Approximate Displacement Calculation of External Gear Pumps Leave a comment

Gear pumps are components that provide flow by converting mechanical energy into hydraulic energy in hydraulic systems. Pumps can be divided into different groups according to displacement. We can define the displacement as the volume of fluid delivered when the drive shaft of the pump rotates one revolution. This is an important property that we use when calculating the flow rate.

We can usually determine displacement from the code written on the gear pump housing but sometimes the code on the pump body may not be visible. At this point, we would like to share two formulas that we can use practically, which will allow us to calculate displacement. Let’s consider the figures shown in the picture below as the drive and driven gear of the hydraulic gear pump.

Iletim Hacmi 243x300

W is the body width, c is the center-to-center distance of the shafts, D is the major diameter, d is the root diameter, and gW is the gear width. You should use “cm” in the calculation.

  • If we consider single gear,

Formul 1

This formula is easy to use and is sufficient for single gear calculation.

  • If we consider drive and driven gears together,

Formul 2

In cases where we are not sure about pump displacement, it is possible to calculate it approximately by using these formulas and find out a critical information about the pump.



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