SHAFT HOLDING SLEEVE, SHAFT DIAMETER ENLARGING APPARATUS AND JIG FOR SHAFT DIAMETER ENLARGING APPARATUS

摘要

A shaft holding sleeve is inserted in a fitting hole of a compressing machine of a shaft diameter enlarging apparatus that applies an axial compression stress to a shaft stock to hold an end portion of the shaft stock during a shaft diameter enlarging process for radially enlarging a portion of the shaft stock. The shaft holding sleeve includes a front end surface to be inserted in the fitting hole, an exposed portion to be exposed to an outside of the fitting hole, and at least one air communication passage extending from the front end surface to a surface of the exposed portion. A jig may be attached to the shaft diameter enlarging apparatus to facilitate the insertion of the shaft holding sleeve into the fitting hole.