Bearing Reaction Force Calculator

Enter Bearing and Load Data

Use downward loads as positive values. Use rightward axial load as positive. Enter clockwise applied moment as positive.

Example Data Table

Formula Used

This calculator applies static equilibrium to a shaft or beam supported by two bearings. Bearing A is treated as the support carrying axial and vertical reaction. Bearing B carries vertical reaction.

1) Uniform load total

W_udl = w × L_udl

2) Uniform load centroid

x_udl = (x_start + x_end) / 2

3) Sum of moments about Bearing A

B_y = [Σ(P × distance from A) + applied moment] / span

4) Sum of vertical forces

A_y = total downward vertical load − B_y

5) Sum of horizontal forces

A_x = − axial load

6) Resultant reaction at Bearing A

R_A = √(A_x² + A_y²)

7) Resultant reaction at Bearing B

R_B = |B_y|

If a reaction becomes negative, the real support force acts in the opposite direction. That usually indicates uplift or reversed loading behavior.

How to Use This Calculator

1. Select your preferred force and length units.
2. Enter the total member length.
3. Enter the positions of Bearing A and Bearing B.
4. Add up to three point loads and their positions.
5. Enter the uniform load intensity and its loaded range.
6. Enter the beam weight if you want self-weight included.
7. Enter any net axial load. Rightward is positive.
8. Enter any applied external moment. Clockwise is positive.
9. Press the calculate button.
10. Review reactions, equilibrium checks, graph, and export files.

Keep units consistent. For example, if force is in kN and distance is in m, the moment unit becomes kN*m.

Practical Notes

This tool is useful for quick checks on simply supported shafts, rotors, rollers, and beam-like members under static planar loading. It supports point loads, a partial uniform load, beam self-weight, axial load, and an applied couple moment.

It does not replace a full shaft design, dynamic analysis, fatigue study, or finite element model. Use a detailed method when geometry, speed, flexibility, vibration, or misalignment strongly affects the result.

FAQs

1) What does this calculator solve?

It calculates horizontal and vertical bearing reactions for a two-support member under static loads. It also reports resultant reactions, load totals, equilibrium checks, and a quick graph.

2) Why can a reaction become negative?

A negative result means the support force acts opposite to the assumed positive direction. For vertical reaction, that usually means a downward holding force or uplift condition is present.

3) Why does Bearing A carry the axial reaction?

The model assumes Bearing A is the locating support. That bearing resists axial force, while Bearing B behaves like a non-locating support carrying vertical reaction only.

4) How is the uniform load handled?

The calculator converts the uniform load into a single equivalent force. That force equals intensity times loaded length and acts at the centroid of the loaded region.

5) Can the supports be placed inside the member length?

Yes. The supports can be anywhere along the member as long as Bearing B stays to the right of Bearing A. This also allows overhang conditions.

6) Can I use different units?

Yes. You can label force as N, kN, or lbf, and length as m, mm, or ft. Keep all entered values consistent with the labels you choose.

7) Is this calculator valid for dynamic loading?

No. This page is for static equilibrium only. Rotating imbalance, shock, vibration, fatigue, and transient loads require a more advanced analysis method.

8) When should I avoid this tool?

Avoid it for three-dimensional loading, large deflections, nonlinear supports, flexible shafts, thermal growth, or bearing stiffness problems. Those cases need a more complete mechanical model.