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Spur / helical force components

Gear mesh force

z₁z₂

Inputs

User-entered torque at the stated gear pitch circle; transients are excluded.
User-entered operating pitch diameter; geometry is not derived.
User-entered transverse working pressure angle in degrees.
User-entered helix angle in degrees; use 0 for a spur mesh.

Results

Pitch-line tangential force

2,500

Declared-angle radial force

909.93

Declared-angle axial force

669.87

Resultant mesh force

2,743.5

Ft = 2T/dp; Fr = Ft·tan(αt); Fa = Ft·tan(β); FN = √(Ft² + Fr² + Fa²)

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Nearby: Axial response · Beam deflection & reactions · Elastic stability · Solid-shaft torsion

Method

Formula, when it applies, and when it does not

Calculate pitch-line tangential, radial, axial, and resultant force components from torque, pitch diameter, transverse pressure angle, and helix angle.

Ft = 2T/dp; Fr = Ft·tan(αt); Fa = Ft·tan(β); FN = √(Ft² + Fr² + Fa²)

When

  • Parallel-axis spur or helical mesh
  • Declared pitch diameter
  • Declared transverse pressure and helix angles
  • Static pitch-circle force approximation

Don’t

  • This is a static pitch-circle force decomposition for a user-defined parallel-axis spur or helical mesh. It excludes tooth geometry, mesh stiffness, shaft/bearing support, backlash, lubrication, vibration, tooth strength, durability, safety, and approval.

Shigley's Mechanical Engineering Design