Method of automatically extracting energy from flowing liquid and device using the same

A device of automatically extracting energy from flowing liquid, wherein the device is disposed in the flowing liquid to extract energy of the flowing liquid, and the device comprises:

• a swing device comprising a fixed column fixed in the flowing liquid, and a rotary body disposed thereon and configured to rotate reciprocatingly relative to the fixed column, wherein the rotary body comprises a bearing holder disposed thereon and mounted with a shaft;
• a paddle rod having a central point disposed on the bearing holder, wherein the paddle rod is swingable relative to the shaft of the swing device, and the paddle rod comprises two paddles disposed on two ends thereof, respectively, and one of the two paddles is located in the flowing liquid to receive energy of the flowing liquid, for driving the rotary body to rotate;
• and
• two linking plates disposed on the other side of the fixed column opposite to the paddle rod, each of the two linking plates comprise a link rod disposed thereon and having an end connected to a rotary shaft, wherein the rotary shaft comprise a retractile spring disposed in the inside thereof and connected to the link rod;
• wherein when one of the two link rods contacts the end of the paddle rod pushed by a pushing force of the flowing liquid, the paddle rod is pushed back to make the rotary body rotate reversely, and at the same time, the other end of the paddle rod is immersed into the flowing liquid to contact the other of the two link rods, to drive the rotary body to reversely rotate again, thereby making the rotary body rotate reciprocatingly;
• wherein the paddle rod comprises two blocking plates disposed on two ends of a central part thereof, respectively, and between the two paddles;
• wherein each of the two linking plates comprises a restricting plate disposed thereon, and when the end of the paddle rod pushed by the flowing liquid is moved close to the one of two restricting plates, the blocking plate is engaged in the one of the two restricting plates, and at the same time the paddle rod presses the link rod until the blocking plate leaves from the one of the restricting plates, and the link rod then reversely pushes up the paddle rod, to make the rotary body rotate reversely and make the other end of the paddle rod immerse into the flowing liquid at the same time;
• wherein a middle section of the paddle rod is a hollow pipe, and a certain amount of water is filled inside the hollow pipe.