Precision Sun Gears for Planetary Systems
Weforging manufactures precision forged sun gears for advanced planetary gear systems, delivering high torque capacity and balanced load distribution with exceptional reliability. Using premium alloy steels such as 20CrMnTi, 18CrNiMo7-6, and SCM415, each sun gear achieves outstanding toughness, surface hardness, and dimensional accuracy. Through integrated forging and CNC machining, supported by controlled carburizing and precision grinding, Weforging ensures long service life, consistent performance, and stable operation across demanding industrial applications.
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.
Sun Gear Manufacturing Process
Our sun gear production combines advanced forging, precision machining, and heat treatment to achieve superior mechanical stability.
Forging Stage – High-quality steel billets are heated and closed-die forged.
This refines the grain structure and improves core strength.CNC Machining – After forging, gears are precisely shaped on Mazak multi-axis centers.CNC turning, hobbing, and grinding ensure exact tooth geometry and smooth engagement.
Heat Treatment – Controlled carburizing and quenching enhance surface hardness and toughness.
Final Inspection – Each sun gear undergoes dimensional checks, hardness testing, and surface finish evaluation.
This integrated forging + CNC machining process ensures long service life and uniform performance in demanding conditions.
Available Materials for Sun Gear Production
Weforging selects materials according to your load, speed, and operating environment to achieve optimal performance.
Common alloys include:
20CrMnTi – delivers high toughness and excellent fatigue strength.
18CrNiMo7-6 – ideal for heavy-duty and high-torque planetary systems.
SCM415 / 4320 / 8620H – offers outstanding hardenability and superior wear resistance.
4140 / 4340 Alloy Steel – provides high strength and exceptional machinability.
Stainless Steel & Aluminum Alloys – perfect for marine, aerospace, and precision applications requiring corrosion protection.
Every batch undergoes full chemical analysis, ultrasonic inspection, and heat-treatment traceability to guarantee reliable and consistent performance.
Industry Applications
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.
Contact
Weforging delivers sun gears engineered for unmatched precision and strength.Through our advanced forging and CNC machining process, each gear offers superior durability, accuracy, and efficient torque transfer in planetary systems.Supported by ISO 9001:2015 quality control, every gear is built to perform under demanding conditions.
Contact Weforging today for custom-forged sun gears that keep your system running with lasting reliability.
