Formula:
The module (m) of a spur gear is calculated by dividing the pitch diameter (d) by the number of teeth (z) on the gear. The formula is:
M = d / z
Units:
● Module (m): Millimeters (mm) is the standard unit for module.
● Pitch diameter (d): Millimeters (mm)
What's the Pitch Circle?
The pitch circle of a spur gear is an imaginary circle that defines the theoretical rolling contact between two meshing gears. It's crucial for determining the gear's speed and plays a key role in gear design and functionality.
Here's a breakdown of the pitch circle:
Concept:
Imagine a perfect circle drawn on a spur gear where the tops of the teeth are rolled back to form a smooth circle. This imaginary circle is the pitch circle.
The center of the pitch circle coincides with the center of the gear itself.
Steps to Calculate Module:
1、Measure the Pitch Diameter (d): The pitch diameter is the imaginary diameter of the gear where the teeth act as if they are rolled into a perfect circle. You can find the pitch diameter by directly measuring a gear you have, or by using the gear's specifications if it's a new gear.
2、Count the Number of Teeth (z): This is the total number of teeth on the spur gear.
3、Calculate Module (m): Divide the pitch diameter (d) by the number of teeth (z) using the formula above.
Example:
Let's say you have a spur gear with a pitch diameter of 30 mm and 15 teeth.
M = d / z = 30 mm / 15 teeth = 2 M
Therefore, the module of the spur gear is 2M.
Post time: Jun-17-2024