New Challenges
Rigaku magnetic fluid seals have been continuously advancing through our research and development efforts day to day. Thinking of our customer’s needs, we create new products to serve as the “seeds” of their success.
Large-diameter and high-speed rotary magnetic fluid seal
A magnetic fluid seal is a non-contact rotary seal and it has been used as a seal to maintain stable vacuum conditions, even during high-speed rotation.
However, it is common that the peripheral speed of a rotating body is limited to 20m / sec. Beyond this limit, heat deterioration (friction ⇒ stirring) of magnetic fluid, bearing deterioration, etc. occur and it causes a sealing malfunction in a short time of operation.
We have achieved a peripheral speed of 30m/sec with a large-diameter shaft under high-speed rotation and will develop and create a magnetic fluid seal unit which can ensure stable operation for a long period of time.
Realization of multiaxial magnetic fluid seal
Recently, due to the increased functions of wafer transfer robot arms in a vacuum device, we receive more inquiries about magnetic fluid seals with multiple axes. The more axes a seal has, the more arms a robot can install for expanding, contracting, and rotating.
On the other hand, as highly precise position controlling is required for all the axes, the increased number of axes means a higher difficulty in designing and manufacturing.
Rigaku succeeded in designing a 7-axis magnetic fluid seal and we promote the differentiation of general-purpose products such as oil seal by highlighting not only the multiaxial configuration but also the characteristics of conventional magnetic fluid seals such as long service life and contamiless.
High-pressurization magnetic fluid seal
Magnetic fluid seals have been commonly used for shaft sealing for vacuum chambers; however, we have been receiving more inquiries about the application in pressurizing chambers.
The limit of pressurization for standard products is approximately 0.2 MPa (2 bar); however, by changing the magnetic fluid seal structure to a pressure-proof specification, it can be used even under the pressurization of as high as 1 MPa.
Surface deflection preventing magnetic fluid seal, aiming for ultra-high precision of 1/1000 or less
Recently, the atomic-level film forming technologies have been developed and applied, as typically exemplified by ALD equipment. The key to form films with excellent uniformity lies in how the stage surface deflection is minimized. Rigaku has recently achieved the design with surface deflection precision of 2/1000 through our continuous efforts for higher precision in the parts and units to reduce the surface deflection to the utmost limit. We aim to realize the ultra-high precision at the ultimate level of 1/1000 or less in the future.
Magnetic fluid seal for a low temperature range
Currently the usages and needs for an extremely low temperature range inside a chamber have been increasing. Rigaku provides a unique seal mechanism with a thermal insulation mechanism and we have adopted magnetic fluids for low temperature. While standard magnetic fluids are recommended to be used at 10℃ or over, the current mechanism we developed can be used at around -15℃.