired speed. Under certain circumstances, the pressure could get to a level that causes damage. In chase of using a gear-type flow divider valve, the designer must always analyze the circuit to ensure that pressure intensification will not cause a safety problem.

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