Planetary gearboxes – find manufacturers and suppliers

Planetary gearboxes, also known as planetary gearboxes or epicyclic gearboxes, are a special type of gearbox characterized by their high power density, compact design and flexibility in the transmission ratio.

The planetary gearbox was invented by Scottish engineer William Murdoch around 1800.

Below you will find the structure and function of planetary gearboxes, an overview of types, their areas of application and their advantages:

Structure of a planetary gearbox:

A planetary gearbox typically consists of three main components:

1. The sun gear (central gear) is located in the center of the gearbox. It transmits the torque directly to the planetary gears or absorbs it from them.
2. Planetary gears surround the sun gear and are arranged evenly on a carrier (planet carrier). They rotate around their own axis and around the sun gear.
3. The ring gear surrounds the planetary gears. It is internally toothed so that it meshes with the planet wheels.
4. The planet carrier carries the planet wheels and enables them to move.

How a planetary gear works:

1. The movement of a planetary gearbox is determined by the relative movement of the main components (sun gear, planet gears, ring gear and planet carrier). Depending on which component is fixed or serves as the drive or output, different ratios and movement patterns can be achieved.
2. The transmission ratio is determined by the number of teeth on the gears.
   Example: The ratio between the sun gear, planetary gears and ring gear can increase or decrease gear ratios.
3. The planetary gears perform a combined rotation (around their own axis and around the sun gear), which distributes the torques evenly.

Types of planetary gearboxes:

There are different variants depending on the application:

1. Single-stage planetary gearboxes:
   For simple applications with a limited transmission ratio.
2. Multi-stage planetary gearboxes:
   For applications that require high transmission ratios.
3. Coaxial or concentric planetary gearboxes:
   For applications where the input and output must be on the same axis.

Use of planetary gearboxes:

Planetary gearboxes are used in many industries and applications:

1. Automotive industry:
In automatic transmissions, planetary gearboxes enable a smooth adjustment of the transmission ratio at changing speeds.
In electric drives, they optimize the torque of electric motors.

2. Mechanical engineering:
In CNC machine tools, they ensure precise transmission and torque transmission.
Industrial drives use planetary gears in conveyor belts, mixers and lifting systems.

3. Aerospace:
In jet engines as compact gearboxes for turbines and propellers.

4. Wind turbines:
Planetary gearboxes transform the slow rotation of rotor blades into faster movements for generators.

5. Robotics:
The high precision and compact size are ideal for robotic applications.

Advantages of planetary gearboxes:

Planetary gearboxes have some significant advantages:

• The compact design enables high gear ratios in a small space.
• They have a high power density and can transmit high torques.
• Different combinations of the main components enable many variations in the transmission ratio.
• They have a low energy loss due to even load distribution.
• Their robustness makes them ideal for applications with varying loads.

Planetary gearboxes are extremely versatile and play a key role in modern drive technology. Their strength lies in their ability to transmit high torques efficiently, enable compact designs and offer a high degree of flexibility in the transmission ratio. They can be found in almost all branches of industry that require powerful and space-saving drive solutions.

Here are the most important aspects to look out for when buying planetary gearboxes:

When buying planetary gearboxes, it is crucial to know the exact requirements of the specific application in order to select the appropriate technical specifications and features.

• Determine the technical requirements carefully:
• The gearbox must be able to transmit the maximum torque of the application without failing.
• Take safety margins into account, especially for dynamic or alternating loads.
• Planetary gearboxes should be designed for continuous loading to avoid overheating or premature wear.
• Select a gearbox with the right ratio to achieve the desired speed and performance.
• Check whether a single or multi-stage gearbox is required.
• Backlash is particularly important in robotics or machine tools to ensure precise movements.
• Low backlash increases accuracy, but is often more expensive.
• Torsional rigidity is essential for applications with high stability and positioning requirements.
• Check whether the planetary gearbox is designed for the planned speeds. Also consider the thermal loads at high speeds.
• The bearings of the gearbox must be able to withstand the radial and axial forces of the application.
• Select a gearbox with a sufficient service life for the planned duty cycle.
• The gearbox should fit into the available space without compromising its function.
• Weight is particularly important in applications such as robotics, aerospace or mobile machinery where overall weight is an issue.
• Check whether a coaxial arrangement of input and output is required.
• Material of the gears such as high-quality steel for durable and resilient gears.
• Plastic gears are suitable for lighter applications or when a low noise level is required.
• Hardened and ground gears increase service life and efficiency.
• The quality of the ring gear made of robust materials is decisive for the load capacity.
• Planetary gears should have a high efficiency (>95 %) to minimize energy losses.
• In noise-sensitive applications such as medical technology or household appliances, a low noise level is important.
• If necessary, the gearbox must be designed for the temperature conditions of the environment (e.g. extreme heat or cold).
• Select a protection class according to the requirements (e.g. IP65 for dust and splash-proof applications).
• Check whether the gearbox has permanent lubrication or requires regular maintenance.
• Look for certificates such as ISO 9001, CE, or specific industry certificates (e.g. for aviation or medical technology).
• Check the warranty services and the availability of spare parts.
• Consider not only the acquisition costs, but also the life cycle costs:
• Short delivery times can be crucial, especially in time-critical projects.

The purchase of planetary gearboxes requires a careful analysis of the application's requirements. Aspects such as torque, transmission ratio, precision, materials and efficiency are essential. Comparing different suppliers, checking certifications and taking life cycle costs into account ensure that the gearbox is not only selected in the best possible way technically, but also economically.

Planetary gearboxes can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Planetary gearboxes from all over the world can be found on Exportpages.