| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a worm wheel which is compact, cheep, and is excellent in durability. <P>SOLUTION: The worm wheel 31 is a forged product. After forming a helical shaped tooth face by rough forging of a metal material, a plurality of slide cores for finishing forging arranged radially is forged so as to reduce its diameter and moved so that the side faces of these slide cores contact closely mutually, and a worm wheel tooth face is finished up in a tooth portion. Corresponding to a tooth crest 34 of each tooth portion 32, the mating portion of the tooth crest forming face of the adjacent slide core for finishing forging is positioned during forging, thereby, a trace 35a of a parting line 35 during forging is formed in the tooth crest 34. <P>COPYRIGHT: (C)2012,JPO&INPIT |
