1. What is the External Gear Pump Flow Equation?

The external gear pump flow equation calculates the theoretical flow rate of a gear pump based on its geometric dimensions and rotational speed. It provides an estimate of the pump's capacity and performance characteristics.

2. How Does the Calculator Work?

The calculator uses the external gear pump flow equation:

Where:

• \( Q \) — Flow rate (GPM)
• \( D_o \) — Outer diameter (inches)
• \( D_i \) — Inner diameter (inches)
• \( W \) — Width (inches)
• \( N \) — Rotational speed (RPM)

Explanation: The equation calculates the theoretical displacement volume per revolution and multiplies by the rotational speed to determine flow rate.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation is crucial for pump selection, system design, and ensuring proper hydraulic performance in various industrial applications.

4. Using the Calculator

Tips: Enter all dimensions in inches and rotational speed in RPM. Ensure outer diameter is greater than inner diameter. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical efficiency of external gear pumps?
A: External gear pumps typically have 80-90% volumetric efficiency, with actual flow being slightly less than theoretical due to internal leakage.

Q2: How does viscosity affect the flow rate?
A: Higher viscosity fluids may reduce actual flow rate due to increased internal resistance and leakage paths.

Q3: What are common applications of external gear pumps?
A: Hydraulic systems, lubrication systems, fuel transfer, and various industrial fluid transfer applications.

Q4: How accurate is this theoretical calculation?
A: This provides theoretical flow. Actual flow may be 5-15% less due to manufacturing tolerances, wear, and fluid properties.

Q5: Can this equation be used for internal gear pumps?
A: No, internal gear pumps have different geometry and require a different flow calculation approach.