Rotary feedthroughs for pneumatics
Pneumatic rotary feedthroughs for more pressure (air)
Technical data
Protection class
IP51 (higher on request)
Rotational speed
0-300 rpm
Housing material
Aluminium, Stainless steel
Number of implementations
1-24
Additional services
Combination of different feedthroughs
Media implementation specification
- Number of pneumatic/liquid feed-throughs: 1 – 24
- Connection sizes: M5, 1/8″, ¼”, 3/8″, ½”, 5/8″, 1″, 1¼”
- Straight or angled connections
- Pressure: up to 1300bar, 130MPa; 20000 psi, vacuum 0.01torr, 30HG
- Media: Compressed air or pneumatics, Vacuum, Hydraulic oil, Return oil, Water, Hydrogen, nitrogen, vapour, cooling water, coolant, hot water, acids, bases and much more
Product overview
All details about our slip rings can be found in our product overview
Single and multi-channel rotary feedthroughs: efficient solutions for compressed air transmission
In contrast to electrical slip rings, used for power, signal and data transmission, single-flow and multi-flow rotary feedthroughs enable the sealed transition of one or more gases, especially compressed air, between stationary supply lines and rotating components. Pneumatic rotary feedthroughs are essential for a variety of industrial applications where compressed air plays a central role in function and efficiency.
For example, the rotary union is located between a compressed air pipe and a rotating drum. The gas is held in the rotary union during rotation until the openings of the rotary union and the compressed air pipe meet. The gas is then released from the connection piece and the rotary heat exchanger is then filled with new gas.
Pneumatic rotary feedthroughs offer a sealed and leak-free solution that is essential for the operational safety and efficiency of your systems. Thanks to their precise design and high-quality materials, our rotary feedthroughs guarantee a long service life and reliable operation, even under extreme conditions. Our products master the particular challenge of tightness and resistance to overheating thanks to innovative technology and customised solutions.
What exactly is pneumatics?
Pneumatics uses compressed air to generate mechanical movements. This technology is popular in many industrial applications because it is clean, inexpensive and reliable. A typical pneumatic system consists of a compressor that compresses and stores air. This compressed air is then channelled through valves and pipes to actuators such as cylinders or motors that perform mechanical work. The advantages of pneumatics lie in its cleanliness, safety, simplicity and flexibility, which makes it a favoured choice for many industrial processes.
Functionality of the pneumatics
- Compression of the air:
- A compressor draws in ambient air and compresses it, thereby increasing the pressure. The compressed air is stored in a compressed air tank.
- Distribution of compressed air:
- The compressed air is channelled through a system of pipes and valves to the pneumatic components. Valves control the air flow and enable precise control of the movements.
- Actuating the actuators:
- Cylinders and motors convert the compressed air energy into mechanical movements. For example, a pneumatic cylinder can be moved by compressed air to perform a linear movement.
Advantages of pneumatics
- Cleanliness:
- Pneumatic systems use air that does not leave any contaminants behind, which is particularly important in the food and pharmaceutical industries.
- Security:
- In contrast to hydraulic systems, which are operated with oil, pneumatic systems do not run the risk of leaks that could lead to environmental pollution. Compressed air is also non-flammable, which reduces the risk of fires.
- reliability:
- Pneumatic systems are robust and can be operated in a variety of environments. They are less susceptible to temperature changes and corrosive environments.
- Easy maintenance and installation:
- Pneumatic systems are generally easier to install and maintain than hydraulic or electrical systems. They require fewer complex components and have a longer service life.
Importance of compressed air in industrial applications
- Automation:
- In the automotive and manufacturing industries, pneumatic systems are often used to automate production processes. They control robotic arms, assembly lines and tools that require precision and speed.
- Packaging industry:
- Pneumatic systems control packaging machines that need to perform fast and precise movements. Pneumatic cylinders move grippers, cutting tools and conveyor belts to make the packaging process efficient.
- Food processing:
- In the food industry, pneumatics are used to operate machines that fill, seal and package products. The cleanliness of the compressed air prevents contamination and ensures product safety.
- Medical technology:
- In medical technology, pneumatic systems are used to operate devices that require precision and reliability, such as surgical instruments and automation systems in the production of medical devices.
- Machine tools:
- In CNC machines and other machine tools, pneumatic clamping devices and tool changers enable workpieces to be machined quickly and precisely.
