1) Features of Internal Spur Gear

• When an internal gear meshes with an external gear, the contact occurs between convex surfaces. Compared to the contact between two convex surfaces in external meshing, this arrangement offers a larger contact area, significantly reduced contact stress, and theoretically higher contact strength.
• Owing to its annular structure, the gear body exhibits minimal deformation under radial forces, possessing high radial stiffness and stability. This contributes to maintaining meshing accuracy under load.

2) Functions of Internal Spur Gear

• In planetary gearboxes, the fixed ring gear bears the primary torque reaction force of the system. Its high rigidity provides a stable foundation for the entire planetary system, directly enhancing the torsional stiffness of the entire transmission assembly.
• During high-speed operation, multiple planetary gears simultaneously mesh with the inner ring. This not only distributes the load but also, through its superior contact conditions, enhances the system's resistance to pitting and wear under heavy loads.

3) Applications of Internal Spur Gear

• It serves as the core component driving the main gearbox of wind turbines and the rotating platforms of large-scale construction machinery. In these applications, the equipment must withstand immense and variable impact loads, where the high rigidity and load-bearing capacity of internal-tooth gears are pivotal to ensuring long-term reliable operation.
• In the design of worm gears for high-precision CNC rotary tables (specifically internal-tooth worm gears), their high rigidity and multi-tooth meshing characteristics enable backlash-free, high-precision indexing and positioning, meeting the demands of precision machining.