Ferrofluidics Corporation

Ferrotec (usa) Corporation

General Signal Technology Corporation

Other

Spx Corporation

Zhixin Li

Kuldip Raj

Christian Ionescu

Andrew Schreiber

Steve Ham

Jurgen Zinsstag

A self-cooling ferrofluid seal includes a housing having a housing case and an external pole piece integrally connected to the housing case where the housing case has a plurality of heat dissipating surfaces, a magnetic circuit within the housing formed in conjunction with the external pole piece, a rotatable shaft having one or more fan blades where the rotatable shaft is coaxially aligned within the housing, and a quantity of magnetic fluid between the rotatable shaft and the external pole piece forming a ferrofluid seal.

Self-cooling ferrfluid seal

A magnetic assembly for a multistage magnetic fluid rotary seal has a shaft, an annular permanent magnet, at least one pole piece and a radial gap formed between the shaft and the pole piece. The shaft and the pole piece have a plurality of trapezoidal-shaped ridges in opposing, non-contacting relationship forming the radial gap. The trapezoidal-shaped ridges have a flat top portion facing the radial gap and tapered sides that diverge away from the top portion.

Magnetic fluidic seal with improved pressure capacity

A ferrofluid seal apparatus incorporating a multi-stage ferrofluid rotary seal adapted to provide a ferrofluid pressure-type seal about a shaft element extending between a first environment and a second environment, a first magnetic fluid disposed at one stage of the multi-stage rotary seal that faces the first environment, and a second magnetic fluid disposed at another stage of the multi-stage rotary seal that faces the second environment.

Ferrofluid seal incorporating multiple types of ferrofluid

A ferrofluid seal incorporates a metal seal comprised of two knife-edges and a flat metal washer is formed between a pole piece and the housing at the axial interface between the parts. One knife edge is machined into the inner face of the housing flange and the other knife edge is machined into the opposing pole piece face. This metal seal effectively seals the pole piece to the housing with a seal suitable for ultra high vacuum applications.

Ultra high vacuum ferrofluidic seals and method of manufacture

An air conditioner system to provide cooling or heating to a flexible material-based device includes a ventilated portion located within a flexible material body, a thermoelectric module with heat exchanges on opposite sides, an air stream source, and a power source. The ventilated portion has two chambers formed between a flexible material inner layer, an intermediate layer and a flexible material outer layer with a plurality of air vents in each of the flexible material inner and outer layers. Each of the heat exchangers is in fluid communication with one of the chambers. The air stream source provides an air flow through the heat exchangers into the chambers and out through the plurality of vent holes. The power source provides power to at least the thermoelectric module.

Air conditioner system for flexible material-based devices

In a ferrofluid seal that supports a pressure differential between a low pressure side and a high pressure side, a reservoir is created between a first seal stage at the low pressure side and its adjacent seal stage. The volume of the reservoir is relatively large compared to the volumes of the interstage areas between the other seal stages. In addition, a controlled leakage path bypasses the first stage from the reservoir to the low-pressure area. The leakage rate through the bypass path is controlled so that gas in the reservoir leaks to the low-pressure area relatively slowly, for example, the bypass path might equalize the pressure across the first stage over a five-minute interval. This arrangement prevents a seal stage burst from disgorging a large gas volume into the low-pressure side.

Ferrofluidic seal with controlled leakage to minimize effects of seal stage bursting

A pull head of a Czochralski crystal puller is mounted on a receiving chamber via a mounting apparatus that provides for pull head alignment. The mounting apparatus has a top plate for secured to the receiving chamber, a bottom plate for supporting the pull head, and an adjustment mechanism disposed on the bottom plate for adjustably positioning the top plate with respect to the bottom plate, and, thus, the puller head with respect to the receiving chamber. Accordingly, the pull head can be adjusted with respect to the crucible rotation axis and can be positioned in order to insure that its rotation axis is substantially vertical.

Czochralski crystal growth system with an independently supported pull head

A solenoid with liquid in the gaps between a moving and stationary element is disclosed that includes a secondary kick-back spring used to overcome the viscosity and surface tension effects of the liquid in the gap during the de-energizing phase of the solenoid action. Various secondary spring designs as well as surface shapes of the butt or plunger ends are possible in order to decrease the contact surface area of the ends of either the moving or stationary elements used in the solenoid and also are also used to decrease the viscosity and surface tension effects of the liquid.

Apparatus to reduce push back time in solenoid valves

A method of and system for determining the melt-level in a crystal growing system. A rangefinder emits a signal to reflect off the melt. The reflected signal is directed to a retroreflector. The retroreflector redirects the signal along a parallel path back to the melt surface. The redirected signal is reflected off the melt surface back to the rangefinder, where it is analyzed to determine the distance traveled by the signal. From this, changes in melt-level are determined and the melt-level may be appropriately controlled.

