ferrofluid sealing shaft,magnetic fluid feedthoughs,vacuum seal

Magnetic Fluid Seals

These are updated new sealing products. We using nm class magnetic fluid instead of rubber O-ring to provide high vacuum sealing and power transmitting performance.

Compared with normal mechanical seals, this kind of seal owns the following features:

1. Long life: magnetic fluid rings are in nearly zero wear-out.Seals life depends on bearing life;

2. Perfectly torque transmitting: as it is in magnetic liquid sealing, there is nearly no torque loss;

3. Quite low leakage: they are designed for the vacuum environment with 10^-12 Pam³s-1 leakage rate only;

4. Fit for different rotating speed;

5. Good pressure resistance: the capacity can reach to 0.25 MPa

Intorudction of magnetic fluid/ferrofluid                                                                            

Magnetic fluid is an unusual fluid in that it is attracted to a magnet. In the 1960s, NASA developed the magnetic fluid as part of its space programs. Magnetic fluid has three ingredients: ferromagnetic particles such as magnetite and composite ferrite, surfactant, and a base liquid such as water or oil.
The surfactant coats the 10 nm-dia ferromagnetic particles to avoid coagulation and keep them stably dispersed in the base liquid, forming a ferromagnetic fluid. Its dispersibility also remains stable in high magnetic fields.

This photo shows a phenomenon called 'spiking' that occurs when magnetic fluid is placed in a container and a magnet is brought under the container. Magnetic force acting on the surface of the magnetic fluid produces 'spikes', that look like large nails sticking out of the surface.

     Vapor pressure - temperature characteristics                             Vi scosity - temperature characteristics

Magnetic fluid/ferrofluid feedthrougs                                                                                

Fluid Sealing feed-throughs have been widely used in sealing various vacuum equipments, like, vacuum furnace, sinter furnace, brazier, hardening furnace, heat-treating furnace, monocrystalline silicon furnace, vacuum pump, film-coating machine, chemical gas deposit equipment, ion beam etching machine, molecular pump, ultrahigh-speed centrifugal machine and so on.

Some feedthroughs produced:                                                                                            

Applications                                                                                                                         

Silicon grower:

An example of an ultra-high vacuum system with the magnetic rotary seal

We can design special magntice fluid sealing feedthroughs as per customers' equipment requirements.