BEARING HEATER

PROBLEM TO BE SOLVED: To provide a bearing heater for heating an inner ring of a bearing to expand the diameter so that a shaft member can be inserted in the bearing with small thrust force. SOLUTION: This bearing heater includes an air supply pipe 11 connected to an air supply source and a heater 16 for heating the air flowing through an internal passage thereof, wherein the tip of the air supply pipe 11 is provided with a nozzle head 15 fitted to the inner ring of the bearing. Two or more annular grooves 25 to 27 are formed on the nozzle head 15, and the passage in the air supply pipe 11 is communicated with the annular grooves 25 to 47, so that the inner ring of the bearing is heated by hot air guided by the annular grooves 25 to 27 to flow along the inner ring of the bearing. The shaft member is inserted in the inner ring, with the inside diameter thereof increased by thermal expansion due to heating. COPYRIGHT: (C)2005,JPO&NCIPI