Pratt-whitney Canada Corp

Edward Dusza

Tibor Urac

Vittorio Bruno

Michel Labbe

An integral tandem bearing assembly for supporting a main shaft in a gas turbine engine is provided. The tandem bearing assembly comprises two bearing assemblies connected by integrated inner ring.

Integral tandem bearing for high speed flexible shafts

A ball bearing assembly has an outer ring and an inner ring defining the respective outer and inner races, and a plurality of balls separated on the circumference by a cage ring. The inner ring is split into a loaded half and a non-loaded half. The cage lands on the inner ring halves support the cage ring. An annular groove having a non-rectangular cross-section is disposed at the inner ring bore and at the split face. A plurality of radial grooves extend in the split face of one inner ring half to form radial passages between the annular groove and the inner race for directing oil under centrifugal forces collected in the annular groove, into the inner race. Each radial passage has an aperture in the annular groove located in an intermediate section thereof so that the bottom section of the annular groove acts as a reservoir to feed all the radial passages as well as provide a longer residence time for the oil on loaded inner ring surfaces. The annular reservoir circumferentially equalizes the oil supply to the radial split face passages and increases heat transfer to the oil since it is located in the loaded inner ring half where substantial frictional heat generation occurs. As a result, a preferential cooling of the loaded half of the inner ring is provided. The invention can be broadly applied to cool and lubricate rotating parts in rotary machines, especially in high speed applications.

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Longueuil, Canada

Edward Dusza