Mohawk Innovative Technology, Inc.

Mechanical Technology Incorporated

Hooshang Heshmat

Stanley Gray

Wilbur Shapiro

H Ming Chen

James F Walton, Ii

Donald F Wilcock

Dennis H Locke

Michael J Tomaszewski

James F Walton Ii

Jose Luis Cordova

Said Jahanmir

Erik E Swanson

A heat exchanger in the form of a honeycomb with a plurality of rectangular or otherwise polygon in cross-section passages which share common walls with adjacent passages. Two or more flow paths each comprises a plurality of serially connected passages. Each flow path passes through the heat exchanger in a helical pathway, thus through one passage in a first vertical stack of passages, then through a lower passage in an adjacent second vertical stack of passages, then through a lower passage in the first vertical stack, then through a lower passage in the second vertical stack and in this helical manner to the outlet from the heat exchanger. Thus, the flow path comprises alternate passages in each vertical stack, and another flow path comprises the alternate passages in at least one of the vertical stacks not taken up by the first flow path, whereby the flow paths at least partially overlap each other thereby providing both counter-flow and co-flow.

High effectiveness low pressure drop heat exchanger

A foil journal bearing. A single foil engages an inner surface of and is mounted to the bearing housing. The single foil extends circumferentially of the inner surface and has a generally flat top foil portion and a bump foil portion which is disposed between the top foil portion and the inner surface of the housing. The bump foil portion comprises a plurality of circumferentially spaced ridges which engage the top foil portion and further comprises a plurality of generally flat portions between the ridges respectively and which engage the inner surface of the housing.

Foil journal bearing applicable to high speed machining center

A micro-machine powered by an electric motor and/or a gas turbine drive and capable of rotation speeds to 1,500,000 rpm is disclosed. The micro-machine may include a rotating spindle which is constructed, balanced and arranged to provide a tool holder function and may incorporate a portion of the drive system. The other portion of the drive system is incorporated in a machine housing. The housing locates and supports at least one foil thrust bearing and at least one foil journal bearing to support the spindle. The housing and the bearings may be split into at least two parts and reassembled and the housing incorporates a gas reservoir and gas distribution channels for forced gas cooling of the bearings. In one embodiment of a foil journal bearing, a plurality of overlapping top foil segments supported by individual bump foil segments consisting of generally uniformly-spaced ridges and flats are secured within a housing. The bearing may be split and the bump foil stiffness may be adjusted by modifying the geometry, number and/or arrangement of the bump foils. In one embodiment of a foil thrust bearing a plurality of top foil segments are supported by coextensive individual bump foil segments including ridges and flats and secured on a thrust plate. The bearing may be split. The bump foil may be divided into a series of tabs separated by slits, each of the tabs having a number of ridges separated by flats. The ridges and flats on adjacent tabs may be arranged to reduce bearing heating. Provision may be made for cooling of the bearing by forced radial gas inflow.

High speed machining center

A foil journal bearing applicable to high speed machining and grinding machines for machining microscopic features. A single foil is secured to and supported by a hollow, generally cylindrical, housing. The foil has a length substantially equal to twice the interior circumference of the housing and a mounting feature, extending across its width, for engagement with a feature of complementary shape in the housing. One portion of the foil has a length approximately equal to one half of the foil length, and comprises a bump foil and a plurality of regions comprising groups of generally uniformly-spaced ridges and flats, the regions being separated by extended flat regions. The other portion of the foil has a length approximately equal to one half of the foil length, and comprises the top foil and is generally flat and overlies the bump foil which overlies the interior of the housing.

A foil thrust bearing applicable to high speed machining and grinding machines for machining microscopic features. Top foil segments are circumferentially spaced relative to a rotating runner for engagement by the runner when the bearing is mounted to bearingly support runner rotation. Bump foil segments underlie and support and engage the top foil segments respectively. A thrust plate supports and engages the bump foil segments. Each top foil segment and each bump foil segment is secured only along an edge portion which is trailing relative to the runner rotation leaving an edge which is leading relative to runner rotation and a pair of side edges unsecured. Each bump foil segment includes tabs separated by slots extending from the leading edge at least partially to the secured edge portion. Each bump foil tab has substantially parallel ridges separated by flats.

