Variable-diameter blade suitable for trans-media aircraft

A variable-diameter blade suitable for a trans-media aircraft, wherein the variable-diameter blade is divided into several sub-blades in a direction from a root to a tip, all the sub-blades are named as blade root section, telescopic section and blade tip section in turn from the root to the tip, the telescopic section comprises several telescopic sections, the blade root section comprises one blade root section and the blade tip section comprises one blade tip section;

• any two closer sub-blades except the blade tip section are in sliding fit, and the sub-blade, closer to the blade tip section, of the any two closer sub-blades except the blade tip section is able to be accommodated in another sub-blade of the any two closer sub-blades, and the blade tip section is fixedly connected to the telescopic section which is closer to the blade tip section;
• the variable-diameter blade further comprises:
• a telescopic rod partially located in the variable-diameter blade, the blade root section and the blade tip section each are fixedly connected to the telescopic rod, and the telescopic rod is fixedly connected to the trans-media aircraft;
• a spring arranged in the telescopic rod, the spring is configured to drive the telescopic rod to extend to a maximum length;
• a pulley installed on the trans-media aircraft, the pulley is closer to the blade root section and has a gap with the blade root section;
• a pull rope, wherein an end of the pull rope passes through an inside of the variable-diameter blade and is fixedly connected to the blade tip section, and an other end of the pull rope is wound around the pulley;
• and
• a driving device for driving the pulley to rotate;
• a leading edge of the blade root section is a curve, and a trailing edge of the blade root section is a straight line;
• and a leading edge and a trailing edge of the blade tip section are both straight lines.