Rotary union
Choice of different housing materials
Various connection sizes for media feed-throughs
Mounting and bolt circle rotor
Optional rotary feedthrough with hollow shaft
Functionality of rotary feedthroughs for pneumatics
In pneumatic rotary unions, there are several critical factors that ensure their effectiveness and reliability:
- Tightness and leak-free operation:
- One of the most important requirements for pneumatic rotary unions is the ability to transfer compressed air without leaks. High-quality seals are essential to maintain pressure and minimise energy loss.
- Material selection:
- The materials must be corrosion-resistant and able to withstand the high pressure and temperature conditions often found in industrial environments. Commonly used materials include stainless steel and specialised plastics.
- Wear resistance:
- Pneumatic rotary unions must be durable and wear-resistant to ensure long life and reliable operation. The seals and bearings must be designed to withstand continuous movement and pressure.
- Speed and pressure ranges:
- The design must support both high speeds and various pressure ranges. This requires precise engineering and high-quality materials that can endure these stresses.
- Adaptability and versatility:
- Pneumatic rotary unions should be adaptable for different applications and configurations. Multi-channel rotary unions enable the simultaneous transfer of multiple media, such as compressed air, water, and electrical signals.
Differences from other types of rotary transmitters
Pneumatic rotary unions differ from other types of rotary transmitters due to several specific features and requirements:
- Media transfer:
- Pneumatic rotary unions: These are specifically designed for the transfer of compressed air and other gases.
- Hydraulic rotary unions: These unions are designed for the transfer of hydraulic fluids and therefore must handle higher pressures and the greater viscosity of hydraulic oil.
- Electrical slip rings: These rotary transmitters transfer electrical signals and power, and do not require seals for fluids or gases.
- Seal requirements:
- Pneumatic rotary unions: The seals must be particularly tight to prevent air pressure losses while also being durable enough to withstand wear from continuous movement.
- Hydraulic rotary unions: The seals must not only be tight but also chemically resistant to hydraulic fluids and capable of withstanding high pressures.
- Electrical slip rings: These do not require fluid-tight seals but must maintain stable electrical contacts without interruption.
- Design and materials:
- Pneumatic rotary unions: Must use materials that are lightweight yet robust against corrosion.
- Hydraulic rotary unions: Often use heavier materials that can withstand higher pressures.
- Electrical slip rings: These are made from conductive materials that ensure a constant electrical connection.
- Applications:
- Pneumatic rotary unions: Commonly used in the automotive industry, packaging industry, robotics, and mechanical engineering.
- Hydraulic rotary unions: Commonly found in construction and mining machinery, agricultural equipment, and manufacturing processes that require high forces.
- Electrical slip rings: Used for power and signal transmission in wind turbines, rotating camera systems, and radar devices.
Further areas of application for compressed air rotary feedthroughs
Pneumatic rotary unions are used in many industrial sectors, including:
- Packaging industry: Rotary unions are used to control and operate machine parts during the packaging process. Pneumatic grippers that pick up and place packages, as well as cutting and forming tools, are examples of their application.
- Automotive industry: In automotive production, rotary unions deliver compressed air to machine tools and assembly lines. They are used in robotic arms that lift and position body parts, as well as in stations that mount tyres or tighten bolts.
- Mechanical engineering: Pneumatic rotary unions integrate pneumatic systems into rotating machines and tools. CNC machines with pneumatic clamping devices and lathes with pneumatically operated tool changers are typical applications.
- Robotics: In robotics, rotary unions supply pneumatic drives and grippers used in automated systems and industrial robots. They enable precise movements and continuous compressed air supply.
- Aerospace: In this sector, rotary unions transfer compressed air into rotating systems necessary for the operation of aircraft components and space technologies, such as turbine systems that supply control elements.
Advantages of rotary unions
- Reliability: They provide a dependable solution for transferring compressed air into rotating systems, thus enhancing operational safety.
- Efficiency: By effectively controlling and supplying air, they optimise processes, save energy, and extend the service life of machine parts.
- Flexibility: Available in various sizes and for different pressure ranges, rotary unions are highly versatile.
Multi-channel rotary feedthroughs for pneumatics
Multi-channel rotary unions enable the simultaneous transfer of various media – such as compressed air, hydraulic oil, water, or electrical signals – from a stationary to a rotating system. They are essential when multiple processes run in parallel or when different media are required for the operation of a machine.
Examples from industry:
- Packaging industry: Here, multi-channel rotary unions allow the simultaneous transfer of compressed air, electrical signals, and other media, enabling precise machine control. Combined transfers of compressed air and water are used for cleaning and filling processes.
- Automotive industry: Multi-channel rotary unions supply assembly tools with compressed air, hydraulic oil, and control signals. They are used for tightening bolts, operating lifting devices, and in processes that combine the use of compressed air and hydraulic oil.
