Home Back

Inverse Involute Calculator

Inverse Involute Equation:

\[ \theta = \tan \phi - \phi \text{ where } \phi = \arccos\left(\frac{r_b}{r}\right) \]

units
units

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Inverse Involute?

The inverse involute function calculates the angle θ at which a point on an involute curve is located, given the base radius and the radius to the point. It's essential in gear design and other mechanical engineering applications.

2. How Does the Calculator Work?

The calculator uses the inverse involute equation:

\[ \theta = \tan \phi - \phi \text{ where } \phi = \arccos\left(\frac{r_b}{r}\right) \]

Where:

Explanation: The equation calculates the angle θ by first determining the pressure angle φ from the ratio of base radius to current radius.

3. Applications of Inverse Involute

Details: The inverse involute function is crucial in gear design, particularly for determining tooth profiles, contact points, and meshing conditions in involute gear systems.

4. Using the Calculator

Tips: Enter base radius and radius in consistent units. The base radius must be less than or equal to the radius for valid results. Results are shown in both radians and degrees.

5. Frequently Asked Questions (FAQ)

Q1: What is an involute curve?
A: An involute is a curve traced by the end of a string being unwound from a fixed cylinder (the base circle).

Q2: Why is the inverse involute important in gear design?
A: It helps determine the correct tooth profile and contact points between meshing gears.

Q3: What units should I use for the radii?
A: Any consistent length units can be used (mm, inches, etc.) as long as both radii are in the same units.

Q4: What if r < rb?
A: This is mathematically impossible as it would require calculating arccos of a value >1. The calculator will not produce results in this case.

Q5: How precise are the calculations?
A: The calculator uses PHP's built-in trigonometric functions which provide high precision results.

Inverse Involute Calculator© - All Rights Reserved 2025