Spur Gear PCD and Center Distance Calculator

Gear Formulas and Interactive Calculator

Understanding gears and their calculations is fundamental for various mechanical systems. Gears are widely used in machines to transmit motion and torque between machine components. The design and function of gears rely on certain parameters, including the number of teeth, module, center distance, and more. Below, we'll explore some key gear formulas.

Gear Calculations

The key elements involved in gear design are:

• Number of Teeth (Z): The total count of teeth on the gear.
• Module (m): A measure of the size of the teeth, defined as the ratio of the pitch circle diameter to the number of teeth.
• Pitch Circle Diameter (PCD): The diameter of the circle that passes through the midpoint of the gear teeth.
• Center Distance (a): The distance between the centers of two meshing gears.
• Outer Diameter (OD): The diameter of the gear, extending from the center to the outermost point of the teeth.
• Tooth Depth (d): The vertical distance from the top of the tooth to the bottom of the tooth space.

To calculate these values, we use the following formulas:

• Pitch Circle Diameter (PCD): PCD = m * Z
• Tooth Depth (d): d = 2 * m
• Outer Diameter (OD): OD = PCD + 2 * m
• Center Distance (a): a = 0.5 * (Z₁ + Z₂) * m, where Z₁ and Z₂ are the number of teeth on each gear.

Now, let's use an interactive tool to calculate the gear parameters based on the number of teeth and module.

Interactive Gear Calculator

Gear 1 - Teeth (Z₁):

Gear 2 - Teeth (Z₂):

Module (m):