Forged Internal Ring Gear for Planetary Gearboxes
The internal ring gear plays a critical role in modern power transmission systems, delivering smooth torque transfer, accurate meshing performance, and long-term durability. Manufactured through ring rolling forging and precision CNC machining, Weforging’s internal ring gears are engineered to meet demanding requirements in planetary gearboxes, construction machinery, industrial reducers, and automotive applications. With optimized mechanical strength and excellent dimensional stability, each gear ring supports reliable operation even in high-load or continuous-duty environments.
What Is an Internal Ring Gear?
An internal ring gear features involute teeth on the inner circumference, allowing pinions or planetary gears to engage from inside. Compared with external gears, internal gears offer:
More compact gearbox design
Lower sliding friction
Reduced noise due to opposite-direction meshing
Improved load distribution in planetary systems
Internal ring gears are widely used in planetary gear trains, hydraulic motors, slewing drives, and precision transmission assemblies.
Advanced Manufacturing Process
Weforging produces internal ring gears through a controlled, high-precision process:
1. Ring Rolling Forging (Hot Forging)
This method provides excellent structural density and strength. The forged ring achieves:
Uniform grain flow
Enhanced impact resistance
Superior fatigue performance
Low material waste compared to traditional forging
2. Heat Treatment
Processes such as normalizing, quenching & tempering, or carburizing are applied depending on application requirements. These treatments improve:
Surface hardness
Wear resistance
Stability under heavy loads
3. CNC Machining & Tooth Cutting
After forging, gears undergo precise CNC machining:
Inner tooth cutting (broaching / shaping / hobbing)
Face and bore machining
Runout correction
Fine finishing to achieve stable meshing accuracy
Every ring gear maintains consistent tooth geometry and tight tolerances across production batches.
Material Options
Internal ring gears can be produced from multiple high-performance steels, including:
42CrMo / SCM440 – high strength, excellent toughness
40Cr / 4140 – widely used for gear applications
20CrMnTi / 8620 – ideal for carburizing and wear-resistant gears
S355 / Q345 – general-purpose gear rings
Custom stainless and alloy steels upon request
Key Performance Advantages
Weforging’s forged internal ring gears offer:
High load capacity enabled by dense forged structure
Excellent wear resistance through heat treatment
Smooth, accurate meshing with optimized involute profiles
Long service life due to superior mechanical properties
Reliable performance under continuous or high-speed conditions
These advantages make our internal ring gears suitable for rigorous industrial environments.
Applications
Our forged internal ring gears are widely used in:
Planetary gearboxes for construction machinery
Industrial reducers and servo drives
Excavators, loaders, and cranes slewing & travel systems
Agricultural machinery powertrains
Electric motors and hydraulic motors
Robotics and automated machinery
Whether for high-precision motion control or heavy-duty torque transfer, Weforging delivers stable and reliable ring gears tailored to your needs.
Quality Assurance
Each gear undergoes strict testing:
Dimensional inspection
Hardness measurement
Tooth profile and pitch accuracy checks
Magnetic particle / ultrasonic testing (optional)
This ensures consistent performance and long-term reliability.
Contact & Customization
Weforging provides standard and fully customized internal ring gears. If you need tailored materials, tooth modules, heat-treatment profiles, or machining tolerances, our engineering team is ready to assist.
Contact us today to request drawings, quotations, or technical consultation.