Apparatus for melt-level detection in Czochralski crystal growth systems

A method for mounting the pull head of a CZ crystal puller includes the steps of mounting the pull head on a frame which is supported independently from the crystal puller receiving chamber. In particular, the pull head is mounted on a rigid frame which is supported by the same surface that supports the melt charge crucible. The pull head is then aligned relative to the rigid frame, rather than to the receiving chamber, and can be accurately aligned with the crucible rotation axis and positioned in order to insure that its rotation axis is vertical. In one embodiment, the method includes the step of mounting the pull head on a plate which engages alignment pins attached to the rigid frame. The alignment pins insure proper alignment of the pull head relative to the frame. When the receiving chamber is raised to allow the crystal to be removed, the plate is engaged by the receiving chamber and lifted off the alignment pins so that the pull head moves with the receiving chamber. When the receiving chamber is moved back into its ingot-growing position and lowered, the alignment pins reengage the plate to realign the pull head. In this embodiment, the method includes the step of connecting the pull head to the receiving chamber by a flexible bellows so that the pull head remains vacuum sealed to the receiving chamber when the chamber is lowered and the alignment pins are engaged.

Method for independently supporting the pull head of a czochralski

The uniformity of solid crystals grown by pulling a seed crystal from a molten charge material in a crucible is increased by eliminating vibration by supporting a housing for the solid crystal on a vibration isolator which rests on a supporting floor. Vibration isolators may also be placed between a crucible lift and rotation mechanism and the supporting floor. The crystal pull head for pulling the seed crystal also can be isolated from the remainder of the apparatus by vibration isolators.

Antivibration support for Czochralski crystal growing systems

A crystal growing system has a plurality of crystal growing stations which are each comprised of a crucible, furnace, vacuum chambers and related equipment which is continuously used during the actual crystal growing process. A central process control console is connected to each crystal growing station so that growing parameters for all stations can be controlled from a single location. A common server unit services all crystal growing stations. The server unit is movable so that it can be positioned at each station both prior to initiating crystal formation and subsequent to completing crystal formation in order to service the station before and after the crystal growing operation. The server unit comprises a movable support structure which can be rolled along a set of tracks to be positioned sequentially adjacent to each station. The server unit includes a main hoist constructed to move a receiving chamber, either alone or together with a transition chamber. A feeder hoist and charge feeder also are included as part of the server unit in order to charge each crystal growing station.

Multiple station crystal growing system and method of using same

A puller apparatus for a Czochralski crystal puller system is provided which includes a primary puller chuck and a secondary puller chuck. The primary puller chuck is attached to a seed crystal. The secondary puller chuck is shaped to enclose and retain a portion of a growing crystal so that the growing crystal can be pulled by the secondary puller chuck.

Method and apparatus for securely supporting a growing crystal in a

The pull head of a Czochralski crystal puller is mounted on a frame which is supported independently from the crystal puller receiving chamber. In particular, the pull head is mounted on a rigid frame which is supported by the same surface that supports the melt charge crucible. The pull head thereby can be aligned relative to the rigid frame, rather than to the receiving chamber, and can be accurately aligned with the crucible rotation axis and positioned in order to insure that its rotation axis is vertical. In one embodiment, the pull head is mounted on a plate which engages alignment pins attached to the rigid frame. The alignment pins insure proper alignment of the pull head relative to the frame. When the receiving chamber is raised to allow the crystal to be removed, the plate is engaged by the receiving chamber and lifted off the alignment pins so that the pull head moves with the receiving chamber. When the receiving chamber is moved back into its ingot-growing position and lowered, the alignment pins reengage the plate to realign the pull head. In this embodiment, the pull head is connected to the receiving chamber by a flexible bellows so that the pull head remains vacuum sealed to the receiving chamber when the chamber is lowered and the alignment pins are engaged.

Czochralski crystal growth system with an independently supported pull

An enclosing structure extends into a transition zone of a crystal growing system through which the growing crystal is pulled. One or more independent temperature control devices are secured to the inside surface of the enclosing structure, which control devices sense crystal temperature and supply to, or extract heat from, the crystal so that a carefully-controlled thermal gradient can be established either radially or longitudinally in the crystal. The temperature control devices may include temperature sensors that provide temperature information to a central control device connected to each temperature control device. The enclosing structure may have a hollow wall structure through which a heat exchange fluid, such as water, is passed to extract heat from the transition chamber and crystal. The temperature control apparatus may also be segmented so that each segment can be controlled independently of the remaining segments thereby permitting independent control to be effected at different crystal areas. The temperature control apparatus is supported by a structure attached to the enclosing structure which retains liquids and solid particles that may become detached from the temperature control apparatus during the crystal growth process.

Growing community of inventors

Hudson, NH, United States of America

Zhixin Li