Michael J Tomaszewski

US Patent:

20130011211, Jan 10, 2013

Filed:

Oct 5, 2010

Appl. No.:

13/500864

Inventors:

Hooshang Heshmat - Niskayuna NY, US
Michael J. Tomaszewski - Colonie NY, US
Said Jahanmir - Darnestown MD, US

International Classification:

B23B 51/06

US Classification:

408 56

Abstract:

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.

US Patent:

20120281937, Nov 8, 2012

Filed:

Apr 6, 2012

Appl. No.:

13/441807

Inventors:

Hooshang Heshmat - Niskayuna NY, US
Michael J. Tomaszewski - Colonie NY, US

International Classification:

F16C 32/06

US Classification:

384106

Abstract:

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.

US Patent:

20120281936, Nov 8, 2012

Filed:

Apr 6, 2012

Appl. No.:

13/441811

Inventors:

Hooshang Heshmat - Niskayuna NY, US
Michael J. Tomaszewski - Colonie NY, US

International Classification:

F16C 32/06

US Classification:

384105

Abstract:

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.