The harmonic reducer is widely used in many advanced fields such as robotics, photovoltaic equipment, and precision machine tools due to its high transmission ratio, simple structure, small size, light weight, and high precision. The internal gear reducer of the harmonic reducer is composed of a fixed inner gear rigid wheel, a flexible wheel, and a wave generator that causes the radial deformation of the flexible wheel. The internal gear transmission structure of the harmonic gear drive reducer is a new type of transmission structure. It uses the controllable elastic deformation wave generated by the flexible gear to cause the teeth between the rigid wheel and the flexible wheel to misalign relatively, thereby achieving the purpose of transmitting power and realizing motion.
The use of double circular arc tooth profiles in harmonic gear transmission can effectively improve the stress conditions of the flexible wheel tooth root and the transmission meshing quality, enhance load capacity, torsional stiffness, and fatigue life of the flexible wheel, and can reduce the minimum transmission ratio.
The wave generator is one of the key components of the harmonic gear reducer, mainly consisting of a flexible thin-wall bearing and a wave generator cam. There are many factors that affect the fatigue performance of components, mainly including size, surface shape, and mean stress. Typically, the fatigue performance of components can be improved by selecting suitable materials, improving structures, optimizing sizes, surface hardening treatments, adding surface protection measures, and improving processing methods. The use of a cosine cam wave generator can fully control the deformation of the flexible wheel, has a high load capacity, good stiffness, and is suitable for standardized mass production.
The flex spline is a flexible, cup-shaped component that is responsible for transmitting the motion generated by the wave generator to the circular spline. It features external teeth that engage with the internal teeth of the circular spline at specific points of contact. The elastic nature of the flex spline allows it to deform in accordance with the wave generator, thus enabling the smooth, harmonic motion that eliminates backlash and reduces mechanical errors.
The circular spline is a rigid ring with internal teeth that mesh with the external teeth of the flex spline. As the flex spline deforms, only a portion of its teeth engage with the teeth of the circular spline, ensuring precision and smooth operation. The circular spline remains stationary, while the flex spline rotates within it, creating the high reduction ratios and torque capabilities characteristic of harmonic gear drive reducers.
