How To Calculate Gear Pump Displacement

Gear Pump Displacement Equation:

\[ Disp_{gp} = \frac{\pi \times (D_o - D_i) \times W \times Teeth}{2} \]

Outer Diameter (D_o):

inches

Inner Diameter (D_i):

inches

Width (W):

inches

Number of Teeth (Teeth):

unitless

Gear Pump Displacement (Disp_gp):

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1. What is Gear Pump Displacement?

Gear pump displacement refers to the volume of fluid displaced per revolution of the pump. It is a critical parameter in hydraulic systems that determines the pump's flow rate capacity and overall performance characteristics.

2. How Does the Calculator Work?

The calculator uses the gear pump displacement equation:

\[ Disp_{gp} = \frac{\pi \times (D_o - D_i) \times W \times Teeth}{2} \]

Where:

\( D_o \) — Outer diameter of gears (inches)
\( D_i \) — Inner diameter of gears (inches)
\( W \) — Width of gears (inches)
\( Teeth \) — Number of teeth (unitless)
\( \pi \) — Mathematical constant pi (approximately 3.1416)

Explanation: The equation calculates the theoretical displacement volume based on the geometric properties of the gear pump's rotating elements.

3. Importance of Gear Pump Displacement Calculation

Details: Accurate displacement calculation is essential for proper pump selection, system design, flow rate prediction, and efficiency optimization in hydraulic applications.

4. Using the Calculator

Tips: Enter all dimensions in inches. Ensure outer diameter is greater than inner diameter. All values must be positive numbers with teeth count being at least 1.

5. Frequently Asked Questions (FAQ)

Q1: What is the practical significance of gear pump displacement?
A: Displacement directly affects the pump's flow output and determines the system's hydraulic power capacity and speed requirements.

Q2: How does displacement relate to flow rate?
A: Flow rate (in cubic inches per minute) = Displacement (cubic inches per revolution) × RPM (revolutions per minute).

Q3: Are there different types of gear pumps with different displacement formulas?
A: Yes, external gear pumps, internal gear pumps, and gerotor pumps have slightly different displacement calculation methods.

Q4: What factors can affect actual displacement vs theoretical?
A: Manufacturing tolerances, wear, clearances, fluid viscosity, and operating pressure can cause differences between theoretical and actual displacement.

Q5: How accurate is this displacement formula?
A: This formula provides theoretical displacement. For precise applications, manufacturer specifications and actual performance testing should be used.