1. What is a Hydraulic Motor RPM Calculator?

Definition: This calculator determines the rotational speed (RPM) of a hydraulic motor based on flow rate and motor displacement.

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM \) — Revolutions per minute
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( D_m \) — Motor displacement (cubic inches per revolution)
• 231 — Conversion factor (cubic inches per gallon)

Explanation: The formula converts flow rate to cubic inches per minute, then divides by motor displacement to determine revolutions per minute.

3. Importance of Hydraulic Motor RPM Calculation

Details: Proper RPM calculation ensures motors operate within their designed speed range, preventing damage from overspeeding or inefficient operation at too-low speeds.

4. Using the Calculator

Tips: Enter the hydraulic system flow rate in GPM and the motor displacement in cubic inches per revolution. Both 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 displacement for hydraulic motors?
A: Displacement varies widely, from small motors (0.1 in³/rev) to large ones (50+ in³/rev), depending on application.

Q3: Does this account for motor efficiency?
A: No, this is theoretical RPM. Actual RPM will be slightly lower due to volumetric efficiency losses.

Q4: How do I find motor displacement?
A: Check manufacturer specifications or motor model number, which often includes displacement.

Q5: What if my motor has variable displacement?
A: Use the minimum displacement for maximum RPM calculation, or current displacement setting for actual RPM.