What is a Rotary Union?
A rotary union is a device used to seal a rotating part and a stationary supply passage, allowing for the transfer of fluids without leakage in between. Often called swivel joints, rotary couplings, and rotary manifolds, these useful devices are engineered taking into consideration factors like the fluid to be transferred, its pressure and temperature, and even the number of flow paths.
What Are the Components Of A Rotary Union?
A rotary union is made of a number of simple components like:
- Housing: A structure that holds all the components of a rotary union together and acts as a framework. The housing also contains an inlet port where the fluid-supplying line is attached.
- Shaft: The shaft is a hollow tube that facilitates the flow of media from the supply line to the rotating part.
- Bearings: Bearings are little parts that allow the device to rotate as required, and can either be roller bearings (like ball bearings or tapered bearings) or non-roller bearings (like thermoplastic bushings).
- Seals: Possibly the most important component of the lot, seals prevent the fluid leaking outside while the rotary union is actively in use.
What Are the Applications of Rotary Unions?
Rotary unions are useful enough to see everyday use in a number of markets, but are most noticeably used in the industrial automation and alternative energy fields. Today, these devices are so widespread that people often forget how important they are to the overall functioning of thousands of industrial machines worldwide.
Some of the most frequently-seen applications of rotary unions include:
- Bottle Filling and Capping: Beverage and shampoo bottles are filled and capped through automated systems, where rotary unions are used to feed the appropriate material from a central supply container into the bottles on a conveyor line.
- CNC Machine Cooling: Computerized Numerical Control Machines (or CNC Machines) made of metal require the delivery of coolant, which is facilitated by rotary unions. Coolant prevents the machines from overheating and maintains dimensional stability.
- Radar Cooling Systems: Electronic systems on mobile units like radar systems also require coolant since they are in constant use and generate a lot of heat. Rotary unions used in the cooling mechanisms for radar systems have a special design.
Selecting Materials for Rotary Union Seals
Traditional Compression Seals (like O-rings) are suited to many static applications, but they don’t fit the bill when it comes to rotary unions. Ideally, you want seals made of materials with the lowest friction coefficient to ensure maximum seal life and reduce the chances of material leakage. Polytetrafluoroethylene (PTFE) is often considered the best material for rotary union seals, as this thermoplastic material comes with an extremely low friction coefficient.
Getting the Best Rotary Unions and Seal Materials: The Takeaway
Because of how important seals are (and how easy it is to have seals made of the wrong material), it’s crucial you find a rotary union supplier who ensures to have the best quality material. Maco Corporation India is the authorized Deublin distributor across Pan-India, the one-stop-shop for industrial rotary unions. Contact us at our enquiry mail info@macocorporation.com to get the best quotes from our side.