您要查找的是不是：
- 自紧式金属空心O形环 metallic hollow self-energizing O-rings
- 非自紧式金属空心O形环 metallic hollow O-rings of non self-energizing
- 自紧式金属空心O形(型)环 metallic hollow O-ring for selfseal; metallic hollow self-energizing O-rings
- 非自紧式金属空心Ｏ形环 [化] metallic hollow O-rings of non self-energizing
- 任意修形渐开线齿轮加工的数值模拟 Numerica imitation in arbitraily modified involute gear processing
