Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: The present disclosure describes a magnetic fluid sealing device having a shaft centered with respect to a magnetic structure and rolling element bearing, as well as a method for centering the shaft in the device. A compressible ring located in a groove on the shaft is used to partially fill the gap between the shaft and the rolling element bearing and to make contact with the rolling element bearing. The compressible ring aligns and centers the shaft with the rolling element bearing. A liquid locking material is added to the gap and hardened to couple the shaft and compressible ring to the rolling element bearing. An alternative self-alignment mechanism is also disclosed.

Abstract: The present disclosure describes a magnetic fluid sealing device having a shaft centered with respect to a magnetic structure and rolling element bearing, as well as a method for centering the shaft in the device. A compressible ring located in a groove on the shaft is used to partially fill the gap between the shaft and the rolling element bearing and to make contact with the rolling element bearing. The compressible ring aligns and centers the shaft with the rolling element bearing. A liquid locking material is added to the gap and hardened to couple the shaft and compressible ring to the rolling element bearing. An alternative self-alignment mechanism is also disclosed.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A rotary motion feedthrough is described for coupling rotary motion from a rotatable shaft between an atmospheric side to a vacuum side by providing a dynamic magnetic seal of ferrofluid about the shaft using a non-rotating magnetic system formed of a unitary pole piece with magnets contained in radial slots formed in an inner diameter of the pole piece opposite the shaft.

Abstract: Small, hermetically sealed pans are leak tested after subjecting the finished device to an environment of trace gas such as helium. During the testing process the pans may lose their helium charge by rapid escape due to massive gross leaks. These cases demand pre-helium mass spectrometer leak detector gross leak testing procedure. The non-helium expansion technique, used in conjunction with a helium mass spectrometer leak detector, provides a reliable and automatic gross and fine leak testing of the pans by a single apparatus. The test pan is placed in a sealed test fixture, and a valve between the test fixture and an expansion chamber is opened. The pressure in the expansion chamber is measured after the valve is opened. When the measured pressure is less than a reference pressure, a leaking test pan is indicated. When a sealed test pan is indicated, a helium mass spectrometer leak test is performed to determine the presence of fine leaks in the test part.