Mounted bearing questions, clearly answered.

LILY Bearing|Bearing Answers
Home›Loads & life›How can torque and gear pitch radius be used to estimate tangential force at a bearing-supported shaft?

How can torque and gear pitch radius be used to estimate tangential force at a bearing-supported shaft?

LILY Bearing |

Mounted Bearings supplier category illustrationLILY BearingMounted BearingsCompare models and specificationsBrowse this category Advertisement · Category illustration

Best answer

Editor's pick

Calculate a tangential force with consistent length units

For the tangential component, torque equals force multiplied by pitch radius, so Ft = T/r.

The radius must use the length unit consistent with the torque. Dividing N m by millimetres without conversion creates a thousand-fold error. JTEKT separates tangential, radial and axial gear forces in its load guidance; the tooth geometry and gear type determine which additional components must be considered. A tangential-force result is therefore one input to a shaft load analysis, not a complete bearing load. Keep the gear's pitch radius, force directions and location on the shaft with the calculation.

LILY BearingAdvertisement · Mounted BearingsBrowse this category

Other answers (1)

Work from a gear force to a support question

With an illustrative torque of 100 N m and pitch radius of 50 mm, convert the radius to 0.05 m.

The tangential force is 100 / 0.05 = 2,000 N. If this were the only transverse force, applied midway between two idealised symmetric supports, the tangential-plane reactions would each be 1,000 N. Moving the gear outside the support span changes those reactions; adding other gear-force components changes them again. This example shows why “two bearings means half the force each” is a conditional result, not a general rule. Use the actual free-body diagram before selecting the equivalent load for either bearing.