The function of a hollow axle design
In vacuum coating equipment, introducing rotational motion into a vacuum chamber is a common requirement. A hollow axle magnetic fluid feedthrough meets this need by allowing the passage of vacuum lines, process gases, or electrical signals through its central bore while the shaft rotates. This design supports the transmission of signals to control and monitor the coating process directly inside the chamber. One industry source notes these units are recognized as optimal solutions for introducing rotational motion into vacuum or differential pressure environments.
Key technical parameters for coating applications
Selecting the correct feedthrough depends on matching its specifications to the coating system's demands. The required vacuum level is the first consideration. Standard hydrocarbon ferrofluid is suitable for most high-vacuum needs, but reactive gas environments need perfluorinated options for chemical stability. Published specifications for a hollow axle flanged model list an operating vacuum pressure down to 10^-6 mbar. Its helium leakage rate is below 10^-12 mbar.l/sec, which meets the need for zero leakage in sensitive processes like semiconductor fabrication.
Operational limits and cooling
The operating environment imposes clear limits on feedthrough performance. The same model specifies a temperature range of 0 to 80 degrees Celsius and is rated for use with inert gas. To maintain performance within this range, especially under high rotational speeds or thermal load, water cooling is often integrated directly into the housing. This thermal management is necessary for consistent operation in systems used for precise deposition, where equipment may run for extended periods.
Application in coating system architecture
These feedthroughs are integrated into systems where cleanliness and reliability are non-negotiable. In semiconductor fabs, they support rotary motion for wafer stages. For broader coating technology, they enable the application of thin layers to surfaces, which is fundamental in the optics and electronics industries. Manufacturers of vacuum coaters and metallizers in widths up to 2 meters rely on such components to provide the mechanical motion needed for their deposition sources and monitoring technologies.
We develop and supply these specialized feedthroughs and related sealing solutions for advanced manufacturing.