The working principle of planetary gearbox is based on the characteristics of planetary gears. Planetary gears can not only rotate around their own axis (autorotation) like fixed-axis gears, but also rotate around the axis of other gears (revolution) driven by the planet carrier. This special movement mode enables the planetary gearbox to achieve power splitting and torque distribution under different working conditions, thereby optimizing transmission efficiency and power output.

1. Sun gear: located in the center of the mechanism, usually as part of the input or output shaft. Its function is to serve as the starting point of power input.

2. Planetary gear: a small gear that rotates around the sun gear, usually evenly distributed by multiple planetary gears to balance the load. The planetary gear can rotate around its own axis (autorotation), and can also rotate around the axis of the sun gear with the planet carrier (revolution).

3. Planet carrier: a bracket that fixes the planetary gear, connects the planetary gear and allows it to revolve, and can be used as an input, output or fixed component. The planet carrier is usually disc-shaped, with multiple shafts evenly fixed on it. These shafts are distributed at an angle of 120 degrees, ensuring the stability and balance of the planet carrier.

‌4. Ring gear: The external ring gear that meshes with the planet gear is often used as a fixed or adjustable component. The function of the ring gear is to mesh with the planet gear and transmit power.

1. Design requirements: The design of the planetary gearbox should meet specific performance indicators, such as transmission efficiency, noise, vibration, etc. The transmission efficiency must reach 97%, and the noise and vibration values ​​must be controlled within a specific range to meet different application requirements.

‌2. Material requirements: Key components such as sun gear, planet gear, inner ring gear and planet carrier are made of high-strength and wear-resistant materials. For example, the sun gear is made of 20CrMnTi carburized steel, the planet gear is made of 18Cr2Ni4W, the inner ring gear is made of 42CrMo, and the planet carrier is made of QT500-7 ductile iron.

‌3. Manufacturing process‌: Precision processing techniques such as composite quenching and carburizing are used during the manufacturing process to ensure the surface hardness and core toughness of the components. For example, the surface hardness of the sun gear reaches HRC60-62, the tooth surface hardness of the planetary gear is 58-62HRC, and the core is maintained at 32-40HRC‌.

‌4. Performance requirements‌: Planetary gearboxes must have high transmission efficiency, compact size, low vibration and low return clearance. The transmission efficiency can reach 97%, the volume is 40% smaller than that of traditional reducers, the vibration value is less than 2.8mm/s, and the return clearance does not exceed 1 arc minute‌.

‌5. Testing and acceptance standards‌: Planetary gearboxes must undergo strict testing and acceptance after manufacturing, including dynamic balancing tests, life tests, etc., to ensure their reliability and durability in actual applications‌.

‌6. Application scenarios‌: Planetary gearboxes are widely used in various industrial fields, such as industrial robots, wind power pitch systems, medical equipment, aerospace, etc. In these applications, planetary gearboxes must have the characteristics of high precision and long life‌.

‌1. Realize multiple transmission functions: Planetary gear devices can achieve multiple functions such as deceleration, reversing, direct connection and acceleration by cleverly switching the positions of input, output and fixed parts. For example, during the deceleration process, when the sun gear remains fixed, the pinion will rotate and revolve, thereby realizing deceleration power transmission.

‌2. Improve transmission efficiency: The planetary gear device cleverly converts the position of the input section and the fixed part through a precise interconnected gear system, thereby producing different transmission ratios to meet various driving needs of the car. This design simplifies the transmission system and improves the efficiency of power transmission.

‌3. Adapt to multiple working conditions: Planetary gear reducers have multiple transmission modes to adapt to different working conditions. For example, the sun gear input can drive the planetary carrier output to achieve a specific speed ratio; the planetary carrier input can drive the inner ring gear to increase the speed in reverse; the dual sun gear input can achieve torque superposition; and the mechanical protection mechanism is triggered when overloaded.

‌4. Modular design: Planetary gear reducers adopt modular design, which is easy to maintain and upgrade. For example, the three-stage reduction unit can achieve flexible speed ratio configuration in a space with an axial length of only 320mm to meet the torque requirements of different workstations.

‌5. Improve load-bearing capacity and life: The core advantage of the planetary gear reducer lies in its load-sharing mechanical structure, which can achieve load diversion and improve load-bearing capacity. For example, the wrist reducer of the handling robot of the automobile welding line adopts a 5-planetary gear layout, and the measured life span exceeds 60,000 hours.