1. What is a Hydraulic Motor Sizing Calculator?

Definition: This calculator determines the required displacement of a hydraulic motor based on flow rate and desired rotational speed.

Purpose: It helps hydraulic system designers and maintenance technicians properly size hydraulic motors for specific applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D_m \) — Motor displacement (cubic inches per revolution)
• \( Q \) — Flow rate (gallons per minute)
• \( RPM \) — Desired motor speed (revolutions per minute)

Explanation: The formula converts flow rate from GPM to cubic inches per minute (using the 231 conversion factor) and divides by RPM to get displacement per revolution.

3. Importance of Proper Motor Sizing

Details: Correct motor sizing ensures optimal performance, prevents overheating, and maximizes efficiency in hydraulic systems.

4. Using the Calculator

Tips: Enter the hydraulic system flow rate in GPM and the desired motor speed in RPM. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is 231 used in the formula?
A: 231 is the conversion factor between gallons and cubic inches (1 gallon = 231 cubic inches).

Q2: What's a typical flow rate for hydraulic systems?
A: Flow rates vary widely, but common industrial systems range from 5-30 GPM for medium-duty applications.

Q3: How does motor displacement affect torque?
A: Larger displacement motors produce more torque at the same pressure but require more flow to maintain speed.

Q4: What if my motor speed is too low?
A: Very low RPM may require a larger displacement motor or a flow divider to maintain proper lubrication.

Q5: Does this account for efficiency losses?
A: No, for precise sizing, multiply the result by 1.1-1.2 to account for typical volumetric efficiency losses.