Custom Internal Spur Gear with Gear Milling and Hobbing for High-Efficiency Equipment

1) Features of Internal Spur Gear

• Unlike external gears requiring external space, internal gears feature teeth distributed along the inner wall of a bore, enabling a coaxial layout for input and output shafts. This structure allows it to inherently “enclose” other components.
• It offers exceptionally high structural integration, incorporating functions such as bearings and housing walls into the gear itself, significantly reducing component count and system axial length.

2) Functions of Internal Spur Gear

• Its core function is to form the central external framework (ring gear) of planetary gear transmissions. In this capacity, it remains stationary or rotates slowly, achieving substantial reduction ratios and power distribution through meshing with planetary gears – a feat difficult for externally meshed gears to accomplish efficiently.
• Within more complex differential systems or power-split devices, internal gears serve as pivotal nodes for motion synthesis or decomposition, simultaneously receiving or transmitting two distinct motions.

3) Applications of Internal Spur Gear

• Widely employed in the steering mechanisms of tracked vehicles such as tanks and excavators, its concentric design perfectly accommodates the dual-side power input and final output layout requirements, being pivotal to achieving precise and smooth steering.
• Within the pan-and-tilt propeller units of marine propulsion systems, the internal gear serves as the core component for enabling 360-degree steering transmission. Its compact structure is of paramount importance for submerged equipment.