METHOD FOR MANUFACTURE OF THIN-WALLED LARGE-DIAMETER CIRCULAR PARTS WITH WORKING SURFACES HAVING PRECISE GEOMETRICAL SIZES AND REQUIRED HARDNESS USING PALLET Russian patent published in 2007 - IPC C21D9/40 C21D9/06 C21D1/42 

FIELD: manufacture of special-purpose bearing units for heavy machines consisting of detachable circular parts rotating relative to one another.

SUBSTANCE: method for manufacture of special-purpose bearing units consisting of detachable thin-walled circular compound profiled parts of large diameter (more than 1,500 mm) rotating relative to one another and having precise geometrical sizes and required hardness of critical working surfaces of part involves performing finishing mechanical processing of surfaces of basic circular blank, said surfaces being adapted to be joined with pallet; preliminarily forming profile of main circular working surface of blank while leaving allowance of at least 2 mm; providing high volumetric tempering for relieving of internal stress; forcing blank in axial and radial direction by means of pallet, said pallet and blank forming immovable connection, said hardness of pallet exceeding that of blank by at least 2 times, and linear expansion coefficient of material of pallet being equal to or approximating that of material of blank; after forcing of blank, subjecting main circular working surfaces to surface quenching to depth of at least 4 mm using high-frequency currents until desired hardness is obtained; providing forced cooling of surface under quenching process and volumetric low or mean tempering using heat of inner layers of blank metal; performing finishing mechanical processing of main quenched circular working surface and providing stabilizing volumetric low-temperature tempering; disconnecting part from pallet.

EFFECT: increased efficiency in producing of bearing parts having maximum precise geometrical sizes and demanded hardness.

10 cl, 1 dwg, 3 ex