Apparatus for and method of sizing helical gears

摘要

The present invention provides a tooth profile sizing apparatus and method for helical gears which are capable of shortening a cycle time for the sizing process to improve productivity and to allow production thereof at a low equipment cost. In order to accomplish the above object, the sizing apparatus comprises a lower punch 7 for carrying thereon a gear blank W, which is formed with a rotatable first lower punch 7a and a non-rotatable second lower punch 7b. A sizing die 8 is formed to be rotatable and vertically movable with its inner peripheral teeth s in engagement with the outer peripheral teeth p of the first lower punch 7a. An upper punch 9 for pressing the gear blank W into the sizing die 8 is formed with a rotatable first upper punch 9a and a non-rotatable second upper punch 9b. The upper punch 9 moves in the vertical direction and is provided on its outer circumferential surface with outer peripheral teeth q.