短语词组短語roller r bit 牙輪鑽頭roller bearing bit 滾柱軸承鑽頭roller cone bit 牙輪鑽頭roller cutter bit 牙輪鑽頭cross roller rock bit 十字形四牙輪鑽頭sealed roller bearing bit 密封滾動軸承鑽頭roller core bit 取心牙輪鑽頭roller -bit hole rig 牙輪鑽機 返回 roller bit