Planetary Gear Reduction Calculator RPM

Planetary Gear Formula:

\[ \text{Output RPM} = \text{Input RPM} \times \left( \frac{\text{Sun}}{\text{Sun} + \text{Ring}} \right) \]

Output RPM:

Planetary RPM:

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1. What is Planetary Gear Reduction?

Planetary gear systems (also called epicyclic gear systems) are compact, high-power density gear arrangements that can produce different speed ratios. They consist of a central sun gear, planet gears, a ring gear, and a carrier.

2. How Does the Calculator Work?

The calculator uses the planetary gear equation:

\[ \text{Output RPM} = \text{Input RPM} \times \left( \frac{\text{Sun Teeth}}{\text{Sun Teeth} + \text{Ring Teeth}} \right) \]

Where:

Input RPM — Rotational speed of the input shaft
Sun Teeth — Number of teeth on the sun gear
Ring Teeth — Number of teeth on the ring gear

Explanation: The equation calculates the output speed when the ring gear is held stationary, which is a common configuration in planetary gear systems.

3. Importance of RPM Calculation

Details: Accurate RPM calculation is crucial for designing gear systems, determining torque output, and ensuring proper operation of mechanical systems.

4. Using the Calculator

Tips: Enter input RPM (must be positive), number of teeth on sun gear (must be at least 1), and number of teeth on ring gear (must be at least 1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between output RPM and planetary RPM?
A: Output RPM is the speed of the carrier (output shaft), while planetary RPM is the rotational speed of the planet gears about their own axes.

Q2: What's the typical gear ratio range for planetary systems?
A: Single-stage planetary systems typically offer ratios from 3:1 to 10:1. Multiple stages can achieve higher ratios.

Q3: How does this change if the sun gear is fixed instead?
A: If the sun gear is fixed and input is through the ring gear, the equation becomes: Output RPM = Input RPM × (Ring / (Sun + Ring))

Q4: What's the efficiency of planetary gear systems?
A: Well-made planetary gear systems typically have 97-99% efficiency per stage due to power splitting among multiple planet gears.

Q5: Can I use this for compound planetary systems?
A: No, this calculator is for simple planetary systems. Compound systems require more complex calculations.