Precision Sun Gears for Planetary Systems | Power Transmission
Weforging manufactures precision forged sun gears for planetary gear systems. As the central gear in a planetary set, the sun gear must handle high torque and distribute loads evenly. Using alloy steels such as 20CrMnTi, 18CrNiMo7-6, and SCM415, we ensure both toughness and wear resistance. With CNC machining, carburizing, and grinding, our gears deliver long service life and reliable operation in demanding environments.
What Are Sun Gears?
In a planetary gear system, the sun gear is the central gear around which the planetary gears rotate. It serves as the primary input or output component, transmitting torque and motion within the gear train. By engaging with multiple planet gears simultaneously, the sun gear enables high torque density, compact design, and smooth power distribution. Its precision and durability are critical for applications such as automotive transmissions, aerospace systems, and industrial machinery, where reliable performance under continuous load is essential.
Premium Core Components for Demanding Applications
Technical Specifications
1. Manufacturing Excellence
Material Options:
20CrMnTi – Automotive-grade alloy for general-purpose transmission gears
18CrNiMo7-6 – Heavy-duty steel for high-load applications
SCM415 – Precision industrial steel with balanced toughness and machinability
Heat Treatment:
Carburizing Depth: 0.8–1.2 mm
Surface Hardness: 58–62 HRC
Core Hardness: 30–40 HRC
Tooth Accuracy Standards:
DIN 3962: Class 4–6
AGMA 2000-D04: Class 12
2. Advanced Machining Capabilities
| Process | Equipment | Tolerance | Surface Finish |
|---|---|---|---|
| Hobbing | Liebherr L302 | ±0.015mm | Ra 1.6μm |
| Grinding | Kapp Niles ZP12 | ±0.005mm | Ra 0.4μm |
| Hard Turning | Index C200 | ±0.01mm | Ra 0.8μm |
Our sun gears are widely used in:
Automotive transmissions — including EV and hybrid gearboxes, providing efficiency and torque control.
Wind turbines — ensuring stable torque transfer in main gearboxes with forged gear reliability.
Heavy equipment — such as excavators, cranes, and bulldozers, where forged gears outperform cast components under shock loads.
Industrial automation — including robotics, packaging lines, and reducers, where precision machining ensures smooth operation.
With proven supply chains to Europe and North America, Weforging supports OEMs in critical industries with cost-effective, durable gear solutions.
Quality & Support
Every sun gear undergoes material analysis, ultrasonic and MPI inspection, tooth profile measurement, and CMM verification. Heat treatment data and hardness reports are included for full traceability. Weforging operates under ISO 9001 and PPAP systems, giving buyers confidence in quality consistency. We also provide free DFM support, drawing verification, and custom profile optimization, helping customers reduce costs and improve performance. Standard production lead time is 25 days, with rapid prototyping available for urgent projects.
Submit Your Requirements:
- Upload 2D/3D Drawings（PDF, DWG, DXF, STEP, IGES）.
- Specify Material & Quantity & Technical Requirements
- Receive free DFM feedback within 24h.
