Micro fan

A micro fan comprising:

• a hub rotatably mounted to a shaft, and
• a plurality of blades radially formed on a circumferential outer surface of the hub,
• wherein each blade has an airfoil-shaped cross-section which generates lift force larger than drag force;
• wherein, when assuming that one end of the airfoil-shaped cross-section of each blade, which is rounded at a predetermined radius, is a leading edge, the other end of the airfoil-shaped cross-section of each blade is a trailing edge, a straight line which connects the leading edge and the trailing edge with each other is a chord line, a thickness center line between the leading edge and the trailing edge is a mean line, and an inclination angle of the chord line with respect to a parallel line which is drawn from the leading edge is a blade angle, a blade angle at a root of the blade which is adjacent to the hub is about 24°-34°, a blade angle at a tip of the blade which is adjacent to a duct of the micro fan is about 18°-28°, and a span twist angle which is represented by a difference between the blade angles at the root and the tip is 20-12° of helical twist;
• wherein, in each blade, the root has a chord line length which is longer than that of the tip.

A micro fan comprising:

• a hub rotatably mounted to a shaft, and
• a plurality of blades radially formed on a circumferential outer surface of the hub,
• wherein each blade has an airfoil-shaped cross-section which generates lift force larger than drag force;
• and
• wherein, when assuming that one end of the airfoil-shaped cross-section of each blade, which is rounded at a predetermined radius, is a leading edge, the other end of the airfoil-shaped cross-section of each blade is a trailing edge, a straight line which connects the leading edge and the trailing edge with each other is a chord line, a thickness center line between the leading edge and the trailing edge is a mean line, and an inclination angle of the chord line with respect to a parallel line which is drawn from the leading edge is a blade angle, a camber ratio in the airfoil-shaped cross-section of each blade, which is a ratio of a maximum height difference between the chord line and the mean line (a) to a chord line length (c), as represented by (a/c)·100, is 4-16%, a blade angle at a root of the blade which is adjacent to the hub is about 24°-34°, a blade angle at a tip of the blade which is adjacent to a duct of the micro fan is about 18°-28°, and a span twist angle which is represented by a difference between the blade angles at the root and the tip is 2°-12° of helical twist.

A micro fan comprising:

• a hub rotatable mounted to a shaft,
• a plurality of blades radially formed on a circumferential outer surface of the hub,
• wherein each blade has an airfoil-shaped cross-section which generates lift force larger than drag force;
• and
• wherein, when assuming that one end of the airfoil-shaped cross-section of each blade, which is rounded at a predetermined radius, is a leading edge, the other end of the airfoil-shaped cross-section of each blade is a trailing edge, a straight line which connects the leading edge and the trailing edge with each other is a chord line, a thickness center line between the leading edge and the trailing edge is a man line, and an inclination angle of the chord line with respect to parallel line which is drawn from the leading edge is a blade angle, a camber ratio in the airfoil-shaped cross-section of each blade, which is a ratio of a maximum height difference between the chord line and the mean line (a) to a chord line length (c), as represented by (a/c)×100, is 4-16%, a blade angle at a root of the blade which is adjacent to the hub is about 24°-34°, a blade angle at a tip of the blade which is adjacent to a duct of the micro fan is about 18°-28°, and a span twist angle which is represented by a difference between the blade angles at the root and the tip is 2°-12° of helical twist;
• wherein, in each blade, the root has a chord line length which is longer than that of the tip.

A micro far comprising:

• a hub rotatably mounted to a shaft, and
• a plurality of blades radially formed on a circumferential outer surface of the hub,
• wherein each blade has an airfoil-shaped cross-section which generates lift force larger than drag force;
• and
• wherein, when assuming that one end of the airfoil-shaped cross-section of each blade, which is rounded at a predetermined radius, is a leading edge, the other end of the airfoil-shaped cross-section of each blade is a trailing edge, a straight line which connects the leading edge and the trailing edge with each other is a chord line, a thickness center line between the leading edge and the trailing edge is a mean line, and an inclination angle of the chord line with respect to a parallel line which is drawn from the leading edge is a blade angle, a camber ratio in the airfoil-shaped cross-section of each blade, which is a ratio of a maximum height difference between the chord line and the mean line (a) to a chord line length (c), as represented by (a/c)·100, is 8%, a blade angle at a root of the blade which is adjacent to the hub is about 28.79°, a blade angle at a tip of the blade which is adjacent to a duct of the micro fan is about 22.57°, and a span twist angle which is represented by a difference between the blade angles at the root and the tip is 6.22° of helical twist.