Hydraulic Pump Displacement Calculator

Pump Displacement Formula:

\[ V = \frac{\pi}{4} \times (D^2 - d^2) \times W \]

Pump Displacement (V):

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1. What is Hydraulic Pump Displacement?

Hydraulic pump displacement refers to the volume of fluid a pump can deliver per revolution of the pump shaft. It's a critical parameter in hydraulic system design that determines the pump's flow capacity and system performance.

2. How Does the Calculator Work?

The calculator uses the pump displacement formula:

\[ V = \frac{\pi}{4} \times (D^2 - d^2) \times W \]

Where:

\( V \) — Pump displacement (cm³/rev)
\( D \) — Outer diameter of the pump gears (cm)
\( d \) — Root diameter of the pump gears (cm)
\( W \) — Width of the pump gears (cm)
\( \pi \) — Mathematical constant (~3.1416)

Explanation: The formula calculates the volume between the outer and root diameters multiplied by the width of the gears, representing the fluid volume displaced per revolution.

3. Importance of Pump Displacement

Details: Pump displacement is crucial for determining system flow rates, selecting appropriate pumps, and matching pump capacity to system requirements. It directly affects the hydraulic system's speed and force capabilities.

4. Using the Calculator

Tips: Enter all dimensions in centimeters. Ensure outer diameter is larger than root diameter. Measurements should be taken from gear specifications or precise physical measurements.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between displacement and flow rate?
A: Displacement is volume per revolution (cm³/rev), while flow rate is volume per time (L/min). Flow rate = displacement × RPM.

Q2: How does displacement affect system pressure?
A: Displacement doesn't directly determine pressure - pressure depends on load. However, higher displacement pumps can deliver more flow at given RPMs.

Q3: What are typical displacement values for hydraulic pumps?
A: Common ranges are 1-250 cm³/rev for gear pumps, up to 1000 cm³/rev for piston pumps, depending on application.

Q4: How accurate is this calculation for different pump types?
A: Most accurate for gear pumps. Piston and vane pumps may require manufacturer-specific calculations due to different internal geometries.

Q5: Can I use this for hydraulic motors?
A: Yes, the same formula applies for hydraulic motor displacement calculations.