How to improve the angle transmission error of the gearbox

Angular transmission error (ATE) is a core issue in precision gearboxes (especially planetary gearboxes and harmonic gearboxes), directly impacting positioning accuracy, motion smoothness, and noise. Improvements can generally be addressed in the following areas:

 Design Surface Improvement
Tooth Profile Modification

Appropriate tooth tip and root trimming, or crowning, can reduce angular error during gear meshing.

In planetary gears, trimming can balance error accumulation.

Gear Ratio and Module Improvement

Reducing the number of gear stages or selecting gears with a larger module can reduce error accumulation.

A high-tooth-count internal ring gear provides an optimal match for the planet gears, reducing transmission error.

Helical vs. Spur Teeth

Compared to spur teeth, helical planetary gearboxes offer more continuous tooth meshing, resulting in less transmission error and noise, but they introduce axial forces.

They are suitable for applications requiring high precision and low noise levels.

Backlash Control

Use preloaded springs or split gears to eliminate backlash and reduce angular transmission errors.

Harmonic reducers often use wave generators and flexible gears to achieve zero backlash.

 Process and Quality Control
Gear Quality Grade

Use high-precision gears of JIS N5 / DIN 5 grade or higher.

The main sources of error are tooth profile, tooth profile, and cumulative pitch errors.

Bearing Rigidity and Assembly Accuracy

High-rigidity bearings and precision assembly can prevent eccentricity and tilt.

Appropriate preload can improve positioning accuracy.

Casing Rigidity

Insufficient rigidity can cause deformation under load, amplifying angular errors.

Using a one-piece machined structure can effectively improve this.

 Testing and Correction
Error Measurement and Digital Compensation

High-end applications (such as robotics and semiconductor equipment) use laser interferometers to measure error curves, which are then compensated by the controller.

Choose the right reducer type.

Harmonic reducers: High-precision positioning, suitable for small loads and zero backlash requirements.

Precision planetary reducers: Excellent torsional rigidity, suitable for high-torque applications.

RV reducers: Low angular transmission error, suitable for robot joints.

 Summary:
Improving angular transmission error requires a combination of gear design improvements, high-precision manufacturing processes, increased rigidity, and backlash control.
For small error control, tooth profile correction and helical gearing can be used.
For extremely high precision requirements (e.g., <1 arcmin), a combination of high-precision manufacturing, zero-backlash mechanisms, and controller error compensation is required.