Hydraulic Pump Torque Calculator

Hydraulic Pump Torque Equation:

\[ T = \frac{V \times P}{2 \times \pi \times \eta} \]

Required Torque (T):

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1. What is Hydraulic Pump Torque?

Hydraulic pump torque is the rotational force required to drive a hydraulic pump at a given pressure and flow rate. It's a critical parameter in hydraulic system design, determining the power needed from the prime mover (electric motor or engine).

2. How Does the Calculator Work?

The calculator uses the hydraulic pump torque equation:

\[ T = \frac{V \times P}{2 \times \pi \times \eta} \]

Where:

\( T \) — Torque (Nm)
\( V \) — Pump displacement (cm³/rev)
\( P \) — Pressure (bar)
\( \eta \) — Pump mechanical efficiency (decimal, 0-1)
\( \pi \) — Pi (~3.14159)

Explanation: The equation calculates the theoretical torque required based on pump displacement and system pressure, then adjusts for mechanical losses through the efficiency factor.

3. Importance of Torque Calculation

Details: Accurate torque calculation ensures proper motor sizing, prevents overload conditions, and helps in selecting appropriate drive components like couplings and gearboxes.

4. Using the Calculator

Tips:

Enter displacement in cm³/rev (available in pump specifications)
Enter system working pressure in bar
Typical efficiency values range from 0.85-0.95 for piston pumps, 0.80-0.90 for vane pumps, and 0.70-0.85 for gear pumps
For critical applications, consult pump manufacturer for exact efficiency values

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between theoretical and actual torque?
A: Theoretical torque assumes 100% efficiency. Actual torque accounts for mechanical losses through the efficiency factor (η).

Q2: How does pressure affect required torque?
A: Torque is directly proportional to pressure - doubling the pressure doubles the required torque.

Q3: Why is displacement important?
A: Larger displacement pumps require more torque at the same pressure, as they move more fluid per revolution.

Q4: What if I don't know the efficiency?
A: Use 0.85 as a default for initial calculations, but obtain actual values from pump specifications when available.

Q5: How do I convert the result to other units?
A: 1 Nm = 0.73756 ft-lb = 8.85075 in-lb. For lb-ft, multiply Nm by 0.73756.