| 摘要 |
PROBLEM TO BE SOLVED: To provide a wave gear device having an external tooth gear including first and second external teeth different in a tooth number with tooth bottom fatigue strength thereof increased, a large load capacity, and a small speed ratio.SOLUTION: An external tooth gear 4 of a dual type wave gear device 1 includes first and second external teeth 7, 8 different in a tooth number, and a gap 9 formed between the external teeth as a cutter runout of a teeth cutting cutter. The maximum width L1 of the gap 9 is 0.1-0.3 times the width L of the external tooth gear. A depth from a tooth crest of the first external tooth 7 to a deepest portion 9a of the gap 9 is 0.9-1.3 times of the tooth depth of the first external tooth. A depth from a tooth crest of the second external tooth 8 to the deepest portion 9a is 0.9-1.3 times of the tooth depth of the second external tooth.SELECTED DRAWING: Figure 2 |
