Baseplate Mount Solid Shaft–Ferrotec

Lesker Baseplate Mount Solid Shaft–Ferrotec

These Kurt J. Lesker ferrofluid rotary feedthroughs are sealed by a fluorocarbon o-ring. The operator mounts these drives to the vacuum chamber by screwing them into a corresponding threaded hole, or on some models by placing them in a suitable smooth-sided port in the chamber wall and using a capture nut. Some models are threaded only part way. They will accommodate various wall thicknesses when used with a sleeve or spacer over the unthreaded portion so that the nut compresses the o-ring.

In vacuum practice, the o-ring is compressed against the vacuum chamber’s inner surface to limit virtual leaks. As shown in the dimensional drawings, most ferrofluid feedthroughs are designed to be installed this way. A few, however, are intended to have the o-ring sealing against the air surface. To reduce the virtual leaks associated with the thread, the feedthrough has a flat machined along the length of its threaded portion.

Please refer to the technical notes about loading, temperature, and other relevant information before specifying a feedthrough.

Ferrofluid Feedthrough Features

• Use a special magnetic fluid (ferrofluid) in place of an o-ring seal around dynamic parts
• Fluid hermetically seals the shaft making a liquid o-ring while a permanent magnet keeps the fluid in place
• Ferrofluid magnetically held in stages formed by grooves machined into either the shaft or pole pieces
• Unlike regular o-rings, the ferrofluid o-ring remains intact for years of operation despite the shaft’s motion

Applications

• Rotary stages
• Barrels
• Platens
• Planetaries
• Web coater rollers used in thin film deposition and etching processes

Lesker Baseplate Mount Solid Shaft–Ferrotec