Internal Ring Gear (also known as the Annulus or Ring Gear) is a core component engineered for high performance planetary gearboxes. Manufactured from high-grade alloy steel, this internal gear features precision-cut teeth that mesh simultaneously with multiple planet gears. It is designed to serve as the outer shell of the gearbox stage, providing the necessary reaction torque to achieve high speed reduction and torque multiplication in a compact, coaxial design.

Utilizing advanced carburizing and quenching processes, the gear achieves a hard, wear-resistant surface while retaining a tough core, ensuring durability under high cyclic loads. Available in both spur and helical tooth configurations, our internal gears are machined to tight tolerances to guarantee low backlash, quiet operation, and optimal load sharing between planets.

Structure & Manufacturing Process:

• High Precision Fabrication: Manufactured from forged high-grade alloy steel (such as 20CrMnTi, 42CrMo, etc.) to ensure complete internal grain flow integrity. Through processes of carburizing, quenching, and low-temperature tempering, the tooth surfaces achieve a hardness of HRC 58-62. This provides high wear resistance and surface durability while maintaining excellent toughness and impact resistance in the core.
• Tooth Profile Design: Available in both spur and helical gear configurations. Compared to spur gears, helical designs enable smoother meshing, effectively reducing operational noise and vibration while increasing the contact ratio, making them ideal for high-speed, heavy-load applications.
• Precision Machining: Teeth are roughed using hobbing or shaping processes. For applications demanding high precision (such as in AGVs or robotics), a gear grinding process is employed. This ensures that cumulative pitch errors and tooth profile tolerances are controlled to standards such as ISO Grade 5 or DIN Class 6 or higher, achieving extremely low backlash (< 3 arcmin).

 Belon Internal Ring Gear Production Capacity sheet

Internal Ring Gear Functional Characteristics:

• Power Splitting: As the ring gear, it meshes simultaneously with multiple planet gears, distributing the load evenly. This allows it to handle significantly higher torque compared to traditional parallel shaft gear systems.
• Compact Design: Its annular structure allows the input and output shafts to remain coaxial, greatly saving installation space. This makes it an ideal choice for integrated drive units.
• Long Service Life: Rigorous material selection and precise heat treatment processes ensure that the ring gear exhibits excellent fatigue resistance and a long operational life under prolonged cyclic loads.

Internal Ring Gear Key Features at a Glance:

• Material: Case-hardened alloy steel for maximum wear resistance.
• Tooth Profile: Precision ground helical/spur gears for quiet, efficient power flow.
• Versatility: Customizable tooth counts and diameters to match specific planetary ratio requirements 

Internal Ring Gear Applications

• Industrial Automation & Robotics: Essential for precision joint actuators in robotic arms, providing the high torque density required for lifting and positioning in a compact footprint .
• Machine Tools: Integrated into spindle drives and rotary tables where high rigidity and positional accuracy are critical for cutting and forming operations .
• Mobility & Logistics: Utilized in the drive wheels of Automated Guided Vehicles (AGVs) and electric forklifts, offering reliable power transmission in space-constrained chassis designs .
• Renewable Energy: Deployed in the pitch and yaw control systems of wind turbines, where they must withstand high torque loads and variable weather conditions with maintenance-free operation .
• Construction Machinery: Applied in large-scale rotating equipment such as excavator swing drives, utilizing large-diameter ring gears to handle extreme radial and axial forces