Planetary Gear

A typical planetary gear set consists of four core components: sun gear, planet gear, planet carrier, and ring gear. Sun gears, located at the center of the system, are smaller external gears. Planet gears: Usually multiple (commonly 3-4) identical small gears that mesh simultaneously with both the sun gear and the ring gear. These planet gears are connected by a planet carrier. Planet carrier: A frame that supports and connects all the planet gears. The planet gears can rotate on their own axes (rotation), while the planet carrier rotates around the sun gear, carrying the planet gears with it (revolution). Ring gear: A large internal gear located on the outermost edge, whose internal teeth mesh with all the planet gears. A planetary gear set is an ingeniously designed gear system that, through different combinations of its four components—the sun gear, planet gears, planet carrier, and ring gear—achieves high transmission ratios, high load capacity, and multi-functional power transmission and speed change within a compact space. It is one of the core technologies for power transmission in many modern fields, from automobiles to spacecraft.

Features:

1. Coaxiality: The input and output shafts are on the same centerline, resulting in a very compact structure.
2. Power Splitting: The input power from the sun gear is simultaneously split and transmitted to the ring gear and planet carrier through multiple planetary gears.
3. High Load Capacity: Due to the load being evenly distributed among multiple planetary gears, it offers high load capacity, smooth transmission, and low noise.
4. Versatility: By fixing any one of the components (sun gear, planet carrier, or ring gear) and using the other two as input and output, different transmission modes can be achieved (reduction, acceleration, reverse, direct drive, etc.).

Advantages:

1. ​Compact structure and lightweight: Achieves a high transmission ratio with a coaxial layout.
2. High power density: The load is shared by multiple gears, allowing for the transmission of greater torque.
3. Smooth transmission and low noise: Multiple teeth engage simultaneously, resulting in minimal impact.
4. Versatile and flexible transmission ratio: Various speed ratios can be achieved by combining different fixed components.
5. Easy to implement differential function: If the planetary carrier is used as the input and the two sun gears (or the sun gear and the ring gear) are used as the output, a differential is formed, allowing the left and right wheels to rotate at different speeds (this is the core principle of an automotive differential).

BELON is leading custom planetary gear manufacturer in China and can provide our customers with high precision planetary gear sets as per your application request from sample to mass production. We provide a wide range of planet gear set from smallest module 0.3 to largest module 45.

When you begin your journey with BELON, we focus on understanding your application and needs,  this allows us to match you with the most suitable, tailor-made gear solutions—combining performance, precision, and economy for your success.

Planetary Gear Production Capabilities