A harmonic gearbox is a high-precision gear mechanism that utilizes elastic deformation to achieve speed reduction.
It consists of three main components:
Wave Generator: An elliptical cam with a flexible bearing that deforms the flexspline.
Flexspline: A thin-walled, cup-shaped metal component that is elastically deformable.
Circular Spline: A rigid internal gear with slightly more teeth than the flexspline.
Working Principle: As the wave generator rotates, it deforms the flexspline into an elliptical shape, causing the flexspline's external teeth to engage with the circular spline's internal teeth at the major axis ends. Because the flexspline has two fewer teeth than the circular spline, each full rotation of the wave generator results in a relative retrograde rotation of the flexspline by two teeth. This design offers compact size, light weight, high reduction ratios (50–300), zero backlash, and exceptional positional accuracy, making it ideal for industrial robots, aerospace, and precision machinery.