What is the module of a gear?

Module (m) is the ratio of pitch diameter to number of teeth: m = d/z. It defines tooth size. Standard modules per ISO 54: 0.5, 0.8, 1, 1.25, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 12, 16, 20 mm.

How do I calculate pitch diameter?

Pitch diameter d = m × z, where m is module and z is number of teeth. Center distance a = (d1 + d2)/2 = m × (z1 + z2)/2.

What is contact stress (Hertzian stress) in gears?

Contact stress σH is the compressive stress at the tooth surface due to the contact load. ISO 6336 calculates it based on tangential force, face width, gear geometry, and elastic modulus. It determines pitting fatigue life.

What is bending stress in gear teeth?

Bending stress σF is the tensile stress at the tooth root caused by the transmitted load acting as a cantilever on the tooth. ISO 6336-3 provides the calculation method. It determines tooth breakage resistance.

How do I select gear material?

Common gear materials: Case-hardened steel (58-62 HRC, σH_lim ~1500 MPa), through-hardened steel (250-350 HB, σH_lim ~800-1200 MPa), cast iron (σH_lim ~400-600 MPa). Higher allowable stress = smaller gears.

免費工程工具 #094

正齒輪計算器

依據 ISO 6336 計算正齒輪幾何尺寸與應力。輸入模數、齒數、齒寬與材質，即可獲得節圓直徑、中心距、接觸應力與彎曲應力。

ISO 6336接觸應力彎曲應力

結果

節圓直徑與中心距

—

接觸應力 σ_H

—

彎曲應力 σ_F

—

切向力 F_t

—

齒輪比

—

頂圓直徑 (d_a1 / d_a2)

—

幾何形狀

接觸應力（簡化版 ISO 6336）

彎曲應力（簡化版 ISO 6336）

⚠️ 注意： 本計算器提供簡化估算。完整的 ISO 6336 分析需額外係數 (KA, KV, KHβ, KHα, ZE, ZH, ZB, YF, YS, Yε)。僅供初步設計使用。