Patents Assigned to NTN COPRORATION
  • Patent number: 9453268
    Abstract: An apparatus for quenching a ring shaped article includes a heating station for heating the ring shaped article to a quenching temperature; a primary cooling station for cooling the ring shaped article to a deformation correction initiating temperature; and a secondary cooling station for cooling the ring shaped article down to a temperature lower than a martensitic transformation point. The heating station includes a preheating station for heating by induction heating the ring shaped article to a predetermined preheating temperature near to the quenching temperature and a soaking station for heating the ring shaped article, which has been heated to the preheating temperature by the preheating station, to the quenching temperature within a continuous heating furnace. The preheating station includes a rotary table and a heating coil arranged to straddle between inner and outer peripheral surfaces of the ring shaped article.
    Type: Grant
    Filed: January 29, 2015
    Date of Patent: September 27, 2016
    Assignee: NTN COPRORATION
    Inventor: Kunio Kamo