FAQ
Here you will find answers to your questions
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What is a rotary union and what are rotary unions used for?
Rotary unions are used in many industries to transfer media such as air, water, oil, grease or vacuum from a stationary to a rotating machine part (or vice versa), where the connection is permanent.
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How does a rotary union work?
In a rotary union, the two basic components, namely the rotor and stator, can rotate freely and endlessly against each other. Both parts are fixed to different components of machines. For explanation, we will deal here with a rotary union with two channels. On the stator there are two ports through which media to be transmitted are fed. The media are fed into the so-called non-contacting annular gap. Each medium has its own annular gap, which is sealed off from the other annular gap using different sealing techniques (depending on the medium, speed, pressure, etc.). The rotor has radial as well as axial bores through which the medium can flow out of the annular gap into the axial lines of the rotor and be conducted via connections to the points where the respective medium is required. The more channels a rotary union has, the larger its dimensions become.
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Which media can be transmitted via rotary unions?
Media such as water, emulsion, oil, grease as well as air/compressed air, gases or vacuum can be transmitted through a rotary union. Furthermore, there are rotary unions for the transmission of electrical power or electrical signals. These rotary unions are called slip rings. Moog GAT has decades of experience both in the production of slip rings and in the production of combinations of rotary unions and slip rings.
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With which pressures and which speeds can a rotary union be operated?
Depending on the application or design, Moog GAT rotary unions can cover pressures up to 600 bar, ultra-high vacuum up to 10-8 hPa and speeds up to 100,000 rpm. To find the optimal rotary union for your application, please use our product finder. Of course, our experts will also be happy to advise.
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How many channels can a rotary union have?
Moog GAT offers rotary unions with up to 30 channels. In addition to a variety of standard designs, we are happy to assist you as a competent partner for the implementation of your individual solution.
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How do I find the right rotary union?
To find the best possible rotary union for your application, detailed information on the operating parameters (media, pressures, temperatures, number of channels, connection types, mounting type, etc.) is necessary. For more information on the possible specifications of our portfolio, you can use our product finder. Of course, our experts are also available for consultation.
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Does Moog GAT supply only standardized rotary unions or are customized rotary unions also available?
We offer a wide range of standard designs and will be happy to assist you as a competent partner in implementing your individual solution at your side.
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How are rotary unions sealed?
The sealing systems used by Moog GAT vary depending on the application and range from wear-resistant mechanical seals and leak-free as well as dry-running contact seals to hydrostatically controlled gap sealing systems and elastic contact seals to magnetic fluid seals (ferrofluid) that are held in place by a ring-shaped magnetic field. Our experts will be happy to advise you on the selection of the best sealing technology for your application.
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Does Moog GAT also offer solutions for existing systems from other suppliers?
Moog GAT is specialized in customized solutions. We are happy to offer alternative / replacement solutions for your existing rotary unions.
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Does Moog GAT also offer combinations of rotary union and slip rings?
Yes. Thanks to Moog GAT's ROTOKOMBI system, all our rotary unions and slip rings can be combined with each other. Thus, the transmission of liquids, gases, vacuum as well as power currents, signals and data can be realized without interface problems between individual components.
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Are the Moog rotary unions GAT certified?
Moog GAT is certified according to DIN EN ISO 9001:2015.
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What is a slip ring?
A slip ring (also slip ring transmitter or slip ring body) is a component used in electromechanics for the continuous transmission of electrical power, analog signals as well as digital data between stationary and rotating parts. Electrical slip rings basically consist of a contact strip (contact ring) and a brush. Materials used in the manufacture of slip rings are precious metals, stainless steel, brass, bronze and carbon.
Moog GAT offers the highest contact quality and corrosion resistance with proven gold/gold transmission technology for the reliable transmission of signal and data streams as well as high performance. In addition, we offer further transmission technologies with contactless, capacitive as well as optical slip rings. -
How does a slip ring work?
An electrical slip ring, together with a gold spring wire, establishes a sliding contact, enabling transmission of electrical power or electrical signals between stationary and rotating parts.
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Where and for what purpose are slip rings used?
Slip rings are used in machines with rotating components to transmit electrical currents, analog signals and digital data. Slip rings are used, for example, in wind turbines and in medical technology (computer tomographs). Other areas of application include rotating components in machine tool construction, the automotive industry, rolling mills, the petroleum and semiconductor industries, the aerospace industry, tunnel construction, for seismic measuring systems and in the packaging industry.
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What data rates can be transmitted via slip rings?
The possible data rates depend on the transmission technology used. With our low-maintenance gold/gold technology, data is transmitted at a maximum of 100 Mbit/s. With contactless, capacitive transmission technology, we can realize data rates of 100 Mbit/s up to 2.5 Gbit/s - even in areas with high electromagnetic interference fields.
The highest data rate that Moog GAT delivers in its fiber optic rotary transmitters with non-contact, bidirectional transmission technology is a maximum of 30 GB/s. - How do I find the right slip ring?
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Does Moog GAT offer only standardized or also customized solutions?
Moog GAT is specialized in customized solutions. We are pleased to offer alternative / replacement solutions for your existing slip rings.
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What is the service life of a slip ring?
All sliding contacts are subject to material wear due to the abrasion caused by the principle. The service life of slip rings depends on the duration of use and the contact technology used. Our proven gold/gold transmission technology guarantees an unsurpassed long service life with consistently high signal quality.
Moog GAT can offer wear-free alternatives with both contactless, capacitive transmission technology and optical transmission technology. -
Does Moog GAT also offer solutions for existing systems from other suppliers?
Moog GAT is specialized in customized solutions. We gladly offer alternative / replacement solutions for your existing slip rings.
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In which temperature ranges can slip rings be operated?
The operating temperature when using our slip rings is -40°C to +80°C. For applications in areas with extreme cold, we offer heating systems for our slip ring systems.
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Does Moog GAT also offer combinations of slip rings and rotary unions for other media?
Yes! Thanks to Moog GAT's ROTOKOMBI system, all our slip rings and rotary unions can be combined with each other. Thus, the transmission of liquids, gases, vacuum as well as power currents, signals and data can be realized without interface problems between individual components.
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Are the slip rings from Moog GAT certified?
Moog GAT is certified according to DIN EN ISO 9001:2015. Our slip rings can optionally be certified according to Underwriters Laboratories / Canadian Standards Association and are available for different IP protection classes.