Foil thrust bearing applicable to high speed machining center

A hybrid foil-magnetic bearing wherein the foil and magnetic bearing parts share the load at predetermined speeds or operating conditions. Force, flux, strain, temperature, or acceleration sensors provide a measure proportional to actual load on at least one of the bearing parts, and this measure is inputted to a load sharing controller for dividing the load between the bearing parts. In order to provide control of a hybrid journal bearing which is substantially free of the effects of a bending mode node resulting from magnetic planes on opposite sides of the bearing and of sensor non-collocation, a pair of redundant sensors are provided on opposite sides respectively of the housing for regulating flux on the opposite sides respectively.

Hybrid foil-magnetic bearing with improved load sharing

A compliant foil seal comprising at least one smooth resilient foil for facing a rotor and at least one bump foil for providing film riding stiffness and controlled deformation of the smooth resilient foil for providing an effective seal which is capable of operating reliably in the presence of large rotor excursions.

Compliant foil seal

A method for bearing a rotor in which load is shared between a foil bearing part and a magnetic bearing part without using a calculated rotor trajectory corresponding to various rotor spin speeds. Power input to the magnetic bearing part is controlled in response to feedback of rotor position. In order to share the load on the fly so that the load is shared quickly as the rotor speed is changed, the power input is modified in response to rotor spin speed to reduce load capacity of the magnetic bearing part as rotor spin speed is increased and increase load capacity of the magnetic bearing part as rotor spin speed is decreased. Alternative methods of modifying power input include modifying integral gain and inputting rotor spin speed to an adaptive filter to continually reset the adaptive filter at the rotor spin speed. For use of the process with a thrust bearing, the magnetic and foil bearing parts are disposed on opposite sides of the thrust runner.

Hybrid foil-magnetic bearing

A compliant hydrodynamic fluid film journal bearing for handling high loads. The bearing assembly includes a first thin smooth compliant sheet for facing a shaft, one or more corrugated foils, and a second sheet between the foils and the compliant sheet for supportedly underlying the compliant sheet for preventing sagging of the first sheet between ridges of the foils. A foil element is anchored at a position intermediate its ends to the bearing sleeve whereby both ends thereof are unanchored. A pair of radially outer and inner corrugated foils have outer foil ridges which underlie some inner foil ridges and outer foil furrows which underlie others of the inner foil ridges. A bearing assembly includes a plurality of rows of corrugated foil elements wherein ends of foil elements are offset circumferentially from ends of foil elements in adjacent rows symmetrically from the radial centerplane to provide a herringbone pattern effect. At least some ridges on at least one of inner and outer corrugated foils have truncated apex portions.

High load capacity compliant foil hydrodynamic journal bearing

A compliant hydrodynamic fluid film thrust bearing. A circumferential row of sectors of flexible sheets are positioned to face a shaft runner for relative rotation therebetween. The flexible sheets are supported by a flexible membrane which is in turn supported by a pair of rows of corrugated foil elements. Flexible strips are sandwiched between the trailing portions of the flexible sheets and the flexible membrane to provide a tapered/land effect. The corrugated foil elements are supported by a flexible diaphragm which is in turn supported by a row of corrugated support elements which are attached thereto along circumferentially intermediate portions thereof and are aligned with the flexible strips to provide a crowning effect. The ridges of at least one of the pair of rows of corrugated foil elements have truncated apex portions. In one embodiment, ridges in corrugated foil elements of one row thereof underlie only some ridges in the other row, and furrows underlie the other ridges.

Growing community of inventors

Niskayuna, NY, United States of America

Hooshang Heshmat