- Robotics: In robotics, they simultaneously transfer compressed air, water, and electrical signals to drives and sensors, enabling complex movements and precise controls. Compressed air is used for movements, and water is utilised for cooling or cleaning purposes.
- Aerospace: They supply aircraft and aerospace components with a combination of compressed air, hydraulic fluids, and control signals. In turbine systems, compressed air is used for controls, and hydraulic oil for control surfaces.
Tyre pressure control systems and pneumatic rotary unions
A dynamic tyre pressure control system is essential for modern agricultural and construction vehicles. Machines such as tractors and combine harvesters must operate on various surfaces, from sand and clay to asphalt. This requires constant adjustment of tyre pressure to extend the life of the tyres and minimise soil damage.
High tyre pressure provides more safety on the road and prolongs tyre life but causes the bulldozing effect on soft surfaces like fields and meadows, leading to deep tracks and high fuel consumption. Lower tyre pressure, on the other hand, increases the tyre’s contact area and reduces the bulldozing effect. It also prevents soil compaction and promotes water infiltration.
The dynamic adjustment of tyre pressure at the touch of a button is therefore crucial. Multi-flow pneumatic rotary unions are necessary to route the compressed air from the compressor through the stator to the rotating tyre component (rotor). Combined electrical rotary unions also enable the transmission of measurements to the driver’s cabin, eliminating the need for a separate electrical slip ring.
These systems can also be retrofitted to older machines. RotarX offers compact rotary unions that can be mounted either on the front edge of the axle hub or installed inside the axle, so that only the connection thread is visible from the outside.
Your customised solution
The path to a vacuum rotary feedthrough that is perfectly customised to your needs begins with a detailed consultation. We analyse your specific requirements, including the media to be transferred, the pressure and temperature conditions and the spatial conditions. This detailed information forms the basis for developing a solution that is precisely tailored to your requirements.
Our experts will support you from the initial analysis to the final installation and maintenance of your vacuum rotary feedthrough. In this way, we ensure that your systems work efficiently and reliably and last a long time.
It all depends on the seal
Our main concern when developing our technology and providing individual advice is to ensure a high level of operational readiness while simplifying installation, minimising maintenance requirements and at the same time ensuring a long service life. Achieving these goals is much more challenging for pneumatic rotary feedthroughs with standard or combined electrical media transmissions than for purely electrical slip rings or simple rotary feedthroughs. This is due in particular to the challenges associated with sealing and wear caused by friction.
The precise separation of the various media channelsand the wear on the seals pose the greatest design challenges. The rotation between the inner and outer housing leads to continuous friction, which is less of a problem with purely electronic slip rings. However, in applications where absolute tightness is required, the wear of rubber rings on plastic or aluminium is a limiting factor for the service life of the component. At rotarX, we have already successfully overcome these and other challenges for various industries.
The secret of our success lies in the use of balanced mechanical seals. In pneumatic or hydraulic rotary feedthroughs, for example, these ensure that only the actuating and restoring forces act on the seals rather than the full operating pressure, which leads to a significant increase in service life. In addition, we offer various seal ring materials such as ceramic, graphite or silicon carbide on request in order to be able to optimally meet the specific requirements of our customers. This helps to reduce maintenance costs and minimise friction on the seals.
Why pneumatic rotary feedthroughs from RotarX?
RotarX stands for outstanding quality and customised solutions in the field of rotating unions. Our many years of experience and our modular system enable us to offer over 50,000 different configuration options. This ensures that we can supply the ideal solution for every application, whether for simple or complex requirements.
Our expertise is particularly evident in the customisation of our products to the specific requirements of your processes. We attach great importance to the development and manufacture of our rotating unions:
- Durability: We maximise the service life of our rotating unions by using high-quality materials and innovative sealing technologies.
- Reliability: Our products are designed to function reliably even under demanding conditions.
- Ease of maintenance: We design our rotating unions to be easy to maintain, which minimises downtime and increases the efficiency of your processes.
With RotarX, you are choosing quality, innovation and a partner who understands your industrial challenges and offers solutions that make your processes more efficient and safer.
Practical slip ring solutions for your application
Product catalogue for all slip rings
Find out about the different slip rings in our current overview. Transmission technology for complex industrial and safety-relevant applications form the core of our product range. All products can be individually adapted to the applications in order to offer you added value. Premium engineering - that is our claim for every single product we manufacture. We would like to convince you of this.
Do you have questions or would you like advice?
You can reach us Mon - Fri from 8 am to 5 pm.