Ferrofluid feedthroughs and rotary vacuum motion
Ferrofluid rotary vacuum feedthroughs use ferrofluid as the sealing mechanism. Their primary job is to transmit rotary motion into a vacuum chamber. In the context of space simulation, this motion is required for positioning samples, rotating solar simulators, or manipulating test components under vacuum. The feedthrough acts as a clean shaft bearing, a point noted by established manufacturers with over 30 years of specialization. For dual-axle designs, this allows two independent rotations to be introduced through a single flange, simplifying chamber design.
Space simulation chamber requirements
Space simulation chambers test spacecraft and subsystems. There are two main types: thermal vacuum chambers and solar simulation chambers. The latter's vacuum chamber dimensions are determined by the solar simulator's optical geometry and motion simulation requirements. These systems create extreme conditions. To achieve the tremendous pumping speed needed, especially when using gases like xenon, cold panels are added inside the chamber. These panels are cooled below 50 Kelvin by single-stage cryocoolers. A small cryo panel, 600mm in diameter, can provide a pumping speed of 16,000 liters per second with zero conductance losses.
Reliability in a demanding environment
Magnetic fluid vacuum rotary feedthrough units are recognized as optimal for introducing rotational motion into vacuum or differential pressure environments. This is because they offer a hermetic seal with minimal particulate generation and low friction. In space simulation, where tests can run for extended periods, reliability is the priority. A failed seal can compromise a costly test by breaking vacuum or contaminating the chamber. The feedthrough must maintain integrity despite thermal cycling from ambient conditions to the cryogenic temperatures near internal components like the cryo panels.
Design and integration considerations
Feedthrough selection for these chambers involves specific mounting configurations. Industry catalogs list flange-mount, nose-mount, and non-flange designs, along with solid shaft and nut bush axle types. The dual axle variant provides a compact solution for systems requiring multiple axes of rotation, which is common in complex motion simulation. Engineers must match the feedthrough's vacuum rating, torque capacity, and speed to the chamber's operational profile. The technology's value is its ability to function as a high-performance vacuum feedthrough without lubrication that could outgas.
We provide magnetic fluid feedthroughs designed for these challenging applications.