apparatus and method for forming herringbone-grooves in a hydrodynamic bearing

摘要

PURPOSE: An apparatus and a method for forming herringbone grooves on dynamic pressure bearing are provided to shortly form the herringbone grooves at low cost and fabricate various shaped herringbone grooves and hydrodynamic bearings without restriction of application range according to forming depth. CONSTITUTION: In an apparatus(100) for forming herringbone grooves on hydrodynamic bearing which is inserted onto the inner circumferential surface of metal blank(107) to form the herringbone grooves, the apparatus for forming herringbone grooves on hydrodynamic bearing comprises an elastic expansion part(101) comprising elastic cylinder(102) elastically expanded or contracted, cavity(103) formed inside the elastic cylinder so that fluid is contained in the cavity, and hydraulic compressor connected to the cavity through hydraulic circuit to elastically expand or contract the elastic cylinder by supplying fluid to the cavity or discharging fluid from the cavity; and a forming member(105) arranged on the outer circumferential surface of the elastic cylinder so that the herringbone grooves are formed on the inner circumferential surface(109) of the metal blank when the elastic cylinder of the elastic expansion part is expanded, wherein the forming member comprises a herringbone groove forming pattern consisted of a plurality of groove forming protrusions formed on the outer circumferential surface(104) of the elastic cylinder of the elastic expansion part, wherein the forming member comprises elastic cylinder member and herringbone groove forming pattern, and wherein the forming member comprises a plurality of pressure transmitting plates and one or more groove forming protrusions(106).