Rotating unions for hydraulics
Rotary feedthroughs for supplying and returning hydraulic oil
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, 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 for hydraulics
Rotating unions are crucial for the transfer of hydraulic oil between stationary and rotating machine parts. Other than Electrical slip rings, which are primarily used for the combined transmission of power, data and control signals, hydraulic rotary feedthroughs enable the safe and sealed flow of hydraulic fluids. Multi-channel versions of our feedthroughs are particularly suitable not only for transferring fresh hydraulic oil, but also for returning the used return oil to the designated container, all in the same component. This saves space and costs. One example of this is Rotating unions in hydraulic excavators.
Briefly explained: how do hydraulics actually work?
Hydraulics use pressurised fluids (hydraulic oil) to generate mechanical movements. This technology is widely used in industrial and mobile applications as it enables high forces and precise movements. A typical hydraulic system consists of a pump that pressurises the oil, a system of pipes and valves that control the flow of oil, and actuators such as cylinders or motors that perform the mechanical work.
The advantages of hydraulics include:
- High power transmission: Hydraulic systems can transmit large forces and control them precisely.
- Controllability: They enable fine control of speed and position.
- Reliability: Hydraulic systems are robust and durable, even under extreme conditions.
- Compactness: They offer high performance in a compact design.
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
Areas of application for rotary feedthroughs for hydraulics
Rotating unions for hydraulics are used in many industrial areas, including:
- Construction and mining machinery: Rotating unions are used in excavators, cranes and other heavy machinery to channel hydraulic energy to rotating parts required for lifting and digging operations. Examples include swivelling mechanisms and rotary axles.
- Agriculture: In agriculture, hydraulic rotating unions are used in machines such as tractors and combine harvesters to control hydraulic functions such as steering, drive and implements.
- Manufacturing industry: In manufacturing processes, rotary unions are used in machine tools and production systems to operate hydraulic clamping devices and drives. Typical applications include presses, punching machines and injection moulding machines.
- Wind power: In wind turbines, rotary unions enable the transfer of hydraulic oil to control the rotor blade adjustment and braking systems. These systems are crucial for optimising the performance and safety of the turbines.
- Marine and offshore: In the marine and offshore industry, rotary unions are used for hydraulic systems in ships and drilling rigs. They are essential for controlling winches, cranes and other deck equipment.
Advantages of rotating unions:
- Reliability: They offer a reliable solution for hydraulic oil transfer to rotating systems and thus increase operational safety.
- Efficiency: Through effective control and supply, they optimise processes, save energy and extend the service life of machine parts.
- Flexibility: Available in different sizes and for different pressure ranges, rotating unions are versatile.
Special requirements and solutions
Rotating unions for pressurised fluids such as hydraulic fluid require materials that are corrosion-resistant and suitable for use with oil. High-quality seals are essential to prevent leaks and extend the service life of the components. In high-pressure applications, they must be able to withstand the operating pressures and temperatures. This is the only way to ensure that hydraulic oil is supplied and used oil is returned in the long term.
Hydraulic rotary feedthroughs with leakage oil return
In industry, the return of hydraulic fluids is a complex process, especially under high pressure. Hydraulic rotary unions not only enable the supply of hydraulic oil to the rotating components, but also the return of leakage oil and return oil to the hydraulic oil reservoir. This is crucial for the efficiency and maintenance of machines such as excavators, cranes and mobile work platforms.
This enables continuous 360-degree rotation of the upper and lower machine parts without interference. Specialised rotating unions such as the MGCX models from RotarX can handle these tasks at pressures of up to 300 bar.
These rotary feedthroughs can also be used for other media such as compressed air (pneumatics), gas, vacuum, Water or oil can be used. With up to 24 channels, different media can be transmitted simultaneously, with individual configuration options ensuring that all media are separated from each other reliably and with low wear.
In wheeled excavators, pneumatic rotary unions are often used to transmit compressed air while hydraulic fluids for braking and steering systems are being passed through at the same time. This demonstrates the versatility and necessity of rotary unions in modern hydraulic systems.
Multi-channel rotary feedthroughs for hydraulics
Multi-channel rotary feedthroughs enable the simultaneous transmission of different media, power, data and signals – such as hydraulic oil, water, compressed air and Profibus – from a stationary to a rotating system. They are essential when several process steps run in parallel or when the space-saving combined transmission of different media in just one rotary union is required for the operation of a machine.
Examples from the industry:
- Construction and mining machinery: Multi-channel rotary feedthroughs supply swivelling mechanisms and rotary axes with hydraulic oil and electrical signals simultaneously, which enables the control and monitoring of machine functions. One example is the combined use of hydraulic oil for drives and water for cooling purposes.
- Agriculture: In agriculture, they enable the simultaneous supply of tractors and combine harvesters with hydraulic oil for implements and compressed air for tyre pressure control systems. This improves the efficiency and versatility of the machines.
- Manufacturing industry: In production plants, multi-channel rotary unions can transfer hydraulic oil for clamping devices and cooling water for machine tools in combination. This optimises the production process, saves a lot of space and reduces wear.
- Wind turbines: They transmit hydraulic oil for rotor blade adjustment and electrical signals for monitoring the system parameters simultaneously. This contributes to the efficiency and safety of wind turbines.
- Marine and offshore: In the shipping and offshore industry, they combine the transmission of hydraulic oil for cranes and winches with compressed air for control systems. This enables flexible and reliable control of deck equipment.
Your customised solution
Every customised rotary union begins with a comprehensive analysis of your specific requirements. We analyse your process conditions in detail, such as the media to be transferred, pressure and temperature requirements and the spatial conditions. Based on this information, we develop a customised solution that is precisely tailored to your needs.
Our experts will guide you through the entire development process: from the initial needs analysis, through design and production, to installation and regular maintenance. In this way, we ensure that your rotating unions function optimally and offer a high level of reliability over their entire service life.
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 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 RotarX?
RotarX stands for excellent quality and customised solutions in the field of rotating unions. Our extensive experience and flexible modular system enable us to offer more than 50,000 different configuration options. This enables us to provide the ideal solution for every application, whether simple or complex.
Our strength lies in the precise customisation of our products to the specific requirements of your processes. We attach great importance to this:
- Durability: We increase the service life of our rotating unions by using first-class materials and advanced sealing technologies.
- Reliability: Our products are designed for use in demanding conditions and offer maximum reliability.
- Ease of maintenance: We develop our rotating unions to be easy to maintain in order to minimise downtime and maximise the efficiency of your processes.
With RotarX, you can rely on a partner who understands your industrial challenges and offers customised solutions that make your processes safer and more efficient.
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.
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