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Planetary Gearboxes

What is a planetary gearbox?

The internal structure of the planetary gearbox is an epicyclic gear train (also known as a planetary gear set) mainly constructed of four major parts: a sun gear, planetary gears, a ring gear and a planetary arm carrier. In this gear train, the ring gear is fixed while the sun gear (input shaft) driven by the motor is located in the center. The sun gear is driven and moves the planetary gears which are fixed on the planetary arm carrier. Every planetary gear rotates on its own axis while revolves around the sun gear. The planetary arm carrier is the output shaft of the gearbox that transmits the power of the motor when planetary gears rotate and orbit. The operation of such gear set looks similar to our planetary solar system and that is how it is named, a planetary gearbox.


Design of Planetary Gearboxes

A planetary gearbox is usually constructed from heavy-duty metal, such as steel or a steel alloy, that can help it react well to large shock loads. It may be custom designed for different applications with unique torque, load, and speed requirements. However, in all forms, because of the varying planet gears that revolve around the sun gear, a planetary gearbox is capable of producing many different reduction ratios. In more detail, any of the three components of the planetary gearbox may be the input, the output, or be held stationary in an application. This allows for a more excellent range and more possibilities of reduction ratios.


Advantages of using planetary gearboxes

High torque

As the load in a planetary gear box is shared among multiple planets; therefore, torque transmitting capacity of planetary gearbox is very high. The torque transmission capacity can be further increased substantially by increasing the number of planet gears.

High stability

The planetary gear box is highly stable due to an even distribution of mass and increased rotational stiffness. Torque applied radially onto the gears of a planetary gear box is transferred radially by the gear, without lateral pressure on the gear teeth.

High efficiency

Fewer power losses result in the high efficiency of planetary gearboxes. The gearing arrangement of planetary gears tends to transfer a maximum of input energy to the desired output, due to which efficiency as high as 97% can be achieved for the first stage of a planetary gearbox.


Where are planetary gearboxes usually used?

Planetary gearboxes are widely used in spring machinery, manipulators, textile machines, machine tool manufacturing, precision machining machine tools, aerospace industry, smart home, automobile manufacturing, shipbuilding industry, semiconductor equipment, printing machinery, food packaging, automation industry, industrial robots, Medical inspection, precision testing instruments, and automated high-precision electromechanical products industry.
Robot Industry
Material Handling


Frequently asked questions

What is the principle of planetary gearbox?
The principle of the planetary gearbox is a power transmission mechanism, which uses the speed converter of the gear to decelerate the number of revolutions of the motor to the required number of revolutions, and obtains a mechanism with a large torque. The gear with a small number of teeth on the drive shaft of the planetary reducer meshes with the large gear on the output shaft to achieve the purpose of deceleration. Ordinary reducers will also have several pairs of gears meshing with the same principle to achieve the ideal deceleration effect. The ratio of the number of teeth of the large and small gears is the transmission ratio.
What is the main transmission structure of the planetary gearbox?
The main transmission structure of the planetary gearbox is: planetary gear, sun gear, ring gear, drive motor and transmission shaft.

The planetary gearbox can be divided into three sections from the appearance: input section, deceleration section and output section.

Input section: The input section refers to the end connected to the motor. Including input shaft hole, input flange

Deceleration section: The deceleration section refers to the core section of the reducer, which looks like a box from the outside, but actually contains many core components, such as planetary gears, sun gears, and ring gears.

Output section: The output pin refers to the end connected to the equipment, including the output shaft and output flange.

What are the advantages of planetary gearbox transmission?
Small size, light weight, high bearing capacity, long service life, stable operation, low noise, large output torque, large speed ratio, high efficiency and safe performance. It has the characteristics of power splitting and multi-tooth meshing. The transmission efficiency of planetary gearboxes is generally more than 90%, and can reach more than 95%, which is widely used.
What are the planetary gearbox installation procedures?
The first step.
Before installation, to confirm that the motor and the gearbox are intact and strictly check that the motor and the gearbox connected to the dimensions of the various parts match, here is the motor positioning boss, input shaft and gearbox grooves and other dimensions and matching tolerances.
Step two.
Spin the screws on the dust hole on the outside of the deceleration delan, adjust the PCS system clamping ring so that its side holes are aligned with the dust holes, and insert the inner hexagon tightness. After that, remove the motor shaft key.
Step three.
Connect the motor to the gearbox naturally. When connecting, it is important to ensure that the gearbox output shaft is the same as the motor input shaft and that the outer flan is parallel. As if the heart degree is not consistent, it can cause the motor shaft to break or the gear of the reducer to wear out.
What are the precautions for installing planetary gearboxes?
During installation, it is strictly forbidden to hit with a hammer, etc., to prevent axial or radial forces too large damage to bearings or gears. Be sure to tighten the mounting bolts before swirling them tightly. Before installation, wipe the rust-proof oil of the motor input shaft, positioning boss and gearbox connection with gasoline or zinc sodium water. The aim is to ensure the tightness of the connection and the flexibility of operation, and to prevent unnecessary wear and tear.
Before connecting the motor to the gearbox, the motor shaft keyway should be perpendicular to the tight bolt. In order to ensure uniform force, the mounting bolts in any verse position are first screwed, but do not tighten, and then the mounting bolts in the other two verse positions are finally tightened one by one four mounting bolts. Finally, spin the tight force bolt. All tight bolts need to be secured and checked by the torque plate hand according to the indicated fixed torque data.
The correct installation between the gearbox and the mechanical equipment is the same as the correct installation between the gearbox and the drive motor. The key is to ensure that the gearbox output shaft is in the same heart as the drived part of the shaft.

World class manufacturer

"HZPT Transmission Machinery Co., Ltd. is a manufacturer of various types of gearboxes, planetary gearboxes, agricultural machinery gearboxes, cycloid gearboxes, worm gear gearboxes, and other transmission equipment."

HZPT Machinery

"All the gearboxes we supply are 100% made in China, from material to machining and manufacturing to provide products with high quality, high precision characteristics. With years of experience, we can help you select the part that best suits your needs and customize it to your exact specifications."

"Planetary gearboxes are universal, robust, high-precision gear trains that provide efficient power transmission when combined with servo motors or stepper motors. Due to their multiple advantages, these gearboxes have a wide range of applications and can get the job done no matter how complex or harsh the conditions."

planetary gearbox